BIOCHEMICAL AND CLINICAL OBSERVATIONS IN A PREGNANCY WITH PLACENTAL SULPHATASE AND OTHER ENZYME DEFICIENCIES

Abstract

SUMMARY The oestrogen excretion of a pregnant woman, subsequently shown to have placental sulphatase deficiency, was only 1‐2 mg/24 hr, whereas pregnanediol and 17‐oxogenic steroid excretion were within the normal ranges. Plasma concentrations of oestradiol‐17β, progesterone, 17α‐hydroxyprogesterone, 11β‐hydroxycortico‐steroids and corticosteroid‐binding globulin were subnormal. Placental sulphatase activity in vitro towards the sulphates of DHA, pregnenolone and oestrone was negligible, although extracts of a normal placenta showed high activity under identical conditions. The activities of placental enzymes concerned with metabolism of non‐conjugated steroids (3β‐hydroxysteroid dehydrogenase‐isomerase for DHA and for pregnenolone, aromatase complex and 17β‐hydroxysteroid for oestradiol‐17β) were less than those of a normal placenta but were not diminished as severely as sulphatase activity. Satisfactory uterine contractions were achieved during infusion of prostaglandin E 2 or Syntocinon but the cervix failed to dilate. A healthy male infant (3330 g) was delivered at term by Caesarean section. From the evidence obtained during the study of this patient it appears that (i) the presence of appropriate non‐conjugated substrates may be required for the induction of placental enzymes concerned with the metabolism of free steroids; (ii) measurement of maternal 17‐oxogenic steroid excretion may help to distinguish patients with placental sulphatase deficiency from those whose fetus has adrenal hypoplasia; (iii) further investigations, possibly involving steroid replacement therapy, are required to identify which, if any, of the alterations in plasma steroid concentrations are associated with the failure to achieve cervical dilatation.