Background: Gestational trophoblastic disease (GTD) develops from abnormal cellular proliferation of trophoblasts following
fertilization and is categorized as either an hydatidiform mole (HM) or a gestational trophoblastic neoplasia (GTN).
Objective: To analyze the clinical characteristics, incidence and treatment outcomes of GTD at Rajavithi Hospital.
Material and Method: Medical records of women diagnosed with GTD at Rajavithi Hospital from January 1, 2001 to
December 31, 2010 were retrospectively reviewed. Disease diagnosis, treatment and follow-up data were analyzed.
Results: A total of 329 cases of GTD were reviewed. HM was diagnosed in 167 patients (incidence 2.32 per 1,000 deliveries);
26 patients were lost to follow-up; and 49 of the remaining 141 patients (34.8%) developed post-molar GTN. In multivariable
analysis, uterus >16 week size and pre-treatment human chorionic gonadotropin (hCG) level >250,000 mIU/mL were the
significant risk factors for developing post-molar GTN. Of 162 patients with GTN (incidence 2.25 per 1,000 deliveries), 15
patients were lost to follow-up, and 116 patients, 29 patients and 2 patients were classified as having low-risk GTN, high-risk
GTN and placental site trophoblastic disease respectively. The overall survival rate in the low-risk group was 100% whereas in the high-risk group it was 86.2%. A modified WHO prognostic score of more than five was the significant risk factor for developing resistant GTN.
Conclusion: GTD treatment at Rajavithi Hospital showed excellent clinical outcomes. Uterus >16 weeks size and pretreatment hCG >250,000 mIU/mL were the significant risk factors for developing post-molar GTN in HM patients. Classifying GTN patients into low- and high-risk groups was useful in planning treatment and counseling.

Keywords: Gestational trophoblastic disease, Hydatidiform mole, Gestational trophoblastic neoplasia