Steroid metabolism during pregnancy and in the newborn.

Studies were designed to elucidate the origin of estetrol during late human pregnancy. 3H-15alpha-Hydroxyestradiol and 14C-estradiol were injected into the fetus and in another study these same substrates were injected into the maternal circulation. In a third study 3H-15alpha-hydroxyandrostenedione and 14C-estradiol were injected into the fetus. From the maternal urine the following metabolites were isolated: estriol, containing 14C only and 15alpha-hydroxyestrone, l5alpha-hydroxyestradiol and estetrol all containing both labels. From the isotope content of these metabolites it was concluded that estetrol is derived from estradiol only partially via 15alpha-hydroxyestradiol. [...]Une recherche a été entreprise afin d'étudier l'origine de l'estétrol durant le dernier trimestre de la grossesse chez la femme. Dans une première expérience, le l5alpha-hydroxyestradiol-3H et l'estradiol-14C ont été injectés chez le fetus. Dans une autre expérience ces mêmes substrats furent injectés à la mère. Lors d'une troisième expérience la 15alpha-hydroxyandrostènedione et l'estradiol-14C ont été injectés à un fetus. A la suite de ces experiences l'estriol seulement marqué au Carbone 14, la 15-hydroxy-estrone, le 15alpha hydroxyestradiol et l'estetrol tous doublement marqués furent isolés de l'urine de la mère. [...