(629) Evaluation of Short-term Perinatal Outcomes with Expanded Gestational Weight Gain Parameters

Secondary analysis of a prospective multicenter cohort study of nulliparous, singleton pregnancies (2010-2013). Patients with a pre-pregnancy body mass index (BMI) of 18.5 kg/m² or greater, with pregnancy GWG within IOM guidelines or up to 10 lbs above were included. Pregnancies affected by genetic or structural anomalies, pregnancy loss < 20 weeks’, or missing key outcome data were excluded. The primary outcomes were a composite maternal morbidity and neonatal morbidity and mortality. We estimated the incidence of maternal and neonatal composites by GWG. Logistic regression modeling compared morbidity composites between individuals within IOM GWG guidelines compared with up to an additional 10 lbs, stratified by BMI category.

Results: Of 4487 pregnancies, 2137 (48%) had GWG within IOM guidelines and 2350 (52%) had up to an additional 10 lbs gained. Additional weight gain was associated with higher pre-pregnancy BMI and age < 35 years. There was a higher odds of composite maternal morbidity (aOR 1.29, 95% CI 1.14-1.47) but not neonatal morbidity (aOR 0.94, 95% CI 0.83-1.08) in those with additional weight gain (Table). Findings were the same when stratified by BMI category among people with normal and overweight BMI but inference was limited among the obesity subgroups with statistical insignificance and wide confidence intervals (Figure).

Conclusion: Expanded GWG (10 lbs above IOM guidelines) was associated with higher odds of short-term adverse maternal outcomes but not neonatal outcomes when compared with GWG within IOM guidelines. Further research is needed to identify GWG targets which optimize both maternal and neonatal health.