Women With a Partial Mole During Their First Pregnancy and Diagnosed Earlier in Gestation Are at Increased Risk of Developing Gestational Trophoblastic Neoplasia

Objective The aim of this study is to identify factors associated with gestational trophoblastic neoplasia (GTN) after partial molar pregnancy. Methods We retrospectively evaluated clinical data from 111 patients with a partial molar pregnancy between 1995 and 2010. Results A total of 111 patients with a partial molar pregnancy were available for analysis. There was no significant difference between patients who did and did not develop GTN with respect to patient age, parity, history of prior molar pregnancy, presenting signs/symptoms, uterine size greater than gestational age, clinical diagnosis, preevacuation sonogram findings, or the preevacuation human chorionic gonadotropin value. Patients who developed GTN had fewer prior pregnancies (median, 2 vs 3; P = 0.02) and were more likely to have had a partial molar pregnancy as their first gestational event (37.1% vs 17.1%; P = 0.03). Among the 35 patients who developed GTN, the median time to diagnosis of GTN was 47 days (range, 25–119 days), and the median human chorionic gonadotropin value at the time of GTN diagnosis was 475 mIU/mL (range, 20–52,630 mIU/mL). All women (100%) who developed GTN had stage I disease, and all patients (100%) had low-risk GTN. All 35 women (100%) were able to achieve remission, and most (85.7%) of these patients received methotrexate as first-line chemotherapy. Conclusions Women with a partial molar pregnancy as their first gestational event and diagnosed earlier in gestation are more likely to develop postmolar GTN.