Review Question - QID 210468

A 5-day-old newborn is brought to the pediatrician by her parents for new-onset vaginal bleeding. When the patient’s father was changing her diaper, he noticed blood and white vaginal discharge. The patient was born at 39 weeks to a G1P1 mother who has well-controlled type 1 diabetes. The pregnancy and the vaginal delivery were unremarkable. Apgar scores were 8/9. The patient is breastfeeding well. The patient’s temperature is 99°F (37.2°C), blood pressure is 70/48 mmHg, pulse is 134/min, and respirations are 38/min with an oxygen saturation of 98% on room air. She has lost 5% of her weight since birth. Physical examination notes neonatal acne, enlarged breasts, swollen labia, white vaginal discharge, and evidence of blood in the vaginal opening. Which of the following is the most likely cause of the patient’s symptoms?