Physical Activity for the Prevention of Gestational Diabetes: A Meta-Analysis of Randomized Controlled Trials

s / Annals of Epidemiology 24 (2014) 682e702 701 Conclusions: The differences in SGA prevalence bymining activity were fully explained by the differences in prevalence of maternal tobacco use. Maternal tobacco use continues to be a major determinant of SGA. P80. Physical Activity for the Prevention of Gestational Diabetes: A Meta-Analysis of Randomized Controlled Trials Lindsey M. Russo BS, Karen A. Ertel PhD, Brian W. Whitcomb PhD. University of Massachusetts Amherst Purpose: Gestational diabetes (GDM) affects up to 10% of pregnancies and is associated with increased incidence of pregnancy complications, adverse pregnancy outcomes, and maternal and fetal risks of chronic health conditions later in life. Physical activity (PA) has been proposed as a low-cost prevention for GDM, and is supported by observational studies, but experimental research assessing its effectiveness is limited and conflicting. The goal of this project is to perform a meta-analysis of published randomized controlled studies of PA and GDM. Methods: We searched MEDLINE and Cochrane library for all randomized controlled studies that met our search criteria. Tomeet eligibility, studies had to randomize participants to an exercise-only based intervention (i.e., separate from dietary interventions) and present data regarding GDM risk. Two authors were involved in the database search, assessment of eligibility for inclusion, and abstraction of data from included studies. Cochrane Review Manager Software was used to derive a summary relative risk (RR) and 95% confidence interval (CI) utilizing a fixed-effects model with the MantelHaenszel method and IÂ as a test of heterogeneity. Results: Six studies were identified. Meta-analysis yielded a relative risk of GDM of 0.78 (95% CI 0.59-1.02, p1⁄4.07) comparing the exercise intervention group to the control group. IÂ was equal to 25%. 4. Conclusions: The results from our meta-analysis, though not statistically significant, are consistent with the possibility that PA may provide a slight protective effect against the development of GDM. Additional studies are warranted to help inform evidence-based obstetrical guidelines. P81. Clustering of Retrospectively Reported and Prospectively Observed Time-To-Pregnancy Among Women in a Preconception Cohort Katherine J. Sapra MPH, Alexander C. McLain PhD, Jose M. Maisog MD, MS, Rajeshwari Sundaram PhD, Germaine M. Buck Louis PhD, MS. Eunice Kennedy Shriver National Institute of Child Health and Human Development Purpose: Two previous studies reported high clustering of retrospectively reported time-to-pregnancy (TTP). Given the limited validity of retrospectively reported TTP despite its frequent use in epidemiologic research, we assessed TTP clustering in a unique cohort of women with both retrospectively reported TTPs and 1 prospectively observed TTP. Methods: 501 couples discontinuing contraception for purposes of becoming pregnant were followed until hCG pregnancy or 12 months of unsuccessful trying; women experiencing losses could re-enroll. At enrollment, women retrospectively reported TTP for all prior planned pregnancies. Prospectively observedmenstrual cycles defined prospective TTP. Frailty models with lognormal distributionwere used to estimate clustering as measured by frailty variance, with separate models comparing 1) all retrospective TTPs and 2) all retrospective and prospective TTPs. Logistic regression models were used to assess clustering of conception delay (TTP >6) in retrospective and prospective pregnancies. Models were adjusted for maternal age, BMI, and smoking for each pregnancy attempt. Results: 75 women contributed 180 retrospective and 91 prospective TTPs. Median age at enrollment was 33 (IQR: 29, 36); median BMI was 27 (IQR: 23, 32); 11% of women smoked. Overall, TTP clustering was high (frailty variance1⁄40.89) among retrospectively reported pregnancies, but significantly lower when modeling retrospective and prospective TTP (frailty variance1⁄40.32; p-value for difference1⁄40.05). Prospectively observed conception delay was significantly more common in women reporting past conception delay (OR1⁄42.87, 95% CI1⁄41.05-7.91). Conclusions: TTP clustering is high for retrospectively reported TTP but low when including prospectively observed TTP. Conception delay may be a better assessment of prior fecundity. P82. The Association Between Maternal Depression During Pregnancy and Adverse Birth Outcomes: A Retrospective Cohort Study of Prams Participants Kenesha Smith MSPH, Larissa R. Brunner Huber PhD, Jan Warren-Findlow PhD, L. Michele Issel PhD. University of North Carolina at Charlotte Purpose: Women of reproductive age are at higher risk for depression; thus it is vital to examine the relationship between depression and negative birth outcomes. The purpose of this study was to investigate whether maternal depression during pregnancy affected adverse pregnancy outcomes, specifically preterm birth and small for gestational age (SGA). Methods: This study included 4,123 women who participated in the 20092011 Utah Pregnancy Risk Assessment Monitoring System, an ongoing surveillance project that investigates maternal behaviors in women who have recently had a live birth. Women self-reported information on depression and outcome data were obtained from birth certificates. Logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Results: Women who self-reported a diagnosis of depression during pregnancy had statistically significant increased odds of preterm birth as compared to women who had not been diagnosed with depression (OR1⁄41.51; 95% CI: 1.07, 2.12); there was no association between depression and SGA (OR1⁄40.92; 95% CI: 0.63, 1.34). After adjustment for prenatal care visits, the depression-preterm birth association was attenuated and no longer significant (OR1⁄41.29; 95% CI: 0.90, 1.85). After adjustment for smoking, there continued to be no association between depression and SGA (OR1⁄40.80; 95% CI: 0.54, 1.20). Conclusion: The findings of this study do not support amaternal depressionadverse birth outcomes relationship among a predominantly healthy population of non-Hispanic White, well educated women. Future studies should focus on other populations of women (i.e. minorities) to determine if there is an association for these subgroups.