The effect of segmental epidural analgesia on maternal ACTH, cortisol and TSH during labour.

Maternal plasma ACTH, cortisol and TSH concentrations were determined during the course of the induced labours of 20 normal parturients. Alternate mothers were given segmental epidural analgesia for pain relief during the first stage of labour. The remaining parturients served as controls. The ACTH level rose in same way in both groups, reaching its peak at the moment of delivery and decreasing rapidly thereafter. Cortisol secretion reached its maximum during the first stage of labour in the moment of delivery. After delivery the cortisol level decreased more rapidly in the epidural group tha. in the control gro,p. Umbilical venous cortisol concentration was the same in both groups. The maternal TSH level did not change significantly during labour in either group.