interest included: risks of stillbirth, neonatal death, 5-minute. Apgar score ... S306 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2017 ...
ajog.org
Poster Session III
518 The utility of a customized small for gestational age standard for pregnancies complicated by obesity
Ruofan Yao1, Sarah Foster2, Aaron Caughey3
1 University of Maryland Medical Center, Baltimore, MD, 2Drexel University School of Medicine, Philadelphia, PA, 3Oregon Health & Science University, Portland, OR
OBJECTIVE: Maternal obesity has been associated with higher birth
weight. A customized standard to redefine thresholds for small for gestational age (SGA) in pregnancies complicated by obesity may help to better identify at-risk fetuses. STUDY DESIGN: This was a retrospective cohort study of all nonanomalous singleton neonates born in Texas from 2006-2011. Analysis was limited to births between 34 and 42 weeks gestation. Two SGA birth weight standards (birth weight 10th centile) were generated, one using the entire population (SGApop) and another only with obese pregnancies (SGAcust). The outcomes of interest included: risks of stillbirth, neonatal death, 5-minute Apgar score below 7 and NICU admission. Multivariable logistic regression analysis was performed to estimate the risks associated with each SGA standard compared to pregnancies that were appropriate for gestational age (AGA, 10th and 90th centile) among the obese cohort. The regression models were adjusted for potential confounders. RESULTS: After exclusion, 2,332,824 births were analyzed. Using the population-based standard, the prevalence of SGA complicated by obesity was 8.3%, compared with 10.4% using the customized standard. An additional 10,776 pregnancies were identified as SGA (SGAcust-pop). The risk of stillbirth for SGApop was 5.6/1,000 births compared with 1.0/1,000 births among SGAcust-pop. Compared to obese AGA pregnancies, the aOR for stillbirth was 6.49 [5.47, 7.71] for SGApop, and 1.51 [0.82, 2.75] for SGAcust-pop. The risks for the remaining neonatal complications were slightly higher for SGAcust-pop group compared to AGA group: neonatal death OR 1.39 [1.04, 1.85], low 5-minute Apgar 1.28 [1.07, 1.53] and NICU admission 1.13 [1.03, 1.25]. These risks were lower than SGApop (Table). CONCLUSION: Using a customized SGA standard for pregnancies complicated by obesity identifies a subgroup of pregnancies with an increased risk for neonatal complications, though not at increased risk of stillbirth.
519 Racial/ethnic differences in the association between obesity and gestational diabetes
Ruofan Yao1, Bo Park2, Kathleen Browne1, Aaron Caughey3 1 University of Maryland Medical Center, Baltimore, MD, 2Johns Hopkins University, Baltimore, MD, 3Oregon Health & Science University, Portland, OR
OBJECTIVE: There are known racial/ethnic differences in the development of obesity associated type 2 diabetes and cardiovascular diseases. Therefore, we set out to determine the racial/ethnic differences in the development of obesity associated gestational diabetes (GDM), as well as the common neonatal complications associated with GDM. STUDY DESIGN: This was a retrospective cohort analysis of singleton non-anomalous births in Texas between 2006 and 2011. Analysis were stratified based on maternal pre-pregnancy BMI class and racial/ethnic category (4 BMI and 4 racial/ethnic categories). Underweight and pregestational diabetic women were excluded. The rates of GDM and complications such as large for gestational age (LGA), and neonatal deaths were calculated for each stratum.
S306 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2017
ajog.org
Poster Session III
Multivariable logistic regression analysis was performed to estimate the odds ratio (OR) for the outcomes of interest. RESULTS: After all exclusions there were more than 2.3 million births for analysis and over 88 thousand complicated by GDM. The risk of GDM increased as BMI increased for all racial/ethnic groups. However, between each BMI class, Non-Black and NonWhite Hispanics and Asian were at higher risk than Non-Hispanic Blacks and Whites. Using Non-Hispanic White normal weight women as the reference group (1.9%), the rate of GDM among Hispanic obese group (7.5%, p
