Maternal plasma and amniotic fluid cortisol and progesterone concentrations between women with and without term labor. A comparison.

OBJECTIVE: The purpose of the present study was to determine the amniotic fluid and maternal plasma concentrations of cortisol and progesterone in nonlaboring women at term and to compare them to those in women with active labor at term. STUDY
DESIGN: A prospective, cross-sectional study. Soroka Medical Center of Kupat Holim, Faculty of Health Sciences, Ben-Gurion University of the Negro, Beer-Sheva, Israel. Thirty-five healthy women with normal term pregnancies were classified according to labor status into two groups: group A (16 women with spontaneous, active labor at term) and group B (19 women not in labor).
RESULTS: We found a significant increase in the median concentration of plasma cortisol in women at term in active labor in comparison to those not in labor. In addition, the median concentration of cortisol in amniotic fluid in women in labor was also significantly higher than that in women not in labor. In contrast, no significant changes in median maternal plasma or amniotic fluid progesterone concentrations were detected between the groups.
CONCLUSION: Human parturition is associated with a significant increase in the concentration of cortisol in both maternal plasma and amniotic fluid. These findings suggest that cortisol plays an important but still-undetermined role in human parturition.