Maternal serum, amniotic fluid and cord leptin levels at term: their correlations with fetal weight.

AIMS: To investigate the relationship between fetal weight and leptin levels in maternal serum, amniotic fluid and umbilical cord.

METHODS: Forty pregnant women presenting for antenatal care at early weeks of gestation were enrolled for the study. Maternal and cord blood samples for leptin measurement were obtained at birth. Amniotic fluid samples were recovered by amniotomy performed during labor. Maternal body mass index and placental weight were also recorded. Leptin measurement was carried out using the ELISA method. Spearman's correlation test was used for comparison of non-parametric data.

RESULTS: Leptin concentration in venous cord blood correlated significantly with birth weight and placental weight whereas maternal serum and amniotic fluid leptin levels did not show correlation with birth weight. There were no significant correlations between leptin levels in maternal serum, cord blood and amniotic fluid.

CONCLUSION: We conclude that lack of correlation between leptin levels in mother, cord and amniotic fluid suggest that these compartments may be non-communicating separate units or have different mechanisms regulating leptin synthesis or degradation, and that leptin in maternal blood and amniotic fluid may not have a direct effect on fetal growth but rather a different role in pregnancy.