Summary
The activity of the hypothalamo-pituitary adrenal axis was examined, by measuring
the levels of immunoreactive (IR) corticotropin-releasing hormone (CRH), adrenocorticotropin
(ACTH) and cortisol (F) in human plasma during normal pregnancy and after delivery
with or without complications and during normal postpartum using a specific RIA.
The level of IR-CRH in maternal plasma increased progressively during pregnancy, increased
further at delivery and declined rapidly to the non-pregnant level on the 1st day
postpartum. The level of IR-F in maternal plasma also increased progressively during
pregnancy, increased further at delivery, but decreased slowly postpartum, not returning
to the non-pregnant level within 5 days. Significant correlations were found between
the level of IR-CRH and IR-ACTH, IR-CRH and IR-F, and IR-ACTH and IRF in maternal
plasma both during pregnancy and after delivery.
It is noteworthy that the concentration of IR-CRH in the maternal plasma at delivery
was higher in multiple pregnancy than in normal pregnancy, and that the level of IR-CRH
in the umbilical cord in uncomplicated cases was much lower than that in the maternal
plasma, and was significantly lower than those in the umbilical cord plasma in cases
of asphyxia, IUGR or premature delivery. The level of IR-F, not IR-CRH and IR-ACTH,
at normal vaginal delivery was significantly higher than that at elective cesarean
section.
On these results, we investigated the feto-maternal-hypothalamo-pituitary adrenal
axis during pregnancy and delivery, in which CRH plays an important role.
Key-Words
Hypothalamo-Pituitary Adrenal Axis - Pregnancy - Corticotropin-Releasing Hormone (CRH)
- Adrenocorticotropin (ACTH) - Cortisol (F)
