Low risk of relapse after achieving undetectable hCG levels in women with partial molar pregnancy

OBJECTIVE: We evaluated the risk of gestational trophoblastic neoplasia (GTN) for women with partial molar pregnancy whose human chorionic gonadotropin (hCG) levels fall spontaneously to undetectable levels using a sensitive hCG assay. METHODS: We analyzed data from the New England Trophoblastic Disease Center to estimate the risk of GTN among 284 women with partial molar pregnancy and at least 6 months of gonadotropin follow-up. RESULTS: None of the 238 women with complete gonadotropin follow-up and a spontaneous decline in serum hCG levels to undetectable levels subsequently developed GTN (95% confidence interval 0-1.6%). CONCLUSION: If these results are replicated at other institutions with longstanding experience managing partial molar pregnancies, it may be reasonable to abbreviate clinical follow-up for women with partial molar pregnancy whose serum hCG levels spontaneously decline to an undetectable level.