Human Chorionic Gonadotropin Regression Curves after Partial or Complete Molar Pregnancy in Flanders: Are They Different from Regression Curves from the Eighties?

BACKGROUND/AIMS: We updated human chorionic gonadotropin (hCG) regression curves created in the eighties after evacuation of complete and partial molar (CM and PM, respectively) pregnancies using modern hCG assays. We created similar curves for patients in need of chemotherapy (gestational trophoblastic neoplasia [GTN]).

METHODS: A total of 126 patients who were diagnosed with gestational trophoblastic disease from 1990 to 2014 were included. We compared curves from 2 groups, CM and PM, with historical ones. The third group was a comparison of GTN patients receiving first-line chemotherapy and patients in need of a switch of chemotherapy.

RESULTS: The regression curves were comparable to historical ones. According to the latter, mean time to normalization was 14-15 weeks after evacuation. We observed a normalization within 12 (CM) and 12.7 (PM) weeks. In addition, a remarkable but not statistically significant vertical shift (20 IU/L higher) was observed prior to day 60 compared with historical curves. The comparison in GTN patients showed a statistical significant difference, even at day 7.

CONCLUSION: The presented hCG regression curves in the Flemish region were comparable with the ones of the eighties but with a vertical shift, hypothetically due to more sensitive assays. In addition, regression curves in GTN patients receiving chemotherapy can be used to evaluate response.