THE RELATIONSHIP OF HUMAN UMBILICAL ARTERIAL AND VENOUS PLASMA LEVELS OF CORTICOSTEROIDS TO GESTATIONAL AGE

Abstract

The role of the foetal adrenal cortex in the initiation of parturition in the sheep is well established; however the evidence for a similar role by the human foetal adrenal is circumstantial and based upon the association of prolonged gestation with foetal adrenal hypoplasia (Anderson, Laurence & Turnbull, 1969; Roberts & Cawdery, 1970) and of premature delivery with foetal adrenal hyperplasia (Anderson, Laurence, Davies, Campbell & Turnbull, 1971). There is no information concerning changes in levels of corticosteroids in the human foetus in late pregnancy and the present study was undertaken in order to examine the relationship of umbilical cord arterial and venous plasma concentrations of corticosteroids at the time of delivery to gestational age of the foetus and type of labour. Matched samples of umbilical cord arterial and venous blood were collected during December 1971 — January 1972. Plasma levels of corticosteroids were determined by a competitive protein-binding technique (Murphy,