Maternal weight gain regulates omega-3 fatty acids in male, not female, neonates: A cross-sectional study

The fetus largely depends on maternal supply and placental transport for its source of long-chain polyunsaturated fatty acids (LCPUFAs), which are essential for proper neurological and cardiovascular development. Pregnancy complications such as diabetes reduces neonatal LCPUFA supply, but little is known of how fatty acid delivery is affected by maternal body type or weight gain in uncomplicated pregnancies. In a cross-sectional study of maternal-neonatal pairs at term, we sought to determine the effect of gestational weight gain on neonatal LCPUFA supply. Forty maternal-neonatal pairs of uncomplicated (no gestational hypertension or diabetes) term pregnancies were recruited upon admission to Oregon Health & Science University Labor & Delivery for scheduled cesarean section. Maternal and umbilical cord plasma fatty acid profiles were measured using gas chromatography- mass spectrophotometry. First trimester weight gain was negatively correlated with maternal n-3 LCPUFA (r = -0.80, P = .0002), and this was not affected by fetal sex. High maternal weight gain in the first trimester was negatively associated with cord n-3 polyunsaturated fatty acid levels (r=-0.70, P = .03) and placental thickness (r=-0.69, P = .03) in male, but not female, offspring. High maternal weight gain in the first trimester is associated with a thinner placenta and low levels of n-3 LCPUFA in male offspring. Further study is required to confirm that male offspring are at a higher risk of poor outcomes associated with high maternal weight gain early in pregnancy.