(1020) Lifestyle intervention for an adequate gestational weight gain and better perinatal outcomes in obese women

Objective: Controversy exists about the amount of weight, if any, that obese pregnant women should gain during pregnancy. The Institute of Medicine (IOM) guidelines on gestational weight gain (GWG) recommended 5–9 kg for all classes of obesity. This study evaluates if a lifestyle intervention (LI) can guarantee an adequate GWG affecting perinatal outcomes.

Study Design: Prospective cohort study including singleton obese women (BMI ≥ 30) delivered at a tertiary hospital between 2016 and 2020. A group was randomly referred to an ad-hoc clinic for LI from both family centers and private practitioners. The LI started at the 9-12th week implementing a low-glycemic index, low-saturated fat diet, and physical activity. Follow-up was granted until delivery. Pregnancy and perinatal outcomes were prospectively collected using electronic medical records. The total GWG was categorized as Insufficient, Adequate or Excessive according to the IOM range. Data of women included in the LI were compared with the remnants receiving standard care (SC group) in different public and private settings.

Results: A total of 1874 obese singleton women delivered in the study period. Among them, 565 (30.1%) were included in the LI while 1309 received SC. The main maternal and pregnancy characteristics are reported in table 1. A significantly higher rate of women with a GWG out of the IOM recommendations was found in the SC group, both excessive and insufficient, while women in the LI groups showed higher adequate GWG, even though more severely obese were in the LI group. Interestingly, the SGA rate was significantly higher in the SC group (table 2) and after adjusting for age, BMI classes, country of origin, care provider, and gestational hypertension, the risk for SGA was increased by insufficient GWG (OR=1.31; 95%CI: 1.02–1.68) while it was reduced by LI (OR=0.66, 95%CI: 0.43–0.98).

Conclusion: SGA risk is associated with an insufficient GWG and may be preventable by applying an early lifestyle intervention in pregnancies complicated by obesity.