Lifestyle Intervention to Promote an Adequate Gestational Weight Gain and Improve Perinatal Outcomes in a Cohort of Obese Women

Objective: This study aims to evaluate the correlation of gestational weight gain (GWG) with pregnancy and perinatal outcomes in a cohort of obese women class I-III receiving standard care (SC) or lifestyle intervention (LI). Methods: This is a prospective cohort study including singleton obese women (body mass index, BMI ≥ 30) who delivered between 2016 and 2020. Women exposed to a LI were referred to an obesity weight management ad hoc clinic. Women followed by family centers or private settings represented the SC group. The LI started between the 9 and 12th week, consisting of a low-calorie diet and physical activity program. Pregnancy and perinatal outcomes were prospectively collected. Women included in the SC group were followed, simply checking their pregnancy and health status, providing general recommendations on a healthy lifestyle in pregnancy. GWG was categorized as insufficient, adequate, or excessive according to the Institute of Medicine (IOM). 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. Women in SC showed a higher rate of GWG out of the IOM recommendations (excessive/insufficient), while women in the LI group showed higher adequate GWG. The small-for-gestational-age (SGA) rate resulted to be higher in the SC group. Once adjusting for age, BMI, country of origin, provider, and gestational hypertension, the risk for SGA was increased by insufficient GWG (OR = 1.25; 95%CI: 1.03–1.59), while it was reduced by LI (OR = 0.67, 95%CI: 0.42–0.98). Conclusions: In a cohort of obese women, the exposure to an LI was associated with more adequate GWG, reduced insufficient weight gain, and a decreased risk of SGA infants.