Evidence for differential regulation of the adipokine visfatin in the maternal and fetal compartments in normal spontaneous labor at term

Abstract

Objective: Visfatin, a novel adipokine with metabolic and immunoregulatory properties, has been implicated in the regulation of fetal growth, as well as in preterm labor. A gap in knowledge is whether spontaneous labor at term is associated with changes in the maternal and fetal concentrations of visfatin. The aim of this study was to determine if the presence of labor at term is associated with alterations in maternal and neonatal plasma visfatin concentrations.

Study design: This cross-sectional study included 50 normal pregnant women at term and their appropriate-for-gestational age (AGA) neonates in the following groups: 1) 25 mother-neonate pairs delivered by elective cesarean section without spontaneous labor, and 2) 25 mother-neonate pairs who delivered vaginally following spontaneous labor. Maternal plasma and cord blood visfatin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

Results: 1) The median visfatin concentration was higher in umbilical cord plasma of neonates born following a spontaneous labor at term than that of those who were born by an elective cesarean section (P=0.02); 2) in contrast, the median maternal plasma visfatin concentration did not differ significantly between patients with and without labor (P=0.44); and 3) there was a significant correlation between umbilical cord plasma concentration of visfatin and both maternal visfatin concentration (r=0.54, P=0.005) and gestational age (GA) at delivery (r=0.58; P=0.002) only in the absence of labor.

Conclusion: Term labor is associated with increased fetal, but not maternal, circulating visfatin concentrations. Previous reports indicate that preterm labor leading to preterm delivery is characterized by an increase in maternal plasma concentrations of visfatin. The observations reported herein support the view that there are fundamental differences in the endocrine and metabolic adaptations in normal labor at term and preterm labor.

Figure 1. Comparison between visfatin circulating concentrations in the presence and absence of labor in cord blood (A) and maternal plasma (B)

The median visfatin concentration was higher in umbilical cord plasma of neonates born following spontaneous labor at term than in those who were born by an elective cesarean delivery (4.8 ng/ml, interquartile range [IQR] 4.2-5.3 vs. 3.8 ng/ml, IQR: 3.3-4.7; p=0.02). In contrast, the median visfatin concentration in maternal plasma was not significant different between patient with spontaneous labor at term and those who underwent an elective cesarean delivery (8.5 ng/ml, IQR: 6.4-10.3 vs. 9.1 ng/ml, IQR: 7.6-10.0; p=0.44, Figure 1B).

Figure 2. Comparison between umbilical cord blood and maternal plasma visfatin concentrations in the absence (A) and presence of labor (B)

The median maternal plasma visfatin concentration was higher than in the umbilical blood regardless of the presence or absence of spontaneous labor (p<0.001 for both comparisons).