Undervirilized male infant with in utero exposure to maternal use of high dose antifungal therapy

Background Antifungals act on fungal sterols structurally similar to human cholesterol. Ketoconazole reversibly suppresses steroidogenesis by inhibiting cytochrome P450 enzymes and interferes with dihydrotestosterone (DHT) activity by binding to the androgen receptor. Hypospadias was reported in infants exposed to nystatin in utero. Case presentation A male infant exposed to antepartum nystatin presented with severe under-undervirilization and transient adrenal corticosteroid abnormalities. He was born in USA at 31 weeks gestation to a mother treated with vaginal Polygynax capsules (nystatin-100,000 international units, neomycin sulphate-35,000 international units and polymyxin B-35,000 international units) for vaginal discharge in the Ivory Coast. She used approximately 60 capsules between the first trimester until delivery. The infant was born with micropenis, chordee, perineo-scrotal hypospadias and bifid scrotum with bilaterally palpable gonads. The karyotype was 46,XY. No Mullerian structures were seen on ultrasound. Serum 17-hydroxyprogesterone (17 OHP) on newborn screening was high (304 ng/ml, normal Conclusions We report severe undervirilization in a 46,XY infant born to a mother treated with prolonged and high dose nystatin during pregnancy. This presentation suggests that prolonged antepartum use of high dose nystatin could lead to severe but transient defects in androgen synthesis and/or action possibly by acting as an endocrine disruptor. Further studies are warranted to confirm this finding. Thus, endocrine disruptors should be considered in male newborns with atypical genitalia not explained by common pathologies.