Objectives: Women diagnosed with complete hydatidiform molar pregnancy are at 15% to 28% risk of developing persistent gestational trophoblastic neoplasia (GTN) requiring further management with chemotherapy. Our objective was to develop human chorionic gonadotropin (hCG) criteria that establish a patient's risk of developing persistent GTN or achieving remission from their baseline risk within a few weeks of molar evacuation.
Methods: We used a database from the New England Trophoblastic Disease Center to analyze hCG levels from 1,029 women with complete molar pregnancies. We conducted a retrospective cohort study using data from 1973 to 2001.
Results: Women whose hCG level declined below 50 mIU/mL during their follow-up were found to be at no more than 1.1% risk for developing persistent GTN, irrespective of when this level was reached. Women whose hCG levels was below 200 mIU/mL in the fourth week after evacuation (59.8% of all women), or below 100 mIU/mL in the sixth week after evacuation (65.8% of all women), had a risk of persistence below 9%. hCG levels above 2,000 mIU/mL in the fourth week after evacuation (13.3% of women) were associated with a 63.8% risk of developing persistent disease.
Conclusion: These data may allow clinicians to evaluate the risk of persistence that their patients with complete molar pregnancy have based on early hCG results after molar evacuation. In the fourth week after molar evacuation, 59.8% of women may be counseled that their risk of developing persistent GTN is substantially reduced from their baseline, whereas 13.3% of women may be warned that their risk of developing persistent GTN is greater than 50%.
Level of Evidence: II-2