“… Ampicillin administered for three days to four pregnant women caused a decrease in the urinary … of estrogens, pregnanediol, pregnanolone, 6-oxygenated progesterone metabolites, 17-oxosteroids, 17-oxogenic steroids, dehydroepiandrosterone ( DHA ), 16α-OH DHA and some of its metabolites; plasma progesterone … only in one of these women was also lowered.”