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Factors Related to Induced Abortion among Young Women in Edo State, Nigeria Nancy Murray, William Winfrey, Minki Chatterji, Scott Moreland, Leanne Dougherty, and Friday Okonofua Sub-Saharan Africa has the highest death rate from induced abortion in the world, and young women in southern Nigeria are particularly likely to terminate their pregnancies. This study assesses the prevalence of and factors associated with induced abortion among 601 young women aged 15–24 who were surveyed in Edo State, Nigeria, in 2002. We find that 41 percent of all pregnancies reported by the young women surveyed were terminated, and we estimate the age-specific abortion rate for 15–19-year-olds in Edo State at 49 abortions per 1,000 women, which is slightly higher than previous local estimates and nearly double the countrywide estimate for women aged 15–49. We construct explanatory multivariate models to predict the likelihood that a young woman has experienced sexual intercourse, has become pregnant, and has undergone an induced abortion, controlling for important demographic and risk-behavior factors. Young women unmarried at the time of the interview are found to be significantly more likely than married women to have had an abortion. Young women who have experienced transactional or forced sex are also significantly more likely to report ever having had an abortion, as are young women who have experienced more than one pregnancy. We conclude with suggestions for modifying the content and target populations of behavioral change messages and programs in the area. (STUDIES IN FAMILY PLANNING 2006; 37[4]: 251–268)

With an estimated 680 deaths per 100,000 procedures, sub-Saharan Africa has the highest death rate from induced abortion in the world (AGI 1995). In many subSaharan countries, abortion is most common among young unmarried women, and it results in relatively higher morbidity and mortality in this group (MakinwaAdebusoye et al. 1997; Zabin and Kiragu 1998; Bankole et al. 1999; Mutungi et al. 1999; Silberschmidt and Rasch 2001; Calvès 2002). To combat this problem, research is needed to investigate rates of and factors associated with induced abortion among young women in the region. Representative data on abortion in Africa are often difficult to obtain. Because abortion is illegal or available

Nancy Murray is Senior Scientist, William Winfrey is Senior Scientist, Minki Chatterji is Senior Research Specialist, and Scott Moreland is Senior Fellow, Constella Futures, One Thomas Circle, NW, Suite 200, Washington DC 20005. E-mail: [email protected]. Leanne Dougherty is Monitoring and Evaluation Manager, Private Sector Partnerships One, Abt Associates, Bethesda, MD. Friday Okonofua is Executive Director, Women’s Health and Action Research Center (WHARC), Benin City, Edo State, Nigeria.

only under restrictive circumstances in many African countries, few nationally representative surveys have been able to quantify the extent of women’s reliance on abortion. Most of the studies of abortion in the region are based on hospital admissions data and on small quantitative and qualitative studies. Although these data provide information about women who terminate their pregnancies, they are often based on nonrepresentative samples of women at risk. The first goal of this study, therefore, is to present new data on rates of induced abortion among a sample of young women in the region. The literature concerning the factors influencing a young woman’s decision to terminate a pregnancy also contains significant limitations. Much of this research is based on interviews with population subgroups such as students or women visiting a health clinic or hospital for abortion-related complications (Barker and Rich 1993; Renne 1997; Otoide et al. 2001; Silberschmidt and Rasch 2001; Varga 2002). In none of the studies reviewed in this paper are the factors associated with induced abortion examined independently of the risk of becoming pregnant. Therefore, determining whether the factors identified as influencing abortion are confounded by the factors associated with a young woman’s risk of being sexually active or becoming pregnant is difficult. The second aim of this study, therefore, is to develop and apply em-

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pirically an analytical model identifying the factors associated with each of three steps along the path toward induced abortion: onset of sexual activity, pregnancy, and having an induced abortion. We apply this model to the analysis of data collected in 2002 by the Women’s Health and Action Research Center (WHARC) in a household survey of 1,867 men and women aged 10–24 in Edo State, Nigeria.

Reproductive Health of Young People in Nigeria and in Edo State Nigeria is the largest country in sub-Saharan Africa, with an estimated population of 118 million in 2000. Past high fertility has resulted in a youthful age structure; some 20 percent of the population is between 15 and 24 years old. Nearly 40 percent of births in Nigeria are to women in this age group. Contraceptive use is generally low; the overall prevalence of modern method use is less than 10 percent (National Population Commission and ORC Macro 2004). The contraceptive prevalence rate among unmarried women in the 15–19 age group is 23 percent; it is 40 percent among those aged 20–24. Nevertheless, the incidence of unintended pregnancy is high. Nigerians both marry and start their reproductive lives at an early age, thereby exposing themselves to reproductive and sexual health risks while young. According to the 2003 Nigeria Demographic and Health Survey (NDHS), 25 percent of women aged 15–19 are either mothers (21 percent) or are pregnant with their first child (4.3 percent). Among women aged 25–29, the median age at first birth is 20. Fifty-one percent of all 15–19-yearold females report that they have had intercourse, and 20 percent of these sexually experienced teens report that their first intercourse occurred by age 15. In contrast, only 25 percent of adolescent men report that they were sexually experienced, a difference that is attributed to later marriage among males. Among young women aged 20–24, nearly three-fourths (74 percent) report having sexual experience by age 20. Edo State, one of 36 Nigerian states, lies in the SouthSouth geopolitical zone in the Niger Delta. In 1999, the state had an estimated population of 2.86 million. Edo State remains one of the poorest and least industrialized states. More than 60 percent of the population are peasant farmers. The state government derives its main resources from the federal government; few are generated internally. Edo State was once the largest producer of rubber and timber in Nigeria and is still well known for its proficiency in indigenous art, but these activities have not been developed recently to any substantial extent.

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Although the current state government has identified industrialization as a priority, the policy has yet to generate results (WHARC/Policy Project II 2002). Edo State’s literacy rate of 70 percent greatly exceeds the national rate of 40 percent. Thus, a large number of literate young people are qualified to enter the workforce, but few industries exist in the state, and few opportunities can be found to earn a living wage. As a result, the levels of unemployment and underemployment among young people in Edo State are among the highest in the country and are responsible for considerable social unrest (WHARC/PolicyII 2002) and for increasing the likelihood that young people will engage in risky behavior. A recent survey conducted in Edo State revealed that 83 percent of adolescents aged 10–20 are enrolled in school (Okonofua et al. 2003). The rate of school enrollment for girls is significantly less than that for boys, however. A high dropout rate is observed between the ages of 16 and 19 years; only a 50 percent school enrollment is recorded for this age group during this period. Dropouts occur frequently between primary and secondary levels and between secondary and tertiary levels because parents cannot afford to continue their children’s education (Okonofua et al. 2003). Nevertheless, Edo State’s rates of school enrollment for young adults are among the highest in Nigeria. Despite some favorable sociodemographic characteristics of young adults in Edo State, their reproductive health indicators are poor. Several reports indicate that young adults are highly active sexually and that they engage in extremely risky sexual behaviors (Otoide et al. 2001). The mean age at sexual debut reported for those aged 20 and younger in parts of Edo State is similar to the age reported for other states (14.5 years for boys in Benin City, compared with 13.5 years for boys in Ibadan, Oyo State; 15.8 years for girls in Benin City, compared with 15.2 years for girls in Ibadan). In a communitybased study in Benin City, 66 percent of boys and 63 percent of girls aged 10–20 reported that they were sexually active (Okonofua et al. 2003). These figures are similar to those from other states in southern Nigeria (Akinyemi and Koster-Oyekan 1996). Although the level of sexual activity among young adults in Edo State is high, available evidence suggests a low level of contraceptive use, especially of condom use. As much as 90 percent of young people are aware of contraceptives, including condoms, yet only about 34 percent report that they use condoms. Many of them may be using condoms incorrectly and inconsistently. Very few young women in Edo State use hormonal contraceptives, because they believe that such methods may

lead to infertility in later life (Otoide et al. 2001). Thus, female adolescents often experience unintended pregnancies for which they seek abortion (Otoide et al. 2001).

Literature on Induced Abortion and Its Correlates in Nigeria Nigeria’s high maternal mortality rate, estimated at 800 per 100,000, is influenced by large numbers of poorly performed abortions (AGI 2005). Induced abortion is estimated to account for 20,000 of the 50,000 maternal deaths in Nigeria each year (Otoide et al. 2001). In Nigeria, according to data concerning complications due to abortion, adolescents obtain more than half of reported abortions, although they represent only approximately one-fourth of the number of women of reproductive age (Bankole et al. 1999). Nigeria is virtually the only sub-Saharan African country where abortion is illegal for which we have a national estimate of induced abortion. From interviews with providers at 672 health facilities, Henshaw and his colleagues (1998) estimated an annual rate of 25 abortions per 1,000 women aged 15–44. The rate varies dramatically across the four regions surveyed, with the Southwest region reporting a rate of 46 abortions per 1,000 women, and the Southeast region reporting 32 abortions per 1,000. In the Southwest, the ratio of treatment for complications from abortions to that for miscarriages is higher than that for any other region. Approximately 60 percent of all abortions are performed by providers other than physicians, and many of these providers have not received training in safe abortion procedure. A recent research brief produced by the Alan Guttmacher Institute examines the levels of mistimed and unwanted births in Nigeria using the 1999 and 2003 NDHSs and sheds some additional light on the regional differences in the country’s abortion rates.1 This study found that women in the South-South (situated between the South-West and South-East geopolitical regions) and South-East regions have the largest gaps between their wanted and actual fertility rates. The highest level of unmet need (at 11 percent) of women aged 15–49 is found in the South-South region, which, according to the authors, also has the highest proportion of young unmarried women who are sexually active. This finding is of particular interest because the proportion of births that are identified as unwanted jumped from 3 percent in 1990 to 19 percent in 2003 for this region. Interestingly, in the South-South region, young women are better educated and marry at later ages than women living in other regions of the country (AGI 2005).

As for the factors associated with induced abortion among young women in Nigeria, a review of the literature suggests that four categories of variables may function as important correlates: sociodemographic factors, absence of educational and career opportunities, relationship dynamics and social context, and knowledge and practice of contraception. Sociodemographic Factors In Africa, a woman’s age has a significant impact on her likelihood of experiencing an abortion. Young women are more likely than older women to have an abortion (Bankole et al. 1999). Moreover, among young women aged 10–24, adolescents aged 15–19 are more likely to have an abortion than are those aged 20–24 (GSS and Macro International 1999). Okonofua et al. (1996) found that adolescents in Nigeria are at decreased risk of pregnancy but are more likely to resort to abortion. In many African countries, single women are much more likely than married women to terminate a pregnancy (Okonofua et al. 1996; Bankole et al. 1999; Calvès 2002). Although married women may seek to terminate a pregnancy for reasons such as cultural taboos against bearing children spaced too closely together, such motivation appears to be less widespread than the influences affecting single women experiencing an unexpected pregnancy (Renne 1997). Religion and ethnicity may have an impact on the prevalence of abortion; certain religions or ethnicities may be more or less tolerant of adolescent pregnancy and abortion (Rasch et al. 2000; Calvès 2002). The few studies that have examined religion or ethnicity with regard to abortion have not found a significant influence, however (Koster-Oyekan 1998; Calvès 2002). Women living in urban areas may have an increased likelihood of choosing to terminate a pregnancy, because social prohibitions against the procedure in effect in rural environments are not found in urban settings. Okonofua et al. (1996) found that in Nigeria urban women are more likely than rural women to end a pregnancy. Place of residence may also have an impact on a young woman’s access to abortion providers; urban residents often have greater access (Rasch et al. 2000; Silberschmidt and Rasch 2001). Family structure may affect some of the factors influencing young women who find themselves faced with deciding whether to terminate a pregnancy. Social support may be dependent on the configuration of the family and on its emotional and economic ability to absorb another child into the household (Calvès 2002; Varga 2002). In Nigeria, young people from polygamous families are more likely to be sexually active and to engage

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in risky sexual behaviors (including transactional sex), compared with those from monogamous homes (Okonofua et al. 2003). In interviews with adolescents who had experienced abortion in Nigeria, Adetoro (1991) found that only 13 percent were living with both parents; most were from broken homes and polygamous families. Educational and Career Opportunities In many sub-Saharan African countries, a substantial minority of unmarried women engage in sexual activity (Murray et al. 2005). A young woman’s sexual debut does not always signal a desire to begin childbearing, however. Because many young women do not use a modern method of contraception, unplanned pregnancies are common, and young women are forced to decide whether to terminate a pregnancy. Their future prospects often influence this decision. A study conducted in Yaoundé, Cameroon, found that women who had terminated a pregnancy were more likely than others to be employed and to be single, and had a slightly higher educational level (Calvès 2002). In many African countries, married students are not permitted to enroll in secondary school and unmarried pregnant girls are expelled. Therefore, for a schoolgirl determined to finish her education, an unintended pregnancy is likely to result in an abortion (Renne 1997; Koster-Okeyan 1998; Rasch et al. 2000). Quantitative and qualitative studies conducted in Nigeria support the hypothesis that future prospects often influence the decision to terminate a pregnancy. Renne (1996) found that the primary reason unmarried schoolgirls gave for undergoing an abortion was their desire to finish school. Okonofua et al. (1996) found that better-educated women and professional women were more likely than others to terminate a pregnancy. Koster’s (2003) qualitative study of abortion among the Yoruba in Nigeria found that, among single women attending school, the primary reason reported for deciding to undergo an abortion was that they were still in school or apprenticing; having career plans was the second most common reason reported. Relationship Dynamics and Social Context The prevalence of abortion among unmarried women is also considered to be linked to the type of relationship the woman has with her sexual partner. For example, pregnancies that result from casual or unwelcome sex or that are discovered after a relationship has ended are reported to have a higher probability of being terminated by induced abortion than other pregnancies in a number of African countries (Rasch et al. 2000; Henry and

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Fayorsey 2002). Young African women frequently become involved with wealthy older partners whom they view as more attractive spouses than men their own age. Qualitative research has determined that when a pregnancy occurs in these relationships, the men, who are often already married, generally refuse to take responsibility for the pregnancy or may pressure the young woman to terminate it. Young women involved in such relationships, therefore, may feel greater pressure than those in other sorts of relationships to have an abortion (Gorgen et al. 1998; Silberschmidt and Rasch 2001). The negative repercussions of social stigma are also likely to influence a young woman’s desire to terminate a pregnancy (Koster-Oyokan 1998; Varga 2002). For example, married women of certain cultural origins may feel obliged to terminate a pregnancy that does not conform to community birth-spacing expectations (Renne 1997; Koster 2003). Knowledge and Practice of Contraception Another factor related to a woman’s risk of pregnancy and likelihood of abortion is her knowledge of contraceptive methods. Studies conducted in Kenya and Nigeria have concluded that level of contraceptive knowledge is directly associated with the number of women who decide to terminate a pregnancy. As the level of knowledge of modern contraception increases, the number of women relying on abortion declines (Araoye and Fakeye 1998; Mpangile et al. 1993). Okonofua and his colleagues (1996) found, however, that women who had knowledge of family planning and of the fertile period were more likely to terminate a pregnancy. Qualitative research in Nigeria has determined that a large proportion of young women are misinformed about modern contraception. Many young women believe that using a modern contraceptive will result in infertility and that abortion is a safe alternative (Barker and Rich 1992; Otoide et al. 2001). Once a young woman has borne a child, her likelihood of practicing contraception has been shown to increase, indicating that she received accurate information about modern contraception after her first child was born (Garenne 2000). Even when young women are correctly informed about contraception and the risks of illegal induced abortion, they may not have ready access to contraceptive methods and may resort to pregnancy termination instead. In many African countries, young unmarried women are unable to obtain modern contraceptive methods at public health service-delivery sites; they perceive contraceptive services to be intended for married women only or for prostitutes (Mpangile et al. 1993; Koster-

Okeyan 1998; Rasch et al. 2000; Silberschmidt and Rasch 2001). Qualitative research conducted with Nigerian adolescents suggests they are aware that they can obtain contraceptives in pharmacies and from patent-medicine vendors, but they are reluctant to do so because they believe that contraceptives have harmful side effects. Qualitative research in Ghana has shown that some young women who attempt to practice contraception do not always practice it effectively (Mpangile et al. 1993; Henry and Fayorsey 2002).

Data and Methods With funding from the POLICY Project to examine a number of adolescent reproductive health issues, WHARC conducted a household survey in urban and rural parts of Edo State in May and June of 2002. The survey targeted 2,100 people aged 10–24, drawing on estimates of the total population of adolescents, of the proportions living in rural and urban areas, and of the proportion of those who were likely to refuse to participate in the study. Although 60 percent of Edo State is rural, WHARC decided to sample the two areas equally because of the large rural-to-urban migration that has occurred in recent years, especially among adolescents. Multistage random sampling was used to identify adolescents to participate in the study. Edo State is divided into three senatorial districts (Edo South, Edo Central, and Edo North) and 18 local government councils (seven in Edo South, five in Edo Central, and six in Edo North). To cover the entire state, WHARC selected study sites from all three senatorial areas; urban and rural areas were sampled separately within each senatorial zone. Thus, urban and rural local government areas (LGAs) were identified within each senatorial zone; one rural LGA and one urban LGA were randomly selected from each zone using a table of random numbers. The distinction between urban and rural LGAs was based on the level of infrastructural development in the area. Maps of the randomly selected LGAs were obtained from the National Population Commission, and all streets within each selected urban area were enumerated. Using a table of random numbers, three streets were randomly selected from the urban LGAs. The selected streets were visited individually, and the households (defined as the number of standing buildings in the streets) were mapped. Because WHARC anticipated finding one to two eligible adolescents per household, the sampling frame was determined from the number of households in each street from which the households to be visited were identified.

By contrast with the urban LGAs, the rural LGAs consist of small villages and hamlets without clearly defined streets. Such rural settlements typically contain between 50 and 100 households. Thus, to select rural LGAs, WHARC enumerated all villages and hamlets using maps prepared by the National Population Commission. WHARC randomly selected five villages per LGA using a table of random numbers. All eligible young adults in each selected village were included in the study. In the survey, WHARC sought to interview 2,100 young adults—700 per senatorial district, of which 350 would come from rural LGAs and 350 from urban LGAs. The LGAs randomly chosen were Orhionmwon and Oredo (from Edo South), Esan South-East and Esan West (from Edo Central), and Etsako East and Etsako West (from Edo North). For the household survey, a questionnaire was designed by a technical working group that attempted to capture all issues that relate to the reproductive health of young adults in the state. The questionnaire was divided into seven sections: (1) sociodemographic characteristics of respondents; (2) patterns of sexual activity; (3) experience of pregnancy, contraception, and abortion; (4) sexually transmitted infections, including HIV/AIDS; (5) sexual violence, female trafficking, and female genital cutting; (6) recreational drug use; and (7) reproductive health-seeking behavior. The technical working group that designed the questionnaire included a number of young people, and the questionnaire underwent pilot testing before it was used. The questionnaires were administered by young interviewers who received one week of training concerning the purposes of the study, sampling techniques, methods for reaching young adults, components of the questionnaire, and ways of eliciting correct and accurate responses. Interviewers asked female respondents the following questions: “Have you ever been pregnant?” “How many of your pregnancies were planned/unplanned?” and “For each pregnancy, what was the outcome?” The response categories for pregnancy outcome listed induced abortion separately from spontaneous abortion (or miscarriage). All data presented in this study refer to responses concerning induced abortion rather than spontaneous abortion. Upon completion of the training, interviewers conducted the survey in the evenings and on weekends, times when they were most likely to find adolescents at home. Interviewers worked in male–female pairs in the sampled areas; male interviewers surveyed male adolescents, and female interviewers questioned female adolescents. Interviewers revisited the homes of adolescents chosen for the sample who were not found at home at

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the time of the first visit until those selected were finally contacted and interviewed. Only adolescents whose parents gave permission for their children’s participation in the study were interviewed. Additional consent was sought from the individual adolescents at the time of interview. Adolescents and their parents were assured of the confidentiality of the information obtained during the study, and the names of respondents did not appear on the questionnaire. Two thousand young people aged 10–24 were selected to be interviewed in the three senatorial districts of the state, and 1,867 respondents completed interviews (a 93 percent response rate); 133 (7 percent) of those selected refused to be interviewed. The respondents included 576 young people (31 percent) in Edo South senatorial district, 567 (30 percent) in Edo Central, and 724 (39 percent) in Edo North. In each senatorial district, interviews were conducted in both rural and urban areas. In all, 1,000 interviews (54 percent) were conducted with young people living in rural areas and 867 (46 percent) were conducted with urban residents. Table 1 provides a description, the gender composition, and the sample sizes of each phase of the analysis. Of the survey respondents, 1,039 (56 percent) were boys and 828 (44 percent) were girls. None of the girls aged 10–14 reported ever having been pregnant. Therefore, the analyses in this study include only data for women aged 15–24. Of the original sample of 828 young women, the maximum sample size is 602 for the analyses presented here.

Analytical Model Our analytical model for understanding abortion among young women in Nigeria is based on the premise that the decision to terminate a pregnancy is the end decision in a cascading series of events. The life events that lead to the decision to terminate a pregnancy are shown in Figure 1. First, a woman experiences sexual initiation. Second, she may become pregnant, either as the result of conscious decision, by accident, or because she lacks access to or knowledge of a means to prevent pregnancy. Finally, assuming that she does not miscarry, she decides whether to bear the child. Each of these events or decisions is affected by a separate but overlapping set of influences. This investigation attempts to determine the relative effect of the various factors that influence each of these events or decisions and to shed light on those factors that can be addressed by public health program or policy interventions. We conducted three sets of analyses using three subsamples of the original sample. The first analysis focuses on factors relating to sexual initiation and includes all 602 female respondents aged 15–24. Our analysis of the determinants of pregnancy includes the 426 female respondents aged 15–24 who have ever had sex. The third analysis concerning characteristics associated with abortion includes the 195 female respondents aged 15– 24 who have ever been pregnant.

Figure 1 2002

Events leading to abortion, Edo State, Nigeria,

Table 1 Sample description, size, and gender composition for each level of analysis, Edo State, Nigeria, 2002 Sample

Description

Original

All male and female respondents aged 10–24

15–24-year-olds

Model I: Ever had sex

Model II: Ever been pregnant

Model III: Ever had an abortion

Ever had an abortion (final event of interest) (N)

All male and female respondents aged 15–24 All female respondents aged 15–24 All female respondents aged 15–24 who reported ever having had sexual intercourse

Female (N)

(1,039)

(828)

(737)

(602)

—

(602)

—

(N = 602)

Model I Sexually active

Not sexually active

68.4 percent (n = 426) (weighted n = 412)


Model II Have been pregnant

Have not been pregnant



Model III —

(195)

All female respondents aged 15–24 who reported ever having had an abortion

—

(116)


Young women aged 15–24

(426)

All female respondents aged 15–24 who reported ever having been pregnant

— = Not applicable.

256

Male (N)

Have had an abortion

Have not had an abortion



Note: Percentages in this figure have been weighted to the urban–rural distribution of 15–24-year-olds in the South-South region of Nigeria found in the 2003 Nigeria Demographic and Health Survey.

Our principal interest here concerns those factors that determine whether a young woman will have an induced abortion. Because she must first have experienced sexual intercourse and become pregnant, we explore factors that we expected to be associated with sexual experience and pregnancy as well as with induced abortion. We estimate a series of probit equations and compare the differing effects of our selected covariates on the possible outcomes. Our estimation strategy is a series of three binarychoice equations: (1) to have had sex or not; (2) to have become pregnant or not; and (3) to have had an induced abortion or not. Each of these equations is estimated using a separate probit model, where

Yt* = xi b + e i ; e ~ N (0, s 2 ); Yt = 0 if Yi* £ A; and Yt = 1 if Yi* > A In this model, Yt* is a latent variable with an observed outcome Yt , and xi is a set of explanatory variables. In Model I, Yt = 1 if a woman has ever had sex and zero if she has not. In Model II, Yt = 1 if a woman has ever been pregnant and zero if she has ever had sex but has never been pregnant. In Model III, Yt = 1 if a woman has ever had an induced abortion and zero if she has ever been pregnant but has never had an induced abortion. A potentially confounding issue in the estimation of the determinants of having an abortion is sample selectivity. Observing whether women who have not yet had sex would be more likely to become pregnant than those who have had sex or whether women who have not yet become pregnant might be more likely to have an abortion than those who have been pregnant is not possible. Women who have not had sex, however, might be more or less likely to become pregnant than those who have had sex; similarly, women who have become pregnant might be more or less likely than those who have not to have an abortion. As examples, those young women who choose not to have sex may have a stronger moral prohibition against both premarital sex and abortion, or they may have a greater desire to avoid having children at this stage in their life and, thus, may be more predisposed to have an abortion if they engaged in sex and became pregnant. Because of these sample-selectivity issues, corrections have been made to Model II (the ever-pregnant equation) and Model III (the ever-had-an-abortion equation) in the manner suggested by Maddala (1990) who builds on the work of Heckman (1974). Maddala suggests estimating the following probit equation:

Yt * = xi b + s

f(Z) + Vi , F( Z )

where Z is the estimated value of a probit equation for whether a woman has ever had sex or ever been pregnant for Models II and III, respectively.2 If the coefficient s is statistically significant, sample-selectivity bias is shown to be operating in the equation. If s is positive in the ever-pregnant equation, women who have had sex are more likely to be predisposed to become pregnant than those who have not yet had sex. Similarly, if s is positive in the ever-had-an-abortion equation, women who have ever been pregnant are more likely than those who have not to be predisposed to have an abortion. Specification of Covariates Based on our review of the literature, and limited by the data available to us from the 2002 Edo State survey, we selected a number of variables that we expected to be associated with a young woman’s decision about whether to terminate a pregnancy: sociodemographic factors, life opportunities, relationship dynamics and social context, and contraceptive use. Unfortunately, the data for these variables were not collected at the time of the reported pregnancy terminations. Some of the variables can be assumed to have remained constant over time. For other variables, we use proxies that precede temporally the outcome event specified. When this was not possible, as in the case of school-enrollment status, we had to exclude the variable from our multivariate analyses. Sociodemographic Factors Sociodemographic variables such as respondents’ age, residence, ethnicity, religion, and marital status are included. Additional variables concerning family structure include whether the respondent’s father is polygamous and whether the respondent’s parents are still living together. We also calculate some exposure variables to control for differing ages at sexual debut for the pregnancy and abortion outcomes and for the total number of pregnancies a woman reported for the abortion model. Although we include marital status in our analysis, the interpretation of this variable needs to be made cautiously, because our measure of marital status was reported at the time of the interview and may not be indicative of marital status at the time of pregnancy termination. Life Opportunities Measures of socioeconomic status of the household include: an index measure of material possession and access to services,3 and parental education (whether either parent has had formal schooling). Although we have information about the respondents’ school-enrollment status at the time of the interview, and we examined the ef-

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fects of school enrollment in both our bivariate and initial multivariate models, we decided that the endogeneity of this variable was too great to include it in our final multivariate models.4 Unfortunately, we have no information on respondent’s in-school status at the time of pregnancy. Relationship Dynamics and Social Context Although we know the nature of the relationship that respondents have with their current sexual partners, our data do not specify the respondents’ age at the time of induced abortion, nor whether the current sexual partner was the one responsible for the pregnancy that was terminated. For this study, we use the type of relationship between the respondent and her first sexual partner to characterize the kind of sexual relationship she had prior to pregnancy and/or abortion. Obviously, the woman’s first sexual partner may not have been the individual responsible for reported pregnancies or terminations in all cases, but we prefer to rely on a variable that clearly precedes the event(s) of interest. To capture the relationship dynamic of girls in partnerships with older men, we use the age difference between the respondent (at first sex) and her partner (at first sex), although we cannot be certain that this variable will represent the age difference between the respondent and her partner at the time she terminated her pregnancy. Initially, we included two other variables to capture different dimensions of the relationship between respondents and their sexual partners: whether the respondent had ever experienced forced sex and whether the respondent had ever exchanged sex for gifts or money. In the exploratory analyses of the data, we found that most of the women responding “yes” to these two questions were the same individuals, so we combined the two questions. We suspect that these variables capture some dimension of risky behavior and the power dynamics of (and commitment to) the relationship. In the model for having experienced sexual intercourse, we use age at first use of alcohol to capture an underlying willingness to take risks. Unfortunately, our data do not include information for measuring social stigma directly or information concerning whether the young women surveyed were pressured or coerced into having an abortion by parents, friends, or partners. Knowledge of, Attitudes Toward, and Practice of Contraception Although we have information on respondents’ use of contraceptives at the time of interview, ultimately we decided to use a variable that we are certain precedes the respondents’ pregnancy and abortion, among those who

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have experienced those events—namely, use of a contraceptive at first intercourse. This variable captures respondents’ access to contraception directly and provides an indirect measure of their motivation to avoid pregnancy. Finally, Nigeria-specific data suggest that misperceptions about the side effects of contraception result in young women’s overreliance on abortion (Otoide et al. 2001). Ideally, we would have been able to use a good measure of young women’s perceptions of contraception preceding their pregnancy and abortion experiences. The reported use of a family planning method at first sex may capture part of this dimension.

Results The results that follow include descriptive statistics, findings of the prevalence of induced abortion among young women aged 15–24 in Edo State, bivariate analyses, and a series of multivariate probit models that examine the relative importance of each of the factors related to induced abortion while controlling for other significant influences. Descriptive Statistics Table 2 shows selected sociodemographic characteristics of the 15–24-year-old females in the survey sample. The predominant ethnic groups are the Ishan and Etsako, followed by the Bini. Most respondents identify themselves as Christian, and less than 8 percent say they are Muslim. The overwhelming majority (88 percent) are not married. About two-thirds of all respondents are enrolled in school; this large proportion is probably the result of delayed entry and grade repetition, a common pattern in Africa (Lloyd et al. 2000; Lloyd and Hewett 2003). An interesting feature of this population is the high level of polygamy reported, although the Muslim population is relatively small. The fathers of half the girls interviewed have more than one wife. Given the policy and program implications of our research, we sought to validate our sample with similar subsets from the 2003 NDHS to see how our female respondents compare on key characteristics. We looked at age distribution, marital status, and school-enrollment status for women aged 15–24 in the 2003 NDHS, South-South region. Our Edo State sample is virtually identical to that of the NDHS South-South sample: 57 percent of the WHARC sample of young women are aged 15–19, compared with 58 percent of the NDHS sample; 43 percent of the WHARC sample are aged 20–24, the same propor-

Table 2 Percentage distribution of young women surveyed aged 15–24, by selected weighted sociodemographic characteristics, Edo State, Nigeria, 2002 Characteristic

Percent

Age 15–19 20–24 Total (N)

57.0 43.0 (602)

Ethnicity Ishan Etsako Bini Igbo Other Total (N)

32.9 28.1 18.3 5.7 15.0 (602)

Religion Pentecostal Catholic Protestant Muslim Traditional Other a Missing (n) Total (n)

39.0 35.1 14.9 6.2 3.8 1.1 (4) (598)

Marital status Single Married Divorced/separated Widowed Total (N)

87.8 12.0 0.2 0.0 (602)

School-enrollment status In school Missing (n) Total (n)

62.0 (3) (599)

Type of household Monogamous Polygamous Missing (n) Total (n)

50.5 49.6 (3) (599)

a Includes Eckankar, Jehovah’s Witness, and Celestial. Notes: Data in this table have been weighted to the 2003 Nigeria Demographic and Health Survey urban–rural distribution of 15–24-year-olds, South-South region.

Prevalence of Induced Abortion Among the 602 female respondents aged 15–24 surveyed, adjusting for the underrepresentation of ever-married women, we find that 41 percent of reported pregnancies were terminated by means of induced abortion (see Tables 3a and 3b). We calculate the age-specific abortion rate for the 15–19-year-olds in this survey sample at an estimated 49 procedures per 1,000 women (see Tables 3c and 3d), nearly double the national estimate of 25 abortions per 1,000 women calculated by Henshaw and his colleagues in 1998, but only slightly higher than their estimate of 46 abortions per 1,000 women for the Southwest region and considerably higher than their estimate for the Southeast region of 32 procedures per 1,000 women. Our data confirm that induced abortion is highly prevalent among the young women of Edo State, Nigeria. Bivariate Analyses Table 4 presents profiles of respondents disaggregated by whether they have experienced sexual debut, been pregnant, or have had an abortion. The proportions of

Table 3a Number of pregnancies reported by female respondents aged 15–24, Edo State, Nigeria, 2002 Number of pregnancies 1 2 3 4 5 6 7 8 Missing information Total

Respondents

Total pregnancies

96 61 24 5 2 0 2 1 4 195

96 122 72 20 10 0 14 8 na 342

na = Not available.

tion as that of the NDHS sample. The Edo State sample differs substantially from the South-South NDHS sample with regard to marital status. Nearly 90 percent of the Edo State females are single, compared with just 79 percent of the NDHS sample. Finally, a higher proportion of the Edo State young women are still in school (62 percent), compared with 54 percent of the NDHS sample. The relatively large differences in distribution for marital status and school-enrollment status between the Edo State sample and the NDHS sample may not reflect biases in the Edo State sample. The greater proportion of young women who are single in Edo State could reflect the state’s higher levels of school enrollment. This difference should be kept in mind when interpreting our findings.

Table 3b Number of abortions reported by female respondents aged 15–24, Edo State, Nigeria, 2002 Number of abortions 1 2 3 4 5 6 7 8 Total

Respondents

Total abortions

79 28 4 1 2 0 1 1 116

79 56 12 4 10 0 7 8 176

Percent of pregnancies terminated Percent of pregnancies terminated (weighted) a

51.5 40.7

a

Results weighted by the distribution of ever-married women aged 15–24 surveyed in the 2003 NDHS, South-South region.

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Table 3c Number of abortions reported by female respondents aged 15–19, Edo State, Nigeria, 2002 Number of abortions

Respondents

Total abortions

22 5 1 28

22 10 8 40

1 2 8 Total

Table 3d Age-specific abortion rate for female respondents aged 15–19, by age at interview, according to average years of exposure to risk of abortion and person-years of exposure in interval, Edo State, Nigeria, 2002 Respondent’s age at interview (years) 15 16 17 18 19 15–19 Total number of abortions/ total person-years in intervala

Respondents

Average years of exposure to risk of abortion per person

Total personyears of exposure in interval

74 63 46 71 70

0.5 1.5 2.5 3.5 4.5

37.0 94.5 115.0 248.5 315.0 810.0 0.0494

a

Information about age at pregnancy is available, but information about age at abortion is not. Assuming that no abortions were performed for respondents younger than 15, we can calculate an age-specific abortion rate for 15–19-yearolds. This rate cannot be calculated for 20–24-year-olds.

women who have ever experienced the outcomes of interest are presented by the categories of the covariates used subsequently in the multivariate probit models. Sexual Debut In Model I, describing whether the respondent reports having experienced sexual debut, we see that nearly all (94 percent) of the 20–24-year-olds have had sex and that more than half (51 percent) of the 15–19-year-olds report the same. Young women living in urban areas are more likely to report having had sex; roughly three-fourths of them responded affirmatively, compared with twothirds of respondents residing in rural areas. No significant differences are seen in sexual debut according to the primary types of ethnic groups found in Edo State, nor are differences found by religion. Interestingly, three-fourths of young women from polygamous families report being sexually experienced, compared with two-thirds of young women from nonpolygamous families. Also, as has been shown in many studies, young women who are currently in school are less likely than young women not enrolled in school to report having experienced sexual debut; 60 percent and 87 percent, respectively, ever reported having had sex. As expected, nearly all young ever-married women have had their first sexual experience (97 percent), com-

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pared with slightly more than two-thirds of single young women. Surprisingly, neither mother’s education, father’s education, nor household economic status appears to be associated with young women’s likelihood of being sexually active, although whether respondents’ parents live together is significantly associated with whether the respondents have ever had sex. Of those women whose parents are not living together, more than fourfifths have had sex, compared with two-thirds of those women whose parents live together. Finally, 80 percent of young women who report having consumed alcohol before age 16 report having had sex,5 compared with 70 percent of those who did not try alcohol before they were 16, but this difference is not statistically significant. Pregnancy Model II presents data concerning whether sexually active respondents report ever having been pregnant. Sixty percent of 20–24-year-olds report having been pregnant at least once, compared with only one-fourth of the 15– 19-year-olds in the sample. Young women living in urban areas are also more likely to report having been pregnant; more than half report at least one pregnancy, compared with less than 40 percent of respondents residing in rural areas. Both ethnicity and religion are associated with pregnancy. Only slightly more than one-third of Etsako respondents report having been pregnant, compared with more than 50 percent of Bini, Igbo, Delta, and other ethnicities. Similarly, only 43 percent of Christian women report having been pregnant, compared with nearly 60 percent of Muslims and 80 percent of those of traditional and other religions. Whether a young woman comes from a polygamous household makes no difference in whether she is likely to have been pregnant, although women whose parents are still living together are significantly less likely to have been pregnant than are those whose parents are not still together (40 percent versus 55 percent). As expected, ever-married women are significantly more likely to report having experienced a pregnancy (95 percent) than are those who are single (36 percent). Their parents’ education appears to be important in relation to respondents’ likelihood of having been pregnant. Approximately 40 percent of women whose mother or father had completed formal schooling have been pregnant, compared with more than 50 percent of those whose parents had partial or no schooling. Socioeconomic status of the household is not significantly associated with the respondents’ pregnancy history. Fifty-nine percent of young women who report having consumed

Table 4 Percentage of female respondents aged 15–24 who reported having experienced sexual debut, pregnancy, and induced abortion, by selected sociodemographic and other characteristics, Edo State, Nigeria, 2002 Model I Characteristic Sample for model (N)

Model II

Ever had sex

Model III

Ever been pregnant

Ever had an abortion

All women aged 15–24 (602) *** 51.2 (324) 93.5 (277)

All women aged 15–24 who have ever had sex (426) *** 24.7 (166) 59.5 (259)

All women aged 15–24 who have ever been pregnant (195)

Residence Urban Rural

** 75.8 (302) 65.6 (299)

* 51.5 (229) 39.3 (196)

* 65.3 (118) 50.6 (77)

Ethnicity Bini Etsako Ishan Othera

68.2 71.5 67.7 76.1

(110) (151) (198) (142)

* 54.7 (75) 36.1 (108) 44.0 (134) 51.9 (108)

56.1 53.8 64.4 60.7

Religion Traditional, other Christianb Muslim

57.7 (26) 71.1 (526) 73.5 (49)

** 80.0 (15) 43.3 (374) 58.3 (36)

* 66.7 (12) 62.3 (162) 33.3 (21)

Father polygamous No Yes

** 65.9 (320) 76.2 (281)

46.4 (211) 45.3 (214)

63.3 (98) 55.7 (97)

School-enrollment status In school Not in school

*** 60.2 (369) 87.4 (230)

*** 28.4 (222) 65.2 (201)

*** 88.9 (63) 45.8 (131)

Marital status Unmarried Married, divorced, or separated

*** 66.9 (525) 97.4 (76)

*** 35.6 (351) 94.6 (74)

*** 84.0 (125) 15.7 (70)

Mother’s education Has not completed school Has completed school

69.7 (208) 71.2 (393)

* 53.8 (145) 41.8 (280)

** 47.4 (78) 67.5 (117)

Father’s education Has not completed school Has completed school

70.6 (153) 70.8 (448)

* 54.6 (108) 42.9 (317)

54.2 (59) 61.8 (136)

Household socioeconomic status Low Medium-high

69.3 (375) 73.0 (226)

45.0 (260) 47.3 (165)

62.4 (117) 55.1 (78)

Parents living together No Yes

*** 81.2 (197) 65.6 (404)

** 55.0 (160) 40.4 (265)

58.0 (88) 60.7 (107)

Used alcohol prior to age 16 No Yes

69.5 (528) 79.5 (73)

* 43.9 (367) 58.6 (58)

58.4 (161) 64.7 (34)

Relationship to first sexual partner Spouse/boyfriend Other

na na

*** 46.3 (382) 42.5 (40)

59.3 (177) 64.7 (17)

Age difference between respondent and first sexual partner Partner younger or 0–5 years older Partner 6+ years older

na na

*** 36.8 (239) 67.0 (103)

71.6 50.7

Received gifts/money for sex or suffered forced sex No Yes

na na

*** 35.1 (168) 52.9 (257)

** 45.8 (59) 65.4 (136)

Used a contraceptive at first sex No Yes

na na

48.5 (309) 38.8 (116)

* 54.7 (150) 66.3 (45)

Years since sexual debut 1 or less 2–5 6–10 10+

na na na na

*** 16.8 (101) 47.1 (240) 80.6 (67) 83.3 (6)

70.6 (17) 61.1 (113) 55.6 (54) 60.0 (5)

Number of children 0 1+

na na

na na

*** 93.5 (107) 18.2 (88)

Number of pregnancies 0 1 1+

na na na

na na na

*** — 66.0 (97) 53.1 (98)

Age 15–19 20–24

68.3 (41) 57.1 (154)

(41) (39) (59) (56)

** (88) (69)

*Significant at p£0.05; **p£0.01; ***p£0.001. na = Not available. — = Not applicable. b Includes Akoko-Edo, Delta, Hausa, Igbo, Owan, and Yoruba. Includes Catholic, Pentecostal, and Protestant. Note: Some totals do not sum to entire sample size because of missing values. a

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alcohol before age 16 also report having been pregnant, compared with 44 percent of those who say they had not tried alcohol before age 16; this difference is statistically significant. Most women who have been pregnant report that their first sexual partner was either their spouse or a boyfriend, and those who say that their first sexual partner was a boyfriend or spouse are significantly more likely to have been pregnant. Of those women whose first sexual partner was more than five years older than they were, 67 percent have been pregnant, compared with 37 percent of those women whose first sexual partner was the same age or within five years of their own age. More than 80 percent of women who report that their sexual debut was more than five years before the interview have been pregnant, compared with 17 percent and 47 percent of those women who experienced sexual debut a year or less or two to five years before the interview, respectively. Abortion In the third model, 68 percent of 15–19-year-olds report having had at least one abortion, compared with 57 percent of 20–24-year-olds in the ever-pregnant sample. This difference between the two age groups is not statistically significant, perhaps because of the relatively small sample size. Urban residence is associated with ever having had an abortion; two-thirds of urban respondents report having had an abortion, compared with just half of the respondents living in rural areas. Religion is associated with ever having had an abortion; only one-third of Muslim respondents report ever having had an abortion, compared with approximately two-thirds of respondents in all other religious groups. Neither ethnicity, nor whether the respondent comes from a polygamous household, nor whether the respondent’s parents are still living together is significantly associated with ever having had an abortion. In our bivariate analyses, a large difference is found between the proportions of unmarried versus married respondents who report ever having had an abortion. Approximately 84 percent of unmarried females report terminating a pregnancy, compared with only 16 percent of ever-married respondents. In-school status is also associated with ever having had an abortion; almost 90 percent of respondents still in school report having had an abortion, compared with less than half of those not in school. Maternal education is also associated with ever having had an abortion; two-thirds of respondents whose mothers had completed school have had an abortion, compared with less than 50 percent of those whose moth-

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ers had not completed school. Paternal education and socioeconomic status of the household are not significantly associated with ever having had an abortion. Having consumed alcohol prior to age 16 is not significantly associated with ever having had an abortion. Some variables related to the nature of respondents’ early sexual partners are associated with ever having an abortion, however, such as the respondent’s relationship with her first sexual partner. As expected, a higher proportion of respondents whose first sexual partner was not a spouse or boyfriend report ever having had an abortion. Unexpectedly, more than 70 percent of women whose first sexual partner was of a similar age report having had an abortion, compared with only half of respondents whose first partner was more than six years older, perhaps reflecting a greater likelihood that agedisparate partners are married. Two-thirds of respondents who report having exchanged sex for money or having experienced forced sex report having had an abortion, compared with 46 percent of those who have not experienced transactional or coercive sex. Additionally, two-thirds of respondents reporting use of a contraceptive at first sex report ever having had an abortion, compared with slightly more than half of the respondents who did not use a contraceptive at first sex. This finding suggests that those respondents motivated to use a contraceptive at first sex will resort to abortion in the event of contraceptive failure. Surprisingly, the number of years since sexual debut is not significantly associated with ever having had an abortion. Number of pregnancies, however, is significantly associated with ever having an abortion; two-thirds of respondents who report having had only one pregnancy have had an abortion, compared with 53 percent of respondents who report having been pregnant more than once. More than 90 percent of respondents without children report ever having had an abortion, compared with less than 20 percent of respondents with children.

Multivariate Analyses Results from the probit analyses are presented in Table 5. The estimated coefficients produced are not readily interpreted by intuition. A recommended mode of presentation, which we have adopted, is to transform the probit coefficient into the estimated effect of a unit change in the covariate on the probability of the event (evaluated at the sample mean). Because all of the covariates are dichotomous variables, the probabilities presented represent the likelihood of the event for this subgroup of the population in comparison with the reference group

Table 5 Multivariate probit models, with and without sample-selection corrections, of estimated change in probability among women aged 15–24 having experienced sexual debut, pregnancy, and induced abortion, by selected sociodemographic and other characteristics, Edo State, Nigeria, 2002 Model I: Ever had sex

Characteristic Sample-selectivity bias

(n = 602)

Model II: Ever been pregnant Uncorrected sample (n = 426)

Model III: Ever had an abortion

Corrected sample (n = 426)

Uncorrected sample (n = 195)

Corrected sample (n = 195)

—

—

0.59

—

1.38

Age 15–19 (r) 20–24

0.00 0.37**

0.00 0.17*

0.00 0.27

0.00 –0.10

0.00 0.09

Residence Rural (r) Urban

0.00 0.08

0.00 0.13

0.00 0.16*

0.00 0.12

0.00 0.18

Ethnicity Bini (r) Etsako Ishan Other a

0.00 0.10 0.05 0.09

0.00 –0.27** –0.10 –0.11

0.00 –0.25* –0.09 –0.09

0.00 0.12 0.03 –0.02

0.00 0.04 0.04 0.00

0.00 –0.10 –0.21

0.00 0.15 0.16

0.00 0.13 0.14

0.00 –0.17 0.23

0.00 –0.11 0.26

0.00 –0.04

0.00 –0.02

0.00 0.00

0.00 –0.03

Religion Christian b (r) Muslim Traditional, other Father polygamous No (r) Yes

0.00 0.10**

Marital status Never married (r) Ever married

0.00 0.21**

Parents living together No (r) Yes Years since sexual debut 1 or less (r) 2–5 6+

0.00 –0.11**

0.00 0.59**

0.00 –0.16*

0.00 –0.18*

0.00 –0.76**

0.00 –0.61**

0.00 –0.01

0.00 –0.07

0.00

0.00

na

na

0.00 0.27**

0.00 0.31*

0.00 0.20** 0.43**

0.00 0.20** 0.43**

na na

na na

na na

Parents’ education Neither parent has formal education (r) At least one parent has education

0.00 0.01

0.00 –0.04

0.00 –0.03

0.00 0.07

0.00 0.08

Household-wealth index Lower 60 percent (r) Upper 40 percent

0.00 0.06

0.00 0.03

0.00 0.04

0.00 –0.03

0.00 0.01

Used alcohol prior to age 16 No (r) Yes

0.00 0.12*

0.00 0.09

0.00 0.12

na na

na na

Relationship to first sexual partner Spouse/boyfriend (r) Other

na na

0.00 –0.11

0.00 –0.11

0.00 0.07

0.00 0.07

Received gifts/money for sex or suffered forced sex No (r) Yes

na na

0.00 0.12

0.00 0.20

Used a contraceptive at first sex No (r) Yes

na na

0.00 0.21

0.00 0.20

Number of pregnancies 1 (r) 1+

Pseudo R2 Log-likelihood function

0.00 na na

0.00 0.58**

0.2629 –268.12

0.00 0.21**

0.00 0.21**

0.00 –0.07

0.00 –0.07

0.3308 –196.59

0.3314 –196.42

0.4292 –75.14

0.4425 –73.38

* Significant at p£0.05; **p£0.01. (r) = Reference category. na = Not available. — = Not applicable. a b Includes Akoko-Edo, Delta, Hausa, Igbo, Owan, and Yoruba. Includes Catholic, Pentecostal, and Protestant. Note: Observations with missing values were put in the reference category.

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(Liao 1994). The correct interpretation of the estimates is that holding all else constant at the sample mean, a unit change in the covariate (in this case from one to zero or from zero to one) results in the estimated percentage increase or decrease in the probability of the event.6 We use traditional notation for p-values in Table 5. Because the numbers of ever-pregnant women included in Model III are small, we discuss those factors that result in fairly large increases or decreases in the probability of the event, regardless of the significance level. Model I: Sexual Debut As expected, women aged 20–24 are significantly (37 percent) more likely than 15–19-year-old women to report having had sex. The following findings, although not statistically significant, emerge as quantitatively suggestive: urban women are nearly 10 percent more likely than rural women, and Bini women are approximately 10 percent less likely than women of other ethnicities to report having had their first sexual experience. Likewise, Muslims are 10 percent less likely, and those belonging to a traditional religion are 21 percent less likely than Christians to have had sexual intercourse, although neither difference is statistically significant. Consistent with the findings from the bivariate analyses, women whose fathers have more than one wife are significantly (10 percent) more likely to have experienced sexual debut, compared with those whose fathers have only one wife. As expected, women who are married are significantly more likely than those who are single to be sexually active. This difference increases the probability of sexual debut by 21 percent. Young women reporting that their parents are living together are 11 percent less likely than those whose parents are not to report having experienced sexual intercourse. Neither parental education nor household income is significantly associated with sexual experience. Women who tried alcohol before age 16 are 12 percent more likely to report being sexually experienced than are women who have never tried alcohol or who tried it after they were 16. Model II: Pregnancy For the pregnancy model in Table 5, we report the results of probit estimation with and without the sampleselectivity correction. In this model, the factor for the sample-selectivity-bias correction is not statistically significant and does not have a large material effect on the values of most of the coefficients. The discussion below reports only on the equation with the sample-selectivity correction included.

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Many of the covariates that are important in modeling young Edo State women’s experience of first intercourse are also important contributors to the modeling of their experience with pregnancy. Thus, older women are more likely than younger women to report having been pregnant. Although the difference between women aged 20–24 and those aged 15–19 for this variable is not statistically significant, the difference is quantitatively important; older women are 27 percent more likely than younger women to report having been pregnant. Women living in urban areas are 16 percent more likely than those living in rural areas to report ever having been pregnant, a significant difference. Ethnicity is a partially significant covariate in the ever-pregnant model, but the effects are in the opposite direction from the effects in the ever-had-sex model. Although the Etsako are 10 percent more likely ever to have had sex in comparison with the Bini, the Etsako are 25 percent less likely to have been pregnant. The Ishan and other ethnic groups are 10 percent less likely than the Bini ever to have been pregnant, but this finding is not statistically significant. Similar to the ever-had-sex model, religion is a quantitatively, but not statistically, significant variable, although the effects are in the opposite direction; Muslims and those practicing traditional religion are almost 15 percent more likely to have been pregnant than Christians. Married women are 59 percent more likely than single women to have been pregnant at least once. Respondents whose parents are living together are 18 percent less likely than those whose parents live apart to ever have been pregnant. As in the ever-had-sex model, parental education and household economic status are neither quantitatively nor statistically significant. Those who tried alcohol prior to age 16 are 12 percent more likely to have been pregnant, but this finding is not statistically significant. Not surprisingly, the longer a woman has been sexually active, the more likely that she will have been pregnant. Women who have been sexually active for two to five years are 20 percent more likely to have been pregnant, and women who have been sexually active six years or more are 43 percent more likely to have been pregnant than those who became sexually active in the past year. Respondents whose first sexual partner was not a spouse or boyfriend are 11 percent less likely than those who were in such relationships ever to have been pregnant, but this finding is not statistically significant. Women who have ever been forced to have sex or received money in exchange for sex are 21 percent more likely than other women ever to have been pregnant, a statis-

tically significant finding. Contrary to our expectations and to results of the bivariate analyses, use of a family planning method at first sex is neither quantitatively nor statistically significant. Model III: Abortion As in the pregnancy model, we report the results of the probit estimation model for ever having had an abortion with and without the sample-selectivity correction, and we discuss only the latter. The sample-selectivity correction in the abortion model is statistically significant, suggesting that women who are not yet pregnant but who may become pregnant are less likely to have an abortion than those who are already pregnant. We could speculate that, on average, women who have not become pregnant are not pregnant because they are unwilling to terminate an unintended pregnancy. Surprisingly, in the abortion model, age is not significantly associated with ever having had an abortion, and the difference between the two age groups is not large. Residence is quantitatively suggestive but not statistically significant; urban respondents are 18 percent more likely than those living in rural areas ever to have had an abortion. The differences across ethnic groups are small in this model and not statistically significant. Muslim women are 11 percent less likely and women of traditional religions 26 percent more likely than Christian women ever to have had an abortion, although neither result is statistically significant. The difference between respondents who have a polygamous father and those whose fathers have one wife is minimal and not statistically significant. As expected, married women are significantly less likely (61 percent) than unmarried women ever to have had an abortion. As in the ever-had-sex and ever-pregnant models, parental education and economic status of the household are not significantly associated with ever having had an abortion. In contrast with the ever-hadsex and ever-pregnant models, however, the stability of respondents’ parents’ relationship is not significantly associated with ever having had an abortion. The type of relationship respondents had with their first sexual partner is not statistically or quantitatively significant. Respondents who have been pregnant more than once are 31 percent more likely to report having had an abortion than are those who have been pregnant only once; this finding is statistically significant. Having experienced transactional or forced sex and having used a contraceptive at first sex each correspond with a 20 percent greater likelihood of ever having had an abortion, although neither effect is statistically significant.

Discussion This study analyzes data from a survey conducted by WHARC in 2002 exploring a variety of reproductive health issues among a sample of 1,867 young people aged 10–24 in Edo State, Nigeria, located in the country’s South-South geopolitical region. Our analysis focuses on the prevalence of and factors associated with induced abortion among the survey’s 602 female respondents aged 15–24. For the 15–19-year-olds, we estimate an agespecific abortion rate of 49 procedures per 1,000 women, which is almost double the rate found by Henshaw and colleagues (1998; using a different method of data collection) for all of Nigeria, and somewhat higher than the rates of 46 and 32 abortions per 1,000 women that these researchers found in Nigeria’s Southwest and Southeast health zones, respectively. Our findings of high levels of induced abortion among young Nigerian women interviewed for this study provide justification for continued attention to and study of this public health issue, and underscore the centrality of adolescents among those seeking pregnancy termination in southern Nigeria. Our study uses information available from the survey to devise explanatory multivariate models for analyzing the factors associated with each of three critical steps along the path toward induced abortion—onset of sexual intercourse, becoming pregnant, and terminating the pregnancy—controlling for important demographic and risk-behavior factors. Because the WHARC survey was not designed as an in-depth study of abortion, the data imposes limitations on our effort to develop a profile of young women who might be likely to terminate a pregnancy. For example, the sample is small and contains a disproportionate number of never-married women for this age group, and the information gathered characterizes respondents at the time of the survey rather than at the time of sexual initiation, of becoming pregnant, or of terminating a pregnancy. Our efforts to address these limitations include correcting for sample selectivity, discarding our in-school-status variable from the multivariate analyses, and qualifying our conclusions regarding the marital status variable. Across the three models, the findings meet expectations for two sets of key variables. First, ever-married women are more likely to have had sex, been pregnant, and carried all of their pregnancies to term. These results imply that concerning the decision to terminate a pregnancy, women who are married when they become pregnant may be less likely to rely on abortion as a means of birth control or as a backup in the event of contraceptive failure. This interpretation must be made cautiously, however, because some of the women who were

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married at the time of the interview and who report having terminated a pregnancy may have undergone the procedure when they were single. Second, the exposure variables are significant in each of the models. As expected, in the ever-had-sex model, older women are significantly more likely ever to have had sex. In the ever-pregnant model, women who have been sexually active for two to five years before the interview are more likely ever to have been pregnant than are women who have been sexually active for less than two years, and women who have been sexually active for more than six years are more likely ever to have been pregnant than are women who have been sexually active for two to five years. In the abortion model, women who have been pregnant more than once are more likely ever to have had an abortion than are those who have been pregnant only once. In policy and program terms, therefore, efforts to reduce the number of unintended pregnancies by increasing effective contraceptive use will result in fewer pregnancies and abortions. Family structure is found to be an important determinant of sexual initiation and pregnancy. Young women whose parents still live together are less likely to have become sexually active, and those who are sexually active are less likely to have become pregnant. Young women whose fathers have more than one wife are more likely to have experienced sexual debut. On the other hand, these variables do not have a direct statistically significant effect on ever having had an abortion, possibly because of the small sample size. The programmatic implications here are mainly that behavioral change messages and information should be aimed at girls (and their parents) whose parents are not living together or whose fathers are polygamous, because these girls are at greater risk than other girls of advancing through some of the stages of the model. Relationship dynamics and risky sexual behavior variables (including drinking and certain types of sexual relationships) are found to be important in all three models. Drinking before age 16 is a statistically significant predictor of having had sex and has a quantitatively suggestive influence on ever becoming pregnant. Similarly, a respondent who ever received money in exchange for sex or suffered forced sex is 20 percent more likely to have become pregnant and, if pregnant, 20 percent more likely to have had an abortion than those who have not. These results suggest that behavioral change messages aimed at reducing the incidence of risky behavior among adolescents, such as alcohol consumption, if successful, will lead to a rise in age at sexual debut and a decrease in the number of pregnancies and abortions. At the same time, programs that aim to increase the empowerment

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of girls to resist sexual advances and to make their own decisions (such as the Girls’ Power Initiative—an NGO program operating in Edo State) are on target. Programs successfully addressing the prevalence of coercive sex should also have important protective effects. Place of residence also is shown to be a significant factor in terms of sexual debut, pregnancy, and abortion. Urban women are somewhat more likely to have become sexually active, are significantly more likely to have ever become pregnant, and are somewhat more likely to have undergone an abortion. This information implies that urban young people could benefit from programs aimed at changing their behavior and providing them with reproductive health care. Religion and ethnicity have ambiguous influences on the three events of interest here. Some evidence from the bivariate and multivariate models shows that Muslim women begin their sex lives earlier than Christian women (perhaps because they marry earlier) but do not resort as frequently as Christians to abortion. Etsako women appear to be more sexually active but better at avoiding pregnancy than women from other groups, perhaps because they have better knowledge of and access to contraceptives. Although limitations of the data necessitated the exclusion of a few important factors from the model and require us to use caution in drawing conclusions, these analyses help to shed light on factors such as the effect of forced and transactional sex, length of sexual activity, and marital status, all of which appear to be critical for addressing the high levels of induced abortion among young women in southern Nigeria.

Notes 1

Whereas Henshaw and his colleagues divide the country into four geographic regions (corresponding to the four health zones defined by the Nigerian government), the DHS sampling frame is based on the six geopolitical regions of the country: North-West, North-Central, North-East, South-West, South-South, and SouthEast.

2

The ever-pregnant equation is estimated only for women who have ever had sex, and the ever-had-an-abortion equation is estimated only for women who have ever been pregnant.

3

Following a commonly employed method, we use a weighted index of asset ownership (Filmer and Pritchett 2001). The weights are based on the scores from a factor analysis of 12 assets.

4

A woman may have left school as a result of becoming pregnant, or she may have remained in school because her pregnancy was terminated. Our initial probit models included the school-enrollment status of respondents at time of the interview (not shown). The coefficient of this variable was always strongly significant in the expected direction (negatively related to ever having had

sex and ever having been pregnant and positively related to having an induced abortion). The inclusion of this variable did not substantially affect the value of any of the other coefficients. 5

This age (16) is younger than the median age at first sex (17) for this sample.

6

The sole exception is the impact of the sample-selectivity correction, which is presented as the marginal impact on the probability caused by a marginal change in the sample-selectivity correction.

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Acknowledgments This work has been supported by the POLICY II Project funded by United States Agency for International Development (USAID). It is implemented by the Futures Group in collaboration with Research Triangle Institute (RTI) and the Centre for Development and Population Activities (CEDPA). Jerome Mafeni, former Country Director for POLICY II and current Director of Constella Futures’ ENHANSE Project in Nigeria, provided invaluable in-country support with the data collection and analysis efforts of WHARC and with our subsequent analysis of induced abortion. We gratefully acknowledge the support and participation of the WHARC staff, the interviewers, and all of the young people who participated in the adolescent reproductive health survey in Edo State, Nigeria.