Effect of omega-3 supplementation in pregnant women with obesity on newborn body composition, growth and length of gestation: A randomized controlled pilot study

Abstract

Maternal obesity, a state of chronic low-grade metabolic inflammation, is a growing health burden associated with offspring adiposity, abnormal fetal growth and prematurity, which are all linked to adverse offspring cardiometabolic health. Higher intake of anti-inflammatory omega-3 (n-3) polyunsaturated fatty acids (PUFA) in pregnancy has been associated with lower adiposity, higher birthweight and longer gestation. However, the effects of n-3 supplementation specifically in pregnant women with overweight and obesity (OWOB) have not been explored. We conducted a pilot double-blind randomized controlled trial of 72 pregnant women with first trimester body mass index (BMI) ≥ 25 kg/m2 to explore preliminary efficacy of n-3 supplementation. Participants were randomized to daily DHA plus EPA (2 g/d) or placebo (wheat germ oil) from 10–16 weeks gestation to delivery. Neonatal body composition, fetal growth and length of gestation were as-sessed. For the 48 dyads with outcome data, median (IQR) maternal BMI was 30.2 (28.2, 35.4) kg/m2. In sex-adjusted analyses, n-3 supplementation was associated with higher neonatal fat-free mass (β: 218 g; 95% CI 49, 387) but not with % body fat or fat mass. Birthweight for gestational age z-score (−0.17 ± 0.67 vs. −0.61 ± 0.61 SD unit, p = 0.02) was higher, and gestation longer (40 (38.5, 40.1) vs. 39 (38, 39.4) weeks, p = 0.02), in the treatment vs. placebo group. Supplementation with n-3 PUFA in women with OWOB led to higher lean mass accrual at birth as well as improved fetal growth and longer gestation. Larger well-powered trials of n-3 PUFA supplementation specifically in pregnant women with OWOB should be conducted to confirm these findings and explore the long-term impact on offspring obesity and cardiometabolic health.