Prognostic characteristics of serum human chorionic gonadotropin titer regression following molar pregnancy.

The postevacuation serum beta human chorionic gonadotropin (hCG) regression curves of 77 women with hydatid moles were analyzed from the perspective of refining the criteria for diagnosis of gestational trophoblastic neoplasia. Forty-nine patients (64%) demonstrated a spontaneous, progressive fall in serum hCG titers to levels nondetectable by radioimmunoassay within 15 weeks. The regression curves of the remaining 28 patients exhibited a plateau or rise in titer, usually during the first 6 weeks after evacuation. Analysis of the 2 groups demonstrates a statistically significant difference in regression curves that permits early identification of the patient with gestational trophoblastic neoplasia. The significance of these curves is discussed.