RESUMO
Placental sulphatase deficiency is a well-recognized disorder recorded in well over 20 cases. Together with fetal adrenal hypoplasia it is a cause of extremely low 24-hour maternal urinary oestriol values with an apparently healthy growing fetus. In both conditions fetal growth, as measured by ultrasound, is satisfactory and other placental function tests, such as plasma human placental lactogen, are normal. Unfortunately gestation is usually prolonged, induction of labour difficult and delivery by Caesarean section common. In the case of fetal adrenal hypoplasia an 'addisonian' crisis can be precipitated by the stress of labour and is a source of considerable concern to the paediatrician. We report here a simple method for the differentiation of these two conditions during the antenatal period