Placental steroid sulphatase deficiency.

Low maternal plasma and urinary oestrogen concentrations in pregnancy are usually indicative of fetal problems, either placental insufficiency or fetal adrenal hypoplasia. Paediatricians, however, should follow obstetricians in becoming increasingly aware that deficiency of placental steroid sulphatase activity, a condition related to X linked ichthyosis, may produce the same abnormalities.