A 24-year-old woman presents to the emergency department with left lower abdominal pain and vaginal spotting. She is 7 weeks amenorrhoeic. Serum β-hCG is 2200 mIU/mL. Transvaginal ultrasound shows no intrauterine pregnancy and a small amount of free fluid in the pouch of Douglas. She is hemodynamically stable. What is the MOST appropriate next step?
- A Immediate laparoscopy
- B Administer methotrexate 50 mg/m² IM
- C Repeat β-hCG in 48 hours and repeat ultrasound ✓
- D Uterine curettage to rule out intrauterine pregnancy
Correct answer: C. Repeat β-hCG in 48 hours and repeat ultrasound
Explanation
With a β-hCG of 2200 mIU/mL and no intrauterine pregnancy on transvaginal ultrasound, the patient is below the discriminatory zone (typically 1500–3000 mIU/mL), meaning an intrauterine pregnancy may not yet be visible. In a hemodynamically stable patient without definitive diagnosis of ectopic pregnancy, the appropriate step is serial β-hCG measurement in 48 hours. A rise of less than 53% in 48 hours suggests a failing or ectopic pregnancy and helps direct management.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.