Changes in plasma endothelin-1 after elective cesarean section in women with preeclampsia and the relationship to thrombocytopenia

Maternal and fetal circulating sKL and ET-1 levels as function of normal labor at term

OBJECTIVES

To determine whether labor is associated with alterations of the levels of soluble c-kit ligand (sKL) and endothelin-1 (ET-1) in maternal plasma and umbilical cord blood.

METHODS

The sKL and ET-1 levels were investigated in umbilical cord and maternal plasma on the day of delivery in 18 pregnant women with vaginal delivery during labor, 18 non-pregnant women and 9 pregnant women before cesarean delivery, using an ELISA assay.

RESULTS

Umbilical cord plasma sKL levels were significantly higher than the maternal plasma in both types of delivery (p = 0.0001, p < 0.0001, respectively). However, maternal plasma ET-1 levels in the presence of labor were significantly higher than the cesarean delivery group (p < 0.0001). No difference was noted for sKL and ET-1 in umbilical cord vessels of both groups. Furthermore, a highly significant inverse correlation was documented between the individual levels of cord plasma ET-1 and the levels of cord plasma sKL (r = -0.6269, p = 0.0054).

CONCLUSIONS

The sKL levels found in umbilical cord plasma are consistent with the pleiotropic effects of sKL in facilitating the transition of the fetus to the neonatal stage. The reduced ET-1 maternal plasma levels, compared to non-pregnant women, probably are indicative of a putative mechanism for embryo protection from vasoconstriction sequelae. This assumption is strengthened by the corresponding ET-1 levels in umbilical cord plasma.