Metabolism of C19-delta 5-3 beta-hydroxysteroids in the term human amnion

In human amniotic epithelium isolated from fetal membranes of 2 preterm and 14 full-term fetuses conversion of dehydroepiandrosterone (DHA) into 7-hydroxy-DHA and other highly polar metabolites, to 5-androstenediol and to a lesser extent into androstenedione and testosterone was observed. Similarly, 5-androstenediol was converted by the amniotic epithelium into DHA, highly polar metabolites and also, to a lesser extent, into testosterone and androstenedione. The conversion was higher (with the exception of androstenedione formation) in amnions from preterm deliveries than from the full-term pregnancies. There were no sexual differences. In comparison with the results of our previous study it may be suggested that the formation of delta 4-3-oxo metabolites (testosterone, androstenedione) is maximal in the first trimester, decreases in the second trimester and remains low in the third. In contrast, the oxidation of 5-androstenediol to DHA and the formation of highly polar metabolites is maximal at the end of the second and early in the third trimester and decreases as the delivery approaches.