Normal human chorionic gonadotropin regression curves in uneventful postmolar patients.

Objective: To review current follow-up measures of human chorionic gonadotropin (hCG) in uneventful postmolar patients, and to evaluate criteria for initiating chemotherapy.

Study Design: Between 1993 and 2011 hCG data from 395 patients with uneventful complete moles (CMs) (195 patients) and partial moles (PMs) (205 patients) were obtained at 4 hospitals in Japan. All patients had been followed regularly at various intervals based on the preceding hCG titers and normal hCG regression curve.

Results: All patients achieved hCG normalization spontaneously (range, 3.1-29.7 weeks). Approximately half of the patients with CM and PM had attained an undetectable hCG level at 9.3 and 8.3 weeks after evacuation of mole, respectively. The reconstructed normal hCG regression curve consisted of hCG levels of 1,000 mIU/mL at 5 weeks, 100 mIU/mL at 8 weeks and nondetectable hCG levels at 24 weeks. Plotting preceding hCG titers on this hCG regression curve, the intervals of visits to measure hCG were changing, and the real number of visits was significantly fewer than that of recommended weekly measurement of hCG (p<0.0001).

Conclusion: The use of the present hCG regression curve after evacuation of a molar pregnancy can aid in estimation of the risk of developing gestational trophoblastic neoplasia, especially in women who have suboptimal compliance and follow-up.