Endocrine Abstracts

Introduction: The prenatal treatment of Congenital Adrenal Hyperplasia (CAH) with Dexamethasone (Dex) is effective at minimising virilisation in affected females. Treatment is initiated with Dex at 20 mcg/kg per day (max 1.5 mg/day) as soon as pregnancy is confirmed and continued to term in affected females only. There are concerns regarding neurocognitive difficulties in children exposed to prenatal Dex, but no reports of late intra-uterine deaths (IUD) attributed to prenatal Dex.

Case studies: We report 2 cases over a 6 year period, where women with previous CAH affected children received prenatal Dex from 6 weeks gestation for the duration of the pregnancy. Case 1: A 38 year old woman received Dex 1.5 mg/day. Normal fetal growth on ultrasound (USS) was documented at 36 weeks. At 39+6 weeks she had a spontaneous rupture of membranes, but no fetal heart beat and thus an IUD was confirmed. The birth weight was 2570 gms (−1.9 SDS). Placental histopathology revealed chronic villitis and it is possible that Dex could have had an influence on any underlying pathology. Case 2: A 34 year old women received Dex 1.0 mg/day. A normal USS at 34 weeks was documented. At 40+11 weeks; the day prior to planned delivery there were reduced fetal movements and an IUD was confirmed. The birth weight was 2150 gms (−2.95 SDS), with asymmetrical IUGR. Placental histopathology was unremarkable. In both cases no maternal side effects of DEX were noted, a congenital infection screen was negative and the deceased offspring had normal female genitalia.

Conclusions: Although the rate of late gestation IUD is low, these two cases raise concern that the use of Dex during pregnancy for CAH may be associated with an increased rate. This should be carefully considered when counselling families regarding prenatal treatment with additional vigilance maintained during pregnancy, and serious consideration given to offering delivery at 38 weeks.