Characteristics of b-hCG Regression Curves Following Complete Hydatidiform Mole - Revista Brasileira de Ginecologia e Obstetrícia

Purpose: to construct a b-human chorionic gonadotropin (b-hCG) regression curve following complete hydatidiform mole (CHM) of patients with spontaneous remission, and then compare it to that of CHM patients with gestational trophoblastic tumor (GTT). Also, to compare the b-hCG regression curve of CHM patients followed-up at the Service to the regression curve of other authors1-3. Methods: clinical and laboratory evaluations (serum determinations of b-hCG) were performed on admission and during post-molar follow-up of CHM patients treated at the University Hospital of Botucatu between 1990 and 1998. The result of the serial b-hCG determinations was analyzed using log regression curves. The evolution of the b-hCG regression curve was analyzed and compared between cases of CHM with spontaneous remission and with GTT using a log regression curve, with 95% confidence interval. The log regression curve of the spontaneous remission group was compared to those of other authors1,2. Individual log curves for each patient were constructed and classified according to the four curve types (I, II, III, and IV) proposed by Goldstein³ for post-molar follow-up. Results: sixty-one patients received complete post-molar follow-up, 50 (82%) showing spontaneous remission and 11 (18%) developing GTT. In the group of patients with CHM and spontaneous remission, the time to return to normal b-hCG levels after mole emptying was 20 weeks. The patients who developed GTT showed early deviation from normal b-hCG regression curve 4 to 6 weeks after mole emptying. These patients received chemotherapy normally starting during the 9th post-mole emptying week. Conclusions: the regression curve of post-CHM b-hCG in patients with spontaneous remission showed a log-exponential decline similar to that observed by other authors1,2, but different from that of CHM patients who developed GTT. Three types of b-hCG regression curves similar to Goldstein’s³, I, II, and IV, were identified, as well as two other different types: V (normal regression) and VI (abnormal regression).