Outcome of pregnancies occurring within 1 year of hydatidiform mole.

Objective: To determine the outcome of subsequent pregnancies in patients with partial or complete molar pregnancy who conceive before completing the recommended hCG follow-up of at least 6 months.
Methods: Retrospective record review of patients with partial or complete mole who conceived before the standard gonadotropin follow-up of 6 months was completed during 1980-1998.
Results: Sixty-seven patients with molar pregnancy who conceived before completion of hCG follow-up were identified. Thirty-five (52.2%) patients had a prior partial mole, and 32 (47.8%) had a prior complete mole. The mean interval from first achieving undetectable hCG level to new pregnancy was 3.1 and 3.4 months in patients with partial and complete mole, respectively. Eleven patients underwent elective termination, and 12 were lost to follow-up. Of the remaining 44 patients, 33 (75.0%) had live births, 10 had spontaneous abortions, and one had an ectopic pregnancy. A viable pregnancy outcome was achieved in 20 (83.3%) of 24 patients with partial mole and 13 (65.0%) of 20 patients with complete mole. None of the patients developed any evidence of postmolar persistent gestational trophoblastic tumor. None of the live births had any detectable fetal anomalies.
Conclusion: The risk of persistent tumor is low and reproductive outcome is favorable once undetectable hCG levels are achieved. Pregnancies occurring before the completion of recommended hCG follow-up may be allowed to continue under careful surveillance.