Objective: To determine whether mode of delivery is associated with the endocrine stress response in mother and child.
Design: Prospective observational study.
Setting: Tertiary care centre, University hospital.
Population: A total of 103 nulliparous women with uncomplicated singleton pregnancies at term undergoing either spontaneous labour for vaginal delivery or delivering by caesarean section without labour. Thirty women delivered vaginally without any pain relief, 21 women delivered vaginally with epidural anaesthesia, 23 women had ventouse extraction and 29 women underwent caesarean section with epidural analgesia.
Methods: After delivery, maternal and umbilical cord blood was collected for determination of different stress-associated hormones.
Main outcome measures: Concentrations of epinephrine (EP), norepinephrine (NOR), adrenocorticotropic hormone (ACTH), cortisol (CORT), prolactin (PRL), corticotropin-releasing factor and beta-endorphin (BE).
Results: Caesarean section was associated with significantly lower maternal concentrations of EP, NOR, ACTH, CORT, PRL and BE and lower newborn levels of EP, NOR and CORT compared with all other modes of delivery. Concentrations of EP, ACTH and BE differed significantly in newborns delivered by normal vaginal delivery, vaginal delivery with epidural anaesthesia and ventouse extraction.
Conclusions: The mode of delivery and analgesia used during birth are associated with maternal and fetal endocrine stress responses.