Effect of intravenous or intra-amniotic injection of dehydroepiandrosterone sulphate on oestrogen levels in urine and serum in late pregnancy with live anencephalic foetuses.

Dehydroepiandrosterone sulphate (DHAS) was injected intravenously or intra-amniotically into eight volunteers carrying live anencephalic foetuses (including one microcephalic foetus). Urinary and unconjugated serum oestrone, oestradiol and oestriol were measured before and after DHAS administration. In seven pregnant women with live anencephalic foetuses the urinary excretion of oestriol was very low, and the ratio of oestriol to oestrone + oestradiol was much less than that during normal pregnancy. Increases of urinary oestrone and oestradiol but no significant change in the ratio of oestriol to oestrone + oestradiol were observed 24 h after i.v. administration of DHAS to five patients. In three patients, between 1 and 12 h after i.v. administration of DHAS (100-200 mg), the concentrations of serum oestrone, oestradiol and oestriol increased to 13-5, 6-8 and 3-1 times the control values, respectively. After injection of DHAS (200 mg) intra-amniotically into two patients, the urinary excretion of all three oestrogens increased much more on day 2 than on day 1, and the ratio of urinary oestriol to oestrone + oestradiol rose greatly. On the other hand, the concentrations of unconjugated serum oestrogens in these patients increased progressively between 1 and 12 h or more after DHAS administration, and the maximal level of serum oestriol was 9-8 times the control value while those of oestrone and oestradiol were 4-6 times and 5-0 times the control values, respectively. These results suggest that in late human pregnancy DHAS in the circulation of the mother is converted to oestriol largely via the phenolic pathway (DHAS leads to oestrone leads to oestriol), whereas DHAS circulating within the foeto-placental compartment is converted to oestriol via both the phenolic and the neutral intermediates.