URINARY EXCRETION OF OESTRONE, OESTRADIOL-17β AND OESTRIOL IN PREGNANCIES COMPLICATED BY STEROID SULPHATASE DEFICIENCY

Abstract

SUMMARY: The urinary excretion of oestrone, oestradiol-17β and oestriol was measured by gas–liquid chromatography in 24 h urine specimens, collected after 34 weeks of gestation from each of eight women whose pregnancies were complicated by steroid sulphatase deficiency and from each of 21 pregnant women without this complication. Mean (±s.d.) values μmol/24 h, sulphatase deficient; normal) were: oestrone, 0·7 ± 0·2; 2·5 ± 1·3; oestradiol-17β, 0·5 ± 0·2; 1·6 ± 0·5: oestriol, 2·0 ± 0·9; 54·4 ± 19·9. Thus, mean oestrone and oestradiol-17β excretions were only 30% of normal whilst mean oestriol excretion was reduced by more than 90%. Consequently, the mean ratio of urinary oestriol/(oestrone + oestradiol-17β changed from 13·7 ± 2·3 in normal pregnancy to 1·6 ± 0·6 in pregnancies complicated by steroid sulphatase deficiency. The greater fall in oestriol excretion in this condition, in comparison with that of oestrone and oestradiol-17β, emphasizes the importance of conjugated 16-oxygenated C₁₉ steroids in the biosynthesis of oestriol in human pregnancy. The change in the relative proportions of the three urinary oestrogens implies that in the precursor pool of normal pregnancy the concentration of 16-oxy-C₁₉ steroids relative to that of the 16-deoxy-C₁₉ steroids, is much greater in the sulphate fraction than it is in the unconjugated fraction. The measurement of the urinary oestriol/(oestrone+oestradiol-17β) ratio may have the potential to make it possible to distinguish, before birth, between pregnancies complicated by steroid sulphatase deficiency and those with foetal adrenal hypoplasia.