SUN-374 Management of Congenital Adrenal Hyperplasia in Pregnancy with Female Fetus

Introduction: Dexamethasone (dex) crosses placenta, suppresses fetal ACTH and reduces level of adrenal androgens in fetus with Congenital Adrenal Hyperplasia (CAH). This reduces virilization of female genitalia and its associated risk of emotional distress and need for reconstructive surgery (1). As organogenesis begins at 6 weeks, pre-natal treatment with dex must be started at 6-7 weeks. However, dex is a category C drug and its use is associated with birth defects, reduced birth weight and decreased cognitive function. Clinical Case:A 30-year-old African American (AA) female at 25 weeks gestation was referred to the Endocrine clinic after being lost to follow up for two years for management of 21-hydroxylase deficient CAH-virilizing type in pregnancy. She recalls being diagnosed with CAH around 2 years of age, was followed by Pediatric Endocrinology and has been maintained on oral steroids. Her birth and family history are unknown as she is adopted. She had clitoromegaly and underwent clitoral reduction surgery at 8yrs of age. She has had extensive hirsutism but denied having menstrual irregularities or problems conceiving besides one miscarriage at 10 weeks gestation, 1 year prior to current pregnancy. She had an uncomplicated pregnancy 3 years ago and delivered a boy whose genetic testing was negative for CAH. She was on prednisone then. She had history of non-compliance and was switched to dex 0.75 mg nightly 2 years ago. She did not follow with up Endocrine for the last 2 years as she was asymptomatic and had her dex refilled by primary care physician and had been taking it regularly. Her current pregnancy had been going well. She now has a female fetus with a different AA partner who does not have personal or family history of CAH. Genetic testing of father to see if he is a carrier could not be done, and patient refused chorionic villous sampling to determine fetus’ risk of CAH. Given unknown risk of female fetus having CAH and potential complications of dex, we recommended switching to hydrocortisone (HC) 10mg BID. Clinical Lesson: Endocrine society recommends against treatment of CAH in pregnant women with dexamethasone except in cases of prenatal treatment of CAH of female fetuses which is performed at few selected centers (2). In the case above, patient conceived on dex and continued dex for first 25 weeks of her pregnancy until seen by Endocrinologist. By that time, acute decision-making period was over. Female fetus whose risk of CAH is unknown was exposed to dexamethasone and has possible risk of developing complications. This case emphasizes importance of correct steroid treatment early in pregnancy, multidisciplinary approach in management of such patients and importance of endocrine follow up for all CAH patients especially those of reproductive age. (1) Clin Endocrinol (Oxf). 2010 Oct;73(4):436-44 (2) J Clin Endocrinol Metab. 2018 Nov 1;103(11):4043-4088