Original Article: PDF OnlyPlasma Levels of Immunoreactive β-Endorphin and Adrenocorticotropic Hormone During Labor and DeliveryFETTES, IVY PhD, MD; FOX, JOEL MD; KUZNIAK, SANDY BSc; SHIME, JERRY MD; GARE, DOUG MDAuthor Information From the Departments of Medicine and Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada. Obstetrics & Gynecology: September 1984 - Volume 64 - Issue 3 - p 359-362 Free Abstract β-endorphin and adrenocorticotropic hormone (ACTH) are derived from the same precursor protein,13 and the plasma levels of β-endorphin and ACTH are thought to be representative of the pituitary secretion of these peptides. Simultaneous measurments of immunoreactive β-endorphin and ACTH were done on plasma samples from pregnant women at term and found to be normal, but a significant increase was observed during the stress of labor. Simultaneous measurement of immunoreactive β-endorphin and ACTH in the umbilical vein at time of vaginal delivery demonstrated elevated levels of both peptides. The newborn also demonstrated an increased ratio of β-endorphin to ACTH, of which the role is uncertain at present. © 1984 The American College of Obstetricians and Gynecologists
