A 28-year-old woman arrived at the Emergency Department (ED) with back pain, bloody vaginal discharge, and reported she had had a positive home pregnancy test but had not received any prenatal care and was unsure of her expected due date. The ED intern evaluating the patient did not suspect active labor and the radiologist remotely reviewing the pelvic ultrasound mistakenly identified the fetal head as a “pelvic mass.” Four hours later, the consulting OB/GYN physician recognized that the patient was in her third trimester and in active labor. She was transferred to Labor and Delivery for labor management, which led to an emergency cesarean section. A neonatal seizure was observed, and brain MRI revealed a perinatal stroke. The Commentary discusses the types of diagnostic errors leading to missed diagnoses and the importance of appropriate supervision of physician trainees.