Decreased maternal serum leptin in pregnancies complicated by preeclampsia

To determine whether circulating levels of leptin differed between women with preeclampsia and women who had an uncomplicated pregnancy.

Maternal and umbilical venous plasma leptin concentrations obtained at delivery were compared in 36 pairs of women with either preeclampsia or normal pregnancy, matched 1:1 for prepregnancy body mass index and fetal gestational age at delivery.

Prepregnancy body mass index was 21.1 +/- 2.1 kg/m2 in either study group (range 17.6-25.3 kg/m2 and 17.7-25.3 kg/m2 in the normal and preeclamptic group, respectively). Mean fetal gestational age at delivery was 40.1 +/- 1.3 weeks and 40.1 +/- 1.2 weeks in the normal and preeclamptic group, respectively. Median leptin concentrations were significantly lower (P <.0001) in women with preeclampsia (8.3 ng/mL, range 3.5-20.0 ng/mL) than in normal pregnant women (20.2 ng/mL, range 6.0-63.7 ng/mL). Median umbilical venous leptin was not significantly different between groups (preeclampsia 11.8 ng/mL, range 2.0-37.2 ng/mL; normal 7.6 ng/mL, range 1.6-24.3 ng/mL; P = .377). Umbilical venous leptin levels correlated positively with birth weight in both groups (preeclampsia rho = 0.501, P = .002; normal rho = 0.517, P = .001), whereas no correlations were found between maternal and fetal hormone concentrations. Maternal leptin concentrations did not correlate with birth weight.

Our data suggest that the correlation between umbilical venous leptin concentration and birth weight is independent of the presence of preeclampsia. Given the inconsistency in literature concerning circulating leptin levels in preeclampsia, further studies should investigate the regulatory systems of leptin in preeclampsia.