Fetal and maternal plasma leptin levels during the second half of normal pregnancies and those with Down syndrome.

ABSTRACT

OBJECTIVE: To assess the correlation of fetal and maternal plasma leptin concentrations during the second half of uncomplicated, euploid pregnancies and to compare these values with those obtained from pregnancies with Down syndrome. METHODS: Paired maternal venous and fetal umbilical blood samples were obtained during cordocentesis in 36 uncomplicated, euploid pregnancies and nine pregnancies with Down syndrome fetuses. Concentrations of leptin were measured by sensitive radioimmunoassay. RESULTS: Among pregnancies with euploid fetuses, there was significant correlation between both fetal and maternal leptin levels and gestational age (r = 0.464, p = 0.005 and r = 0.629, p < 0.001, respectively). Fetal plasma leptin concentrations also correlated with maternal levels (r = 0.485, p = 0.003), but fetal levels were significantly lower than maternal values (mean 2.12 +/- 0.44 ng/ml vs. 17.79 +/- 5.48 ng/ml, respectively; p < 0.001). Down syndrome fetuses had significantly lower fetal plasma leptin levels than gestational age-matched control euploid fetuses (0.72 + 0.54 ng/ml vs. 2.12 + 0.44 ng/ml; p < 0.002). However, there was no difference in maternal leptin concentrations between euploid and Down syndrome pregnancies. CONCLUSION: In euploid pregnancies, fetal leptin levels were significantly lower than the corresponding maternal values but increased across gestation. Down syndrome was associated with significantly lower fetal leptin levels.