May 11, 2017 - Exercise as treatment for low back pain during pregnancy . .... intervention used in clinical practice as well as to identify women at risk. The aim .... affected of low back pain a continued professional and scientific awareness is .... views on and attitudes toward pelvic girdle pain among midwives Mogren and.
Low back pain during pregnancy. Prevalence and intervention
PhD Thesis Mette Grønbæk Backhausen
Department of Obstetrics & The Research for Unit Womens’s and Children’s Health, Rigshospitalet and The Department of Obstetrics and Gynaecology, Zealand University Hospital, Roskilde, Denmark May 2017
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Author Mette Grønbæk Backhausen, RM, MSc Department of Obstetrics & The Research Unit for Womens’s and Children’s Health, Rigshospitalet, The Department of Obstetrics and Gynaecology, Zealand University Hospital, Roskilde and the Faculty of Health and Medical Sciences, University of Copenhagen. Supervisors Hanne Kristine Hegaard, Senior researcher, RM, PhD Department of Obstetrics & The Research Unit for Womens’s and Children’s Health, Rigshospitalet. Ann Tabor, Professor, MD, DMSc Department of Obstetrics, The Juliane Marie Centre, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Peter Damm, Professor, MD, DMSc Department of Obstetrics, The Juliane Marie Centre, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
Evaluation Committee Christina Rørbye, Associate Professor, MD, PhD The Department of Obstetrics and Gynaecology, Hvidovre Hospital and University of Copenhagen Per Ovesen, MD, DMSc The Department of Obstetrics and Gynaecology, Aarhus University Hospital, Skejby Per Kristiansson, Senior lecturer, MD, PhD Department of Public Health and Caring Sciences, Family Medicine and Preventive Medicine, Uppsala University, Sweden
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Indhold List of publications ................................................................................................................. 4 Preface and acknowledgements ........................................................................................ 5 List of abbreviations............................................................................................................... 6 English Summary ................................................................................................................................. 7 Dansk resume ....................................................................................................................................... 9 Introduction ........................................................................................................................................ 11 Background ........................................................................................................................................ 12 Definitions and key concepts ......................................................................................................... 12 Consequences of Low back pain on daily activities ...................................................................... 16 Sick leave during pregnancy .......................................................................................................... 17 Treatment and prevention of low back pain................................................................................... 19 Exercise as treatment for low back pain during pregnancy ........................................................... 20 Interventions to reduce low back pain in pregnant women ........................................................... 21 Pregnancy and water exercise ........................................................................................................ 24 Aim and Outline of the Thesis ....................................................................................................... 25 Ethical Considerations ................................................................................................................... 27 Materials and Methods ....................................................................................................................... 27 (Study I and II) ........................................................................................................................... 27 Intervention .................................................................................................................................... 31 Outcomes ....................................................................................................................................... 31 Statistical analysis and sample size calculation ............................................................................. 34 Results ................................................................................................................................................ 36 Discussion .......................................................................................................................................... 55 Methodological Considerations, Strengths and Limitations .......................................................... 61 Overall Conclusion ............................................................................................................................ 67 Future Perspectives and Clinical Implications ................................................................................... 67 Reference List .................................................................................................................................... 69 Appendix ...................................................................................................................................... 70
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List of publications Paper I Mette Grønbæk Backhausen, Jane Bendix, Peter Damm, Ann Tabor, Hanne Kristine Hegaard. Low back pain intensity during pregnancy and associated predictors. A cohort study. (Re-submitted after revision, May 11th 2017 to BMC Pregnancy & Childbirth) Paper II Mette Grønbæk Backhausen, Peter Damm, Jane Bendix, Ann Tabor, Hanne Kristine Hegaard. The prevalence of sick leave: reasons and associated risk factors – a survey among employed pregnant women. (Under revision, submitted, February 28th to Sexual & Reproductive Healthcare) Paper III Mette Grønbæk Backhausen, Ann Tabor, Hanne Albert, Susanne Rosthøj, Peter Damm, Hanne Kristine Hegaard. The Effects of an Unsupervised Water Exercise Programme on Low Back Pain and Sick leave among Healthy Pregnant Women – A Randomised Controlled Trial. (Re-submitted after 2. Revision, May 14th 2017 to PLOS ONE)
The studies were supported by grants from TrygFonden, Zealand University Hospital, Rigshospitalet The Danish Rheumatism Association, Lundbeck Foundation The Augustinus Foundation, The Danish Associations of Midwives
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Preface and acknowledgements This work is the result of a collaboration between Rigshospitalet and Zealand University Hospital and was carried out at The Research Unit for Womens’s and Children’s Health, The Juliane Marie Centre, Rigshospitalet and at the department of Obstetrics and Gynaecology, Zealand University Hospital, Roskilde. Data for the included studies has been collected at both hospitals during the period 2013 to 2016.
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List of abbreviations BMI
Body mass index
CG
Control Group
DRI
Disability Rating Index
GA
Gestational age
IG
Intervention group
LBP
Low back pain
NRS
Numeric rating scale
ODI
Oswestry Disability Index
PGP
Pelvic girdle pain
RCT
Randomised controlled trials
RF
Risk factors
RMDQ
Roland Morris Disability Questionnaire
VAS
Visual analogue scale
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English Summary Low back pain is with a prevalence of 50-80%, one of the most common pregnancyrelated discomforts. Low back pain may lead to physical, psychological and social challenges and sick leave is often a result. The Danish national guidelines provide limited information of the management of low back pain, but physical exercise is considered a cornerstone. However, pregnant women tend to decrease physical exercise in general, while exercise types such as swimming and water exercise tend to increase during pregnancy. High quality studies investigating the effect of physical exercise on low back pain are lacking. To evidence-base the management of low back pain among pregnant women; it is important to investigate the effect of an intervention used in clinical practice as well as to identify women at risk. The aim was threefold; first to assess the prevalence of low back pain, physical disability and sick leave due to low back pain and to identify predictors of moderate to severe low back pain. Second, to investigate the prevalence of the general sick leave, related reasons for sick leave and to identify predictors of long-term sick leave among pregnant women. Finally, to assess the effect of an unsupervised, water exercise programme on low back pain intensity and days on sick leave, among healthy pregnant women. A cohort study was therefore performed in which all Danish-speaking women were invited at the routine ultrasound visits at 20 weeks of gestation to participate from August 2015 until March 2016 at Zealand University Hospital, Roskilde. A total of 566 pregnant women were included and the overall response-rate was 87%. The participants answered a questionnaire at 20 and 32 weeks of gestation (Study I and II). In study I, three out of four women reported any low back pain at 20 weeks of gestation, and the proportion increased to nine out of ten at 32 weeks. Of these women, one in three reported moderate to severe pain at 20 weeks, increasing to half of the women at 32 weeks. Both sick leave due to low back pain and physical disability
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increased with increasing low back pain scores. Pre-pregnancy low back pain, young age, multiparity and lower level of education were all identified as predictors of moderate to severe low back pain during pregnancy. In study II, the overall prevalence of sick leave was 56% of employed pregnant women in the first 32 weeks of gestation; more than one in four women reported long-term sick leave. The majority of reasons for sick leave were pregnancy-related, and low back pain was the reason most frequently stated. Fewer than one in ten stated the reasons to be work-related conditions. Predictors of long-term sick leave were; multiparity and pre-pregnancy low back pain, while women with an advanced degree education had a lower risk. Long-term sick leave was reported more frequently by pre-pregnancy nonexercisers and by women who worked shifts. To assess the effect of an unsupervised, water exercise programme on low back pain intensity and days on sick leave, a randomised controlled trial (Study III) was conducted, including 516 healthy pregnant women at Copenhagen University Hospital, Rigshospitalet from October 2013 until May 2015. A statistically significant effect of the water exercise on low back pain was found after 12 weeks, but the result did not seem not clinically significant, with an increase of only 0.38 on a pain scale from 0-10 (95% CI 0.02-0.74 p=0.04). No differences on the secondary outcomes were found; days on sick leave, physical disability nor on general health between the groups. More women in the water exercise group tended to have no low back pain at follow-up (21% vs. 14% p=0.07). In conclusion, to improve the management of women with low back pain and subsequently women with long-term sick leave, special attention should be considered for women with pre-pregnancy low back pain, multiparous women and women with lower level of education. Pregnant women with low back pain may benefit from water exercise.
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Dansk resume Lændesmerter er med en forekomst på mellem 50-80% en af de hyppigste gener hos gravide. Lændesmerter kan medføre såvel fysiske, psykiske samt sociale udfordringer og resulterer ofte i sygefravær. De danske nationale anbefalinger for svangre omsorgen indeholder begrænset information om behandlingsmuligheder, men motion anses som en central del af behandlingen. Imidlertid nedsætter mange gravide kvinder deres fysiske aktivitetsniveau generelt, hvorimod aktiviteter som svømning og vandtræning øges under graviditeten. Der mangler veltilrettelagte kliniske forsøg om fysisk trænings effekt på intensiteten af lændesmerter. For at kunne målrette en evidensbaseret behandling af lændesmerter hos gravide, er det vigtigt at få viden om effekten af behandlingselementer som allerede anvendes i klinisk praksis, samt at identificere kvinder med en øget risiko for lændesmerter. Formålet med denne ph.d. var dels at estimere forekomsten af lændesmerter, fysisk funktionsnedsættelse og sygefravær på grund af lændesmerter og dels at identificere prædiktorer for moderate til svære lændesmerter. Endvidere at estimere forekomsten af sygefravær, årsagerne hertil, samt at identificere prædiktorer for langtidsfravær hos gravide. Endelig at undersøge effekten af et ikke-superviseret træningsprogram i vand på intensiteten af lændesmerter og antal dages sygefravær hos raske gravide. Et kohortestudie blev derfor gennemført hvor alle dansktalende kvinder der modtog et tilbud om en rutine ultralydsscanning, blev inviteret til at deltage i, fra august 2015 til marts 2016 på Sjællands Universitets Hospital, Roskilde. I alt blev 566 gravide kvinder inkluderet og svarprocenten var 87%. Deltagerne besvarede et spørgeskema i henholdsvis graviditetsuge 20 og 32 (Studie I og II). I studie I, rapporterede tre ud af fire lændesmerter i graviditetsuge 20, tallet steg til ni ud af ti i graviditetsuge 32. Af disse kvinder, rapporterede en ud af tre moderate til svære lændesmerter i graviditetsuge 20 stigende til halvdelen i graviditetsuge 32. Antallet af sygefraværsdage steg, og det fysiske funktionsniveau blev forringet ved en stigende score for lændesmerter. Lændesmerter forud for graviditeten, lavere alder, multiparitet, samt lavere uddannelsesniveau blev alle identificeret som prædiktorer 9
for moderate til svære lændesmerter under graviditeten. Studie II viste at 56% af gravide kvinder i beskæftigelse, havde sygefravær i de første 32 uger af graviditeten. Mere end en ud af fire rapporterede langtidsfravær. Den største andel af fravær var relateret til graviditeten og den hyppigst angivne årsag var lændesmerter. Færre end en ud af ti beskrev arbejdsmiljøet som årsagen til fravær. Prædiktorer for landtidsfravær var; multiparitet, lændesmerter inden graviditeten, mens kvinder med en højere uddannelse havde lavere risiko for langtidsfravær. Langtidsfravær blev hyppigere rapporteret af kvinder, der ikke dyrkede motion inden graviteten, og af kvinder der havde skifteholdsarbejde. For at undersøge effekten af et ikke-superviseret træningsprogram i vand på intensiteten af lændesmerter og fravær fra arbejde, gennemførte vi et randomiseret kontrolleret studie (studie III), hvori 516 raske kvinder med planlagt fødsel på Rigshospitalet blev inkluderet fra oktober 2013 til maj 2015. Der var en statistisk signifikant lavere smertescore i vandtræningsgruppen sammenlignet med kontrol gruppen efter 12 uger, forskellen var dog ikke klinisk signifikant med en ændring på kun 0.38 på en smerteskala fra 0-10 (95% CI 0.02-0.74 p=0.04). Der var ingen forskel på de sekundære effektmål; antallet af sygefraværsdage, fysisk funktionsniveau eller generelt selvvurderet helbred mellem grupperne. Flere kvinder i vandtræningsgruppen rapporterede ingen lændesmerter ved opfølgning efter 12 uger (21% mod 14% p=0.07). På baggrund af resultaterne i afhandlingen konkluderes det at for at forbedre behandlingen af gravide kvinder med lændesmerter og dermed også nedbringe sygefraværet, skal man have særligt fokus på kvinder med lændesmerter inden graviditeten, flergangsgravide samt kvinder med lavere uddannelse. Gravide kvinder med lændesmerter kan profitere af vandtræning.
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Introduction Pregnancy is a time of many changes, both physical and psychological, some of which can lead to discomfort. One of the most common pregnancy-related discomforts is low back pain 1. The prevalence of low back pain is substantial, as more than half of all pregnant women indicate having pain in the lower back at some point during their pregnancy. What causes low back pain is still largely unknown, although it is believed to be multifactorial 2,3. Pregnant women suffering from low back pain are often physically challenged. They tend to experience problems sleeping, and everyday activities, such as walking and sitting, are also affected. The physical challenges lead to difficulties with performing tasks at work, and sick leave is often a result 4,5. The social and psychological challenges are described as a lack of control of everyday life, being dependent on one’s partner and others 6,7, fear of the condition being permanent, feeling the need to reconsider having a larger family 7 and concern about the employer’s reaction to the diminished work capacity 6. Low back pain represents a major economic burden for society: in 2007 the cost for sick leave alone was estimated at DKK 1.4 billion 8. The treatment of low back pain is multifaceted, but often includes different kinds of physical exercise 1. However, the existing evidence of exercise as an effective treatment for low back pain is of poor quality 1. Considering the number of women affected of low back pain a continued professional and scientific awareness is important. On this basis a cohort study was performed to investigate the prevalence of low back pain, sick leave and associated risk factors. A randomised controlled was conducted trial to study the effect of a water exercise intervention on low back pain intensity and sick leave.
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Background Definitions and key concepts Low back pain during pregnancy Low back pain during pregnancy has been studied since around 400 BC, when Hippocrates described his theory of the ‘widening of the female pelvis during the first pregnancy’ 9. From the 17th to the 19th century, the research was primarily focused on the pelvic joints and the main theory was that swelling was the cause of the condition. In 1926 the hormone relaxin was identified and the hypothesis arose that this hormone led to changes in the pelvic ligaments. It was not until the 1970s that the focus of research shifted towards the pain symptoms, when questionnaires were developed as a tool for measuring pain 10. In 1977 Mantle and colleagues 11 asked 180 recent mothers about their experiences of low back pain during pregnancy and found a prevalence of 49%. The multiple definitions and ways of measuring low back pain have resulted in wide variations of its estimated prevalence and difficulties in comparison between countries. In 2008 an expert working group published the European Guidelines, which suggested the following definition;
Low back pain
Pain between the 12th rib and the gluteal fold and includes pelvic girdle pain, which is a specific form of low back pain.
Pelvic girdle pain
Pain experienced between the posterior iliac crest and the gluteal fold, particularly in the vicinity of the sacroiliac joints. The pain may radiate to the posterior thigh and can also occur in conjunction with/or separately in the symphysis
Pelvic girdle syndrome
Daily pain in all three pelvic joints confirmed by objective findings
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The Guidelines states that pelvic girdle pain is a specific form of low back pain and the two conditions can occur simultaneously or separately 12. It has been argued that low back pain and pelvic girdle pain are two different conditions and they should be treated differently 13. However, in clinical practice the management of pregnant women with musculoskeletal complaints both in regard to recommendations and treatment are very similar. Nor do the national recommendations for antenatal care distinguish between the two conditions 14. The focus of interest in this thesis will therefore, be on low back pain defined according to the European guidelines, as this broader definition includes all pregnant women suffering from pain in the lower back and pelvic area and therefore obtains a full picture of women with pain during pregnancy. Prevalence Descriptive studies on low back pain have been performed in Europe, the Middle East, Australia, and in the USA. The prevalence of low back pain has been estimated retrospectively in late pregnancy or among recent mothers shortly after delivery to be between 42 and 91% 15–23. The estimated prevalence in the prospective studies varied between 49 and 81% 13,24–32. For an overview of the studies please see Appendix A. Only few Danish studies have been performed. In 1999 Larsen and colleagues 33 investigated the incidence of pelvic pain among 1600 pregnant women and found that 14% suffered from pelvic pain. In 2001 Albert and colleagues 34 studied 1460 pregnant women and found an incidence rate of 20% suffering from pelvic joint pain. Common for the two studies was that they included women with pelvic pain and used a physical examination to determine whether the women had pelvic pain or not. No study estimating the prevalence of low back pain in a Danish context exists. The onset of low back pain occurs for the majority of pregnant women in the first or second trimester 13,24–26 and 65% of the affected women experience pain on a daily basis 15. Initiatives to treat or prevent low back pain should be initiated at this time at the latest. Approx. 20 to 37% experience low back pain prior to pregnancy
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13,24,25,29,31.
The duration of low back pain varies from a single event to three months in 75% of the pregnant women with low back pain and 25% experience a duration of four months or more 24,29. The intensity of low back pain among pregnant women obviously varies greatly. Berg and colleagues 26 found that 9% suffered from severe pain during pregnancy whereas Skaggs and colleagues 32 found it to be 21% defined as a pain score of 8 or more on a numeric rating scale (NRS). Other studies have shown that 30% suffer from severe low back pain during pregnancy 24–26. A recent study suggested that cut points on a NRS for low back pain should be; 1-3 (mild pain), 4-6 (moderate pain) and 7-10 (severe pain) 35.
Women suffering from low back pain during pregnancy often experience a spontaneous recovery after birth, however 14 months postpartum one in five still reports pain 34,36 and 10% were classified with long-term pelvic girdle pain up to 11 years after birth 37. An association was also demonstrated between the severity of low back pain during pregnancy and persistent symptoms after pregnancy 38,39. Etiology The underlying etiology is still not fully understood and current theories include hormonal, mechanical, and physiological changes 1,2. The level of serum relaxin was found to be higher in pregnant women with severe pelvic pain than in healthy controls 40,41.
The hormone affects the laxity of ligaments causing larger range of movement of
pelvic joints 12,42, however a systematic review concluded that the level of evidence for this association was low 43. An observational study demonstrated that joint laxity was increased during pregnancy, but was not correlated with an increased serum relaxin level 44. Another systematic review showed an association between low back pain among pregnant women and enlarged motion of the pelvic joints 45. Others argue that the growing pregnancy causes a shift in the women’s center of gravity which increases the load on the musculature in the lumbar spine causing pain 46.
The increase in weight within a short time frame during pregnancy may also play a
role 47. Dysfunction of the abdominal and back muscles has also been discussed as possible contributing factor for low back pain in pregnant women
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46,48.
A recent study
used quantitative sensory testing and demonstrated that pain sensitivity was increased in pregnant women with low back pain due to physical and emotional changes 49. Risk factors Several risk factors for low back pain during pregnancy have been identified. Low back pain before the pregnancy was demonstrated to be of significant importance for low back pain during pregnancy 20,25,26,28,29,31. (See overview Appendix A). Ostgaard and colleagues 25 sent questionnaires to 855 women nine times during pregnancy, and found that low back pain during pregnancy was significantly associated with low back pain in previous pregnancies 25. The same association was found in two other studies from Sweden and Iran, respectively 26,31, as well as in smaller studies and in studies who collected data retrospectively 20,23,30. Low back pain in previous pregnancies 23,50 as well as a family history increased the risk of low back pain during pregnancy 18. Young age was found to be a risk factor in some studies 16,25,29. A large survey included data from 5400 recent mothers and showed that younger women more often reported low back pain than older women 16. Two other prospective studies also found young age to be a risk factor 25,29. In addition a cohort study found that young women reported a higher pain intensity that older women 24. Multiparous women had a higher risk of low back pain. Mogren and colleagues 18 found that even after adjusting for confounding factors multiparous women had twice the risk of low back pain compared with nulliparous women. This risk factor was also identified in four other studies 24,25,30,50. One study showed that a higher body mass index (BMI) in nulliparous women increased the risk of low back pain 23. Another study showed that women reporting low back pain had a higher BMI than those without 24. In the study by Kovacs and colleagues 28 lower educational level was shown to be a risk factor for low back pain. In the same study women with a higher anxiety score had an increased risk of reporting low back pain 28.
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Physically demanding work conditions have been demonstrated as a risk factor for low back pain in three studies 16,25,26. In a prospective study lifting and turning at work was associated with a higher risk of reporting low back pain
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and another study
identified twisting and bending as risk factors 25. Endresen and colleagues 16 furthermore identified working with hands at shoulder level or above as a risk factor.
Consequences of Low back pain on daily activities Physical disability and impaired quality of life. Low back pain affects the ability to perform normal daily tasks and consequently impedes ordinary activities. Several studies have shown that increasing low back pain intensity is associated with an increased physical disability 17,24,30,31,51. Looking at the single elements in physical disability, standing has shown to aggravate pain in more than half of women with low back pain 29 and walking aggravated pain in 34-43% 20,24,29.
Other physical tasks such as climbing stairs and lifting objects were found
difficult to do 24,29, but also sitting was found to aggravate pain in 50% of the women 24,29.
A study by Robinson and colleagues 52 reported that sixteen percent of women
with pain used crutches. Women with low back pain report lower quality of life 13,53. A cross-sectional study among 324 pregnant women, showed that women with low back pain had a significantly lower overall health-related quality of live than healthy controls 53. They further demonstrated a moderate correlation between physical ability and healthrelated quality of live in early pregnancy 53. Women with low back pain reported ‘poor health’ three times more often than women without low back pain in a sample of 891 recent mothers 5. In a study by Stapleton and colleagues 21 women who had experienced low back pain during pregnancy considered their health and quality of live after pregnancy worse than women with no pain. Sleep problems were reported by 30-60% of women suffering from low back pain 15,29,52 and Skaggs and colleagues 32 found that 80% of women with low back pain experience sleep problems defined as less than 4 hours of sleep per night compared to pregnant women without pain of whom only 8% experience sleep problems.
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Psychological and social consequences of low back pain Low back pain does not only have physical but also psychological and social consequences for the affected women. The existing literature on the experience of low back pain relates to pelvic girdle pain, a specific form of low back pain but it must be assumed that there are many similarities between the two related conditions and the studies presented are therefore found suitable for covering experiences of low back pain as well. The everyday life with pelvic girdle pain was described as a daily struggle with pain that influenced almost all daily activities including the ability to work 6,7,54. The pain was described as exhausting, affecting mood, sexual life and the relations to the near family negatively. Being a burden and questioning the ability of being a mother, while dealing with other people’s reactions was also described 6,7. In the study by Fredriksen and colleagues 55 web-based discussions regarding pelvic girdle pain were analyzed and showed that women often sought information on symptoms, diagnosis and treatment in order to decrease fear and uncertainty. Questions on how much the women should push themselves at work and in general were often discussed. Some women lacked support from their doctor and felt stigmatized 55. Investigating the views on and attitudes toward pelvic girdle pain among midwives Mogren and colleagues 56 found that pelvic girdle pain was perceived as a common clinical problem, but sometimes questioned whether the diagnosis was falsely placed by the pregnant women themselves or by others. An early onset of pelvic girdle pain was both interpreted as false symptoms and an indication of a risk of developing severe pelvic girdle pain. Support was given when symptoms occurred and this consisted of information regarding the condition and advice on living with it 56. Women suffering from low back pain expressed dissatisfaction with routine treatment and advice in antenatal care 54.
Sick leave during pregnancy Another consequence of the decreased physical ability among pregnant women, with and without low back pain, is not being able to carry out work tasks.
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General sick leave According to a report from the Danish Ministry of Employment 8 two out of three pregnant women spend an average of 48 days on sick leave during pregnancy. This is in accordance with other recent Scandinavian studies who also showed a prevalence of approx. 70% and an average of 47-73 days was spent on sick leave during pregnancy 4,57,58.
This has major socioeconomic costs 8 and is of particular concern in countries
where women account for a large part of the workforce, which is the case in Denmark and in the other Scandinavian countries, where 80% of all women in the fertile age group work outside the home 59. A number of risk factors for sick leave among pregnant women has been identified as multiparity with an adjusted hazard radio (HR) of 1.26 (95% CI 1.10-1.45), obesity 1.23 (95% CI 1.15-1.31), assisted reproductive technology 1.10 (95% CI 1.01-1.20), 60 and young age 57. One study found exercise to decrease the risk of sick leave HR 0.84 (95% CI 0.75-0.95) 60 while another study found non-exercisers to have an increased odds ratio of sick leave 1.79 (95% CI 1.69-2.31) 4. Sick leave due to low back pain A Danish study showed that approx. 40% of the women with pelvic girdle pain had been sick-listed for an average of twelve weeks during pregnancy 33. In a crosssectional study from 1999 the most frequently used pregnancy-related justification for sick leave was low back pain (pelvic girdle pain 34%, pelvic girdle syndrome 20% and back pain 5%) 61. The background for taking sick leave is often pregnancy related discomforts 4 and low back pain is a discomfort that often leads to long periods of sick leave during pregnancy 4,5,33,61,62. Other pregnancy related discomforts reported as reasons for sick leave were; nausea, haemorrhage and fatigue 4,61. Work related conditions such as walking, standing, lifting, long working days and working shifts have also shown to be associated with sick leave during pregnancy 63,64. Job adjustment among pregnant women have shown to reduce sick leave by 10 %
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65.
Only few studies have previously investigated multiple reasons of sick leave during pregnancy. In the most recent study 4, reasons for sick leave were pre-defined in six categories and in a Danish study from 1999 reasons were chosen from a list and the participants were allowed to choose up till three reasons for sick leave 61. Delivery Little is known about birth outcomes in women with low back pain during pregnancy and whether they differ from women without low back pain. A retrospective survey among 580 recent mothers found a correlation between low back pain during pregnancy and longer duration of labour, assisted delivery and an increased incidence of caesarean section 66.
Treatment and prevention of low back pain Limited evidence exists about women´s need for treatment and how many actually receive treatment and guidance concerning low back pain during pregnancy. Wang and colleagues 29 found in a survey including 950 pregnant women that 32% consulted their care provider regarding low back pain and of these women, only 25% received treatment. Other studies found that treatment was received by 7-25% of women with low back pain 15,20,28,30,32,67, however only 10-50% of the women who received treatment found it to be effective 30,32,67. The treatment often consisted of advice and included; rest, exercise 20,29, physiotherapy 15,28, massage 15,29 and the use a supportive belt 15,29,67.
Acupuncture and cold/hot compress were also suggested 29.
The Danish national recommendations of antenatal care 14 provide limited information of the treatment in women with low back pain, but suggest the use of provocation tests to identify women with pelvic girdle pain and a referral to physiotherapist for advice 14.
Acupuncture, water exercise and strength training are also suggested as
treatments with possible effects 14. Systematic reviews 1,68–70 have assessed the available evidence for treatment of low back pain during pregnancy and concluded that there is low quality evidence that exercise (on land or in water) may reduce low back pain among pregnant women.
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There is moderate to low quality evidence that exercise improves physical disability and reduces the number of days on sick leave. There is moderate to high quality evidence that acupuncture and pelvic belts may reduce pain intensity and increase physical function 1,68, but high quality studies are still lacking 1,68–70.
Exercise as treatment for low back pain during pregnancy For some women low back pain has such intrusive consequences on physical abilities. Because the underlying causes of low back pain are presumed to be an instability of the pelvis and dysfunction of the abdominal and back muscles, physical exercise as a mean to strengthen the core muscles and thereby decrease the instability, is often the treatment recommended. Furthermore, observational studies have demonstrated that low back pain among pregnant women can be prevented or reduced. Two studies 27,71 found that women who exercised ≥ 3 hours a week before pregnancy were less likely to report pelvic girdle pain during pregnancy, while women exercising 1-2 times a week were less likely to report low back pain. A case-control study among 5304 pregnant women found an association between exercise during pregnancy and a decreased risk of pelvic girdle pain 72. Another study found a higher number of years of physical activity before pregnancy decreased the risk of low back pain during pregnancy 73. This indicates that physical activity before and during pregnancy may have some effect in reducing the risk of low back pain and thereby also the risk of sick leave. National and international guidelines recommend pregnant women to be physically active 30 minutes per day at a moderate level 14,74. However, recent studies suggest that only 15-38% engage in physical activities as recommended during pregnancy 27,75,76.
The growing body, fatigue, discomfort and insecurity during exercise, are some of the reasons for not engaging in physical exercise 77–79.
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Interventions to reduce low back pain in pregnant women A total of 13 randomised controlled trials investigating the effect of an exercise intervention on low back pain and/or pelvic girdle pain among pregnant women were identified in the period from 1999 to 2015 (Table 1). Only two studies investigated the effect of a water exercise intervention on low back pain 80,81. Prevalence Among the RCTs, three studies investigated pregnant women with low back pain at inclusion whereas ten studies included women both with and without low back pain (Table 1). Six studies investigated the effect of exercise on the prevalence of low back pain 81–86 but only two studies found an effect 81,83. Among nulliparous women, Mørkved and colleagues 83 found significantly less women reporting low back pain, 44% in the intervention group vs. 55% in the control group and in the study by Granath and colleagues 81 19 women in the intervention vs. 34 women in the control group reported low back pain at follow up. Pain intensity Seven studies investigated the effect of exercise on low back pain intensity 80,82,84,85,87– 89
and four found an effect. The study by Kluge and colleagues 87 included 50 pregnant
women with low back pain and found after 10 weeks of combined home and supervised exercises, women in the intervention group reported significantly lower pain intensity. The study by George and colleagues 88 also included pregnant women with pain and found after 4-6 weeks of home exercises and manual therapy, a significant reduction in pain intensity among women in the intervention group. Kihlstrand and colleagues 80
included 258 pregnant women who were randomised to either 12 weeks of
supervised water exercise or standard care and found women in the water exercise group reported significantly less pain at 33 weeks of gestation. Three of these studies had a modest sample size (n= 50-169) and only included women with low back pain 87– 89.
Three studies investigated the effect of exercise on the intensity of pelvic girdle pain 90–92
and included pregnant women with pain at baseline. Two found an effect. The 21
study by Elden and colleagues 90 showed that women performing stabilizing exercises in a period of 6 weeks reported less pain at follow up (p=0.03). Kordi and colleagues 91 showed that home exercise and brisk walking reduced low back pain intensity significantly. This was a small study with only 30 women in each group and a limited description of the statistical analysis. Physical disability Seven studies investigated the effect of exercise on physical disability
83–85,87,88,91,92
and
four found an effect 83,87,88,91. The study by Mørkved and colleagues 83, women in the intervention group reported a significantly higher functional status on the Disability Rating Index, than women in the control group. In the studies by Kluge and colleagues and George and colleagues 87,88 a significantly higher functional ability was found among women in the intervention group, both studies only included women with pain at baseline. One of the studies was small (n=50) and reported baseline imbalance concerning age and parity 87. Sick leave Three studies 80,83,84 investigated the effect of exercise on sick leave due to low back pain and two found an effect. In the study by Stafne and colleagues 84 the proportion of women reporting sick leave was significantly lower in the intervention group (22% vs. 31%). Kihlstrand and colleagues 80 showed that a water exercise intervention reduced the number of women on sick leave due to low back pain significantly (7 vs. 17). Two studies investigated the total number of days on sick leave 81,88 and the study by Granath and colleagues 81 found less women on sick leave in the water-exercise group at follow-up. The later study was of low methodological quality; randomisation was performed by date of birth, no intention-to-treat and no baseline pain score was reported.
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Table 1 Overview of randomised controlled trials including exercise as intervention to prevent or reduce low back pain intensity and sick leave Author Year Country
Population
Low back pain Eggen N=257 2012 IG:129 Norway CG:128
Granath 2006 Sweden
N=390 IG1: 132 IG2: 134
George 2013 USA
N=169 (with pain) IG: 87 CG: 82
Haakstad 2015 Norway
N=105 (nulliparous) IG: 52 CG: 53
Kihlstrand N=244 1999 IG:124 Sweden CG:120
Kluge 2011 South Africa
N=50 (with pain) IG:26 CG:24 .
Martins 2013 Brazil
N = 60 (with pain) IG: CG: Miquelutti N=197 2013 (nulliparous) Brazil IG:97 CG:100
Mørkved 2007 Norway
N=301 (nulliparous) IG:148 CG:153
Intervention
Duration Outcome
Findings
1 weekly supervised group exercise. Abdominal and pelvic floor exercises
16-20 weeks
No effect on LBP prevalence OR: 0.77 (95%,CI:0.50;1.19) No effect on LBP intensity nor on physical disability
1. One weekly supervised landbased physical exercise 2. Water aerobics in groups Home stabilization exercises and manual therapy
LBP prevalence LBP intensity (NRS) Physical disability (RMDQ) LBP prevalence Sick leave (LBP)
4-6 weeks PGP/LBP intensity (NRS) Physical disability Sick leave 12 weeks LBP/PGP prevalence
2 weekly supervised Endurance, strength training incl. stretching Weekly 14 weeks supervised water gymnastics once a week in groups
Effect on LBP prevalence 19 vs 34 women p=0.04 Effect on sick leave, median days 9.8 vs 6.1, p
