Review Question - QID 109208

A 27-year-old woman presents for her first prenatal visit at an estimated gestational age of 16 weeks and 4 days by last menstrual period. She is presenting late to prenatal care due to significant anxiety about her pregnancy, as she and her husband had struggled with infertility for several years prior to conceiving. She has had nausea and vomiting for about 2 months, tender and swollen breasts, and cravings for foods she typically does not eat. She took a pregnancy test about 10 weeks ago and was too nervous to read the result immediately. After 24 hours, she saw that it was positive. The patient has a past medical history of bulimia nervosa but has not been symptomatic in 2 years. She also had an appendectomy at age 15 for appendicitis. She is a Ph.D. student and her husband is a physician. Her temperature is 98.5°F (36.9°C), pulse is 75/min, blood pressure is 122/76 mmHg, and respirations are 13/min. The patient’s affect is normal and she is pleasant and excited about her pregnancy. A physical exam is notable for abdominal distension but is otherwise unremarkable. Ultrasound is shown in Figure A, and urine human chorionic gonadotropin is negative in the office. Which of the following is the most likely diagnosis?