Chemerin concentrations in maternal and fetal compartments: Implications for metabolic adaptations to normal human pregnancy

Objectives: Chemerin, a novel adipocytokine, has been implicated in major metabolic and inflammatory processes. Study aims were to determine whether circulating maternal chemerin concentration (1) differs between pregnant and non-pregnant women, (2) changes as a function of gestational age, and (3) correlates with maternal insulin resistance. In addition, we investigated which compartment, maternal, fetal or placental, is the source of chemerin in maternal circulation. Methods: The study included three groups: Non-pregnant (n=18), pregnant women in the first trimester (n=19) and pregnant women in the third trimester (n = 33). Chemerin was measured in cord blood and in maternal serum samples taken before and after delivery. Chemerin mRNA expression was evaluated in fetal and human adult tissues. Results: Chemerin serum concentration was significantly higher in pregnant women in the third trimester than in non-pregnant and pregnant women in the first trimester. Chemerin concentration positively correlated with body mass index (BMI) and insulin resistance. Antenatal chemerin concentration was significantly lower than that during the postpartum period. Neonatal chemerin did not correlate with maternal one. Chemerin mRNA expression was abundant in fetal and adult liver and omental fat, but relatively low in placenta. Conclusions: Chemerin is increased during normal gestation and is associated with maternal BMI and insulin resistance. Maternal tissues, possibly liver and adipose tissue, contribute to the increased maternal chemerin concentration.