Abstract
Purpose: Comparison of the activity of 11beta-hydroxysteroid dehydrogenase type 2 in the placenta and the umbilical cord blood cortisol level between caesarean sections with or without uterine contraction and vaginal delivery groups. Cortisol is the main stress hormone responsible for the normal adaptation of the neonate to extrauterine life. The disorders resulting from a dysfunction of the 11β-HSD 2–cortisol system can explain the higher risk of developing diseases in children born by caesarean section. Methods: 111 healthy, pregnant women in singular pregnancy at term of delivery were included into the study. The study comprised 11β-HSD 2 in placental tissue from 49 pregnant women delivering by elective caesarean section and 46 pregnant women delivering by vagina. In 16 cases of the elective caesarean section, regular uterine contractions were declared. Cortisol level was estimated in umbilical cord blood directly after delivery. Results: We found no statistically significant differences in the activity of 11β-HSD 2 in placentas delivered via caesarean sections (29.61 on average in elective caesarean sections and 26.65 on average in intrapartum caesarean sections) compared to vaginal deliveries (31.94 on average, p = 0.381), while umbilical cord blood cortisol in the elective caesarean sections group was significantly lower (29.86 on average) compared to the vaginal deliveries (55.50 on average, p < 0.001) and intrapartum caesarean sections (52.27 on average, p < 0.001). Conclusions: The model of placental 11β-HSD 2 activity and umbilical cord blood cortisol concentration seems to be significant in conditions of stress associated with natural uterine contractions in labour.
Highlights
Glucocorticoids play a key role in regulating foetal intrauterine growth, affecting the development of the blood vessels in the placenta and controlling the delivery of nutrients to the foetus [1], exerting an influence on the cardiovascular system, metabolism and normal foetal homeostasis [2]
We found no statistically significant differences in the activity of 11β-HSD 2 in placentas delivered via caesarean sections compared to vaginal deliveries, while umbilical cord blood cortisol levels differed significantly across the different modes of delivery
In the case of elective, operative deliveries, the umbilical cord blood cortisol levels were significantly lower (29.86) compared to vaginal deliveries (55.50 on average, p < 0.001) Despite significant positive correlation between umbilical cord blood cortisol and duration of uterine contraction, 11β-HSD 2 was not associated with mode of delivery
Summary
Glucocorticoids play a key role in regulating foetal intrauterine growth, affecting the development of the blood vessels in the placenta and controlling the delivery of nutrients to the foetus [1], exerting an influence on the cardiovascular system, metabolism and normal foetal homeostasis [2]. A normally developing pregnancy is a period of hyperactivity of the HPA axis as well as hypercortisolemia. A gradual increase is found in serum cortisol levels of pregnant women, reaching 3 times higher values in the third trimester compared to non-pregnant women [4]. Low concentrations of cortisol are present during the first two trimesters of pregnancy, with the exception of the period around gestational week 10 when an increase in this hormone is observed due to the activity of the newly formed foetal adrenal gland tissue. In the third trimester of pregnancy, the foetal cortisol concentration rises and reaches peak levels in the perinatal period, caused by the weakened placental metabolism of this hormone and its increased synthesis by the foetal adrenals [5]. The elevated cortisol values during pregnancy exert an anti-inflammatory and catabolic effect both in the pregnant woman and the foetus
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