ABSTRACT
PURPOSE: Leptin, a product of the ob gene, is a 16-KDa protein that is mainly expressed in the adipose tissue and involved in the regulation of body weight. Elevated levels of serum leptin is noted in pregnant woman and the placenta is the site of nonadipose tissue production of leptin. In this study, we investigated the effect of serum leptin concentrations on fetal growth to estimate the effect of leptin on fetal growth. METHOD: Leptin concentrations were measured in venous and arterial cord blood and maternal serum at birth using a specific radioimmunoassay employing human recombinant leptin(Human Leptin RIA kit; Linco research, St. Louis, Mo). Thirty two full term pregnant women(n=32) had no medical complications and delivered the healthy babies(male=14, female=18). RESULTS: Serum leptin levels were 1.51 - 19,36 ng/ml(mean 7.16, SD 3.76) in arterial cord blood and 1.59 - 16.18(mean 7.47, SD 4.08) in venous cord blood and there was no difference between arterial and venous cord blood. Serum concentrations in arterial and venous cord blood were positively correlated with birth weight(r=0.7181, 0.6970; p<0.0001). There was no correlation in maternal BMI, maternal serum leptin and cord blood leptin concentrations. CONCLUSION: These findings suggest that cord blood leptin independently contributes to fetal body weight regardless of maternal serum leptin and body weight.