Correlation of maternal serum and amniotic fluid leptin and insulin levels with neonatal birth weight

Background: Numerous studies correlated maternal serum and fetal cord leptin levels in pregnancy with new born weight (NBW) and maternal body mass index (BMI). However, there are only a few published studies concerning amniotic fluid leptin and its possible relationship to fetal growth and NBW. Objective: To correlate leptin and insulin in amniotic fluid and maternal serum collected at 16-20 gestational weeks to NBW. Methods: This was an observational study in which maternal serum leptin, insulin, and amniotic fluid leptin and insulin, studied from 70 healthy pregnant women undergoing amniocentesis for karyotyping, at 16-20 weeks' gestation. NBW was correlated with maternal BMI and leptin and insulin levels in maternal serum and amniotic fluid. Results: Maternal serum leptin was detected as the best predictor of NBW. Squared correlation coefficient, r² = 0.09, was statistically significant (P < .01). Maternal BMI correlated significantly with serum levels of insulin and leptin r²= 0.16 and 0.27 respectively, P < .01. Conclusions: In normal pregnancies, amniotic fluid leptin correlates partially with NBW. Maternal serum leptin correlates significantly with NBW.