Leptin Levels in Cord Blood : Relations to Birth Weight , Preeclampsia , Fetal Sex , Maternal Obesity and Gestational Weeks on Delivery

Lim, Y G; Jeon, Y H; Song, E S; Koh, S K; Im, M H; Lee, B I

Abstract

OBJECTIVE
Leptin is a 16-kD protein encoded by the ob/ob gene and produced mainly by adipocytes. Leptin signals the amount of fat stored in the body to the brain and affects food intake, energy expenditure, and thermogenesis to maintain a constant amount of stored body fat. In pregnancy, it was demonstrated that leptin is produced by non-adipose cell line, i.e. by placental trophoblasts as well as fetal adipocytes. In this study, we investigated the effect of birth weight, fetal sex, preeclampsia, maternal body mass index[BMI] on cord blood leptin concentrations.
METHODS
We determined serum leptin levels using radioimmunoassay[RIA] in cord veins of 115 pregnant women that included 28 preeclampsia. Fetal sex were 63 male and 52 female.
RESULTS
Cord leptin levels were significantly correlated with birth weight in multivariate analysis controlling potential confounders[gamma= 0.6125, P< 0.001 ]. Leptin levels in female fetus[ 7.35+/-5.03 ng/mL ] were significantly elevated than male fetus[ 5.37+/-4.64 ng/mL ][ gamma= 0.3849, P< 0.001 ], independent of obesity. But preeclampsia, maternal BMI, and gestational weeks on delivery had no significant effect on cord blood leptin levels[ preeclampsia: gamma= -0.006, P = 0.950, maternal BMI: gamma= 0.1732, P = 0.069, gestational weeks on delivery: gamma= -0.1132, P = 0.105, respectively ].
CONCLUSION
These data suggest that the effect of fetal birth weight and sex on cord leptin level was more pronounced than utero-placental and maternal effect.