Different modes of delivery and hormonal stress response

The aim of the study was to determine how the type of delivery affects the stress response cycle and the level of cortisol, progesterone and corticoliberin.

The study was conducted among 26 pregnant women admitted to the Gynecology and Obstetrics Ward due to an approaching delivery date or the onset of labor. The participants were aged between 20 and 41 years, with a mean age of approximately 30 years. After delivery, blood was drawn in parallel from the maternal antecubital vein, the umbilical cord vein and the umbilical cord artery. The levels of stress hormones were assessed by ELISA. The results were subjected to statistical analyses, and correlation coefficients were calculated for individual variable pairs. The analysis also examined the participation of pregnant woman in antenatal education.

A high correlation was observed between cortisol and progesterone levels in venous and arterial cord blood and physiological delivery. The mean cortisol level was 247.37 ng/mL in venous cord blood and 233.59 ng/mL in arterial blood and the respective mean progesterone levels were 331.81 ng/mL and 342.36 ng/mL. The highest cortisol concentration was determined in the primiparas umbilical cord blood (236.182 ng/mL in the vein, 230.541 ng/mL in the artery). Correlation between cortisol level in venous and arterial cord blood and prenatal education was also noted (venous cord blood: r = -0.5477; F = 10.2833; p = 0.0038; cord arterial blood: r = -0, 4436; F = 5.8789; p = 0.0232).

The results obtained emphasize the importance of the hypothalamic-pituitary-adrenal (HPA) axis as one of the potential mechanisms actively involved in childbirth. The determined levels of cortisol and progesterone in the maternal and umbilical cord blood varied significantly depending on the type of delivery, with higher concentrations being observed in the case of natural delivery. In addition, the highest levels of cortisol were determined in primiparas; however, lowered umbilical cord blood cortisol levels were observed in pregnant women who had participated in antenatal education, regardless of the number of deliveries.