Leptin and gestational weight gain: Relation of maternal and cord blood leptin to birth weight

OBJECTIVES: To determine maternal serum leptin concentrations throughout normal pregnancy, as well as cord blood leptin concentration, and to correlate serum and cord blood leptin levels with gestational weight gain and birth weight, respectively. METHODS: This study comprised 52 normal pregnant women, including 11 in the first, 19 in the second, and 22 in the third trimester, in addition to 30 healthy, fertile nonpregnant women of comparable age and with normal body mass index (BMI). Maternal blood and fetal cord blood samples were withdrawn from the normal, healthy pregnant women and the nonpregnant controls for the determination of serum leptin by a specific radioimmunoassay. RESULTS: Maternal serum leptin concentrations in the first trimester did not differ significantly from those of healthy nonpregnant control subjects, whereas leptin concentrations in the second and third trimesters were elevated significantly. There were significant positive correlations between maternal serum leptin concentration and gestational age, gestational weight, and BMI. Cord blood leptin concentration correlated positively with birth weight and third trimester maternal serum leptin. CONCLUSION: Elevated serum leptin is associated with maternal adiposity and risk of developing large for gestational age infants. Copyright (C) 1999 by the Society for Gynecologic Investigation.