MON-LB8 A Preconception Lifestyle Intervention Maintained Throughout Pregnancy Improves Some Gestational and Neonatal Outcomes in Women With Obesity and Infertility

Abstract Background : Obesity in women of childbearing age is associated with infertility and increases significantly the risks of many pregnancy and neonatal complications. Adopting a healthy lifestyle prior conception and maintaining it during pregnancy may reduce these complications. Our aim was therefore to determine whether a lifestyle program targeting women with obesity and infertility and maintained during pregnancy improves gestational and neonatal outcomes. Methods : We report on 46 women who became pregnant and had available outcome data during pregnancy and at birth, among 127 women with infertility and obesity (body mass index, BMI ≥30 kg/m²), or overweight with PCOS (BMI ≥27 kg/m²), who were enrolled in a lifestyle randomized-controlled trial. Participants were randomized to the control group (CG, n=20), who received standard of care, or the lifestyle group (LSG, n=26), who followed a lifestyle program alone for 6 months, and then in combination with usual fertility care for 18 months or until the end of pregnancy. Pregnancy and neonatal outcomes were retrospectively retrieved from mothers’ and newborns’ medical records. Results : At enrollment, both groups were similar for age (29.3 vs 31.0 years), BMI (38.7 vs 38.4 kg/m2) and waist circumference (113.7 vs 112.7 cm). Preconception weight loss was significantly higher in the LSG compared to the CG (4.86 kg vs 1.21 kg, p=0.013), but gestational weight gains were similar (+10.83 vs +10.52 kg, p=0.987). During pregnancy, groups did not differ for the rates of preeclampsia, gestational diabetes or other clinical outcomes, but significantly less women in the LSG required insulin for treatment of their gestational diabetes (12.5% vs 42.1%, p=0.027) as well as urgent cesarean section due to failure of vaginal delivery (0.0% vs 21.1%, p=0.021). Regarding neonatal outcomes, there was no significant difference between groups for gestational age, weight at birth and head circumference, as well as rates of prematurity, LGA, SGA, birth defects or other clinical outcomes, but babies from the LSG displayed significantly lower tricipital skinfolds (4.73 mm vs 5.72 mm, p=0.031) and trends for lower sum of four skinfolds (16.61 mm vs 19.06 mm, p=0.056) and increased length at birth (50.82 cm vs 49.63 cm, p=0,053). Conclusion : In women with obesity and infertility, our lifestyle program initiated prior to fertility treatments and maintained throughout pregnancy improved their preconception weight and lifestyle, but not their gestational weight gain. Such intervention was nonetheless effective to reduce significantly some clinically relevant pregnancy and neonatal complications. If these results are replicated in a larger sample, it would strongly suggest that women with obesity should be supported to adopt a healthy lifestyle prior conception in order to increase their likelihood of giving birth to a healthy baby.