A 29-year-old woman presents with vaginal spotting after 6 weeks of amenorrhea.

An empty uterus with β-hCG >1500–2000 IU/L raises concern for a pregnancy of unknown location (PUL), including the possibility of ectopic pregnancy. However, the patient is hemodynamically stable and asymptomatic. In such cases, the best initial step is to repeat serum β-hCG in 48 hours to assess the rise or fall of hCG levels.

Toronto Notes 2023 – Obstetrics, "First Trimester Bleeding":

“If β-hCG >1500 IU/L and no intrauterine pregnancy is visualized on ultrasound, repeat β-hCG in 48 hours to determine rise or decline. A suboptimal rise (less than 66%) suggests ectopic pregnancy.”

MCCQE1 Objectives (Obstetrics > 79-1: Early Pregnancy Complications):

“In a patient with early pregnancy bleeding, the candidate must interpret quantitative β-hCG trends to distinguish ectopic pregnancy, miscarriage, or viable intrauterine pregnancy.”

Immediate administration of methotrexate or invasive procedures such as D&C or laparoscopy are not appropriate until further diagnostic clarification is obtained.

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