Correlations between umbilical and maternal serum adiponectin levels and neonatal birthweights

Objective. To measure adiponectin levels in maternal serum and umbilical cord serum at delivery, and examine whether or not there are correlations between adiponectin levels and neonatal birthweights, maternal body weights and body mass indexes. Study design. The study included 84 healthy mothers who had given birth to healthy neonates. Adiponectin levels in maternal serum and umbilical cord serum were determined by radioimmunoassay and compared. Results. The ranges of adiponectin levels for umbilical cord serum and maternal serum were 22.7-78.4 mug/ml and 4.0-43.3 mug/ml, respectively. Umbilical serum adiponectin levels (46.9 +/- 1.2 mug/ml) were significantly higher than maternal serum adiponectin levels (16.1 +/- 0.8 mug/ml) (p < 0.001). No correlation was found between the adiponectin levels in maternal serum and those in umbilical cord serum (r = 0.158, p = 0.151). Umbilical serum adiponectin levels were significantly correlated with both neonatal birthweights (r = 0.454, p < 0.001) and gestational ages at birth (r = 0.295, p = 0.006), but not with maternal serum adiponectin levels. Maternal serum adiponectin levels were only negatively correlated to maternal weights and body mass index at delivery (r = 0.288, p = 0.008; r = 0.372, p < 0.001). Conclusion. The levels of adiponectin were higher in umbilical cord serum than in maternal serum. Moreover, the adiponectin levels in umbilical cord serum were found to correlate positively with neonatal birthweights. Therefore, fetal adiponectin, not maternal serum adiponectin, may be involved in fetal development during late pregnancy.