The impact of previous cesarean section (C/S) on the risk for post-molar gestational trophoblastic neoplasia (GTN)

To investigate the relationship between previous cesarean section (C/S) and risk for post-molar gestational trophoblastic neoplasia (GTN).

Data from patients who were treated for hydatidiform moles between 1995 and 2016 were retrospectively reviewed. Patient age, gravidity, parity, abortion history, gestational age, pretreatment beta-human chorionic gonadotropin (HCG), previous molar pregnancy, clinical symptoms, enlarged uterus, theca lutein cyst, type of GTN, World Health Organization risk score, chemotherapy, and mode of delivery were recorded. Hazard ratios (HR) and 95% confidence intervals (CI) for variables associated with the occurrence of post-molar GTN and invasive mole were estimated by univariate and multivariate Cox proportional hazards models.

From 1995 to 2016, 182 patients were diagnosed with molar pregnancy and underwent treatment. Patients with previous C/S (C/S group) had higher age (37.0 vs 32.8. p = 0.004), gravidity (3.1 vs 2.0, p < 0.001), and parity (1.6 vs 0.9, p < 0.001) than patients without previous C/S (non-C/S group). Post-molar GTN (43.5 vs 26.5%, p < 0.001), invasive mole (21.7 vs 3.7%, p < 0.001), hysterectomy (28.3 vs 6.6%, p < 0.001), and chemotherapy (45.7 vs 28.7%, p = 0.03) were more frequent in the C/S group. In multivariate analysis, independent risk factors for post-molar GTN were previous C/S (HR 5.1, 95% CI 2.1-12.7), abortion history (HR 6.3, 95% CI 2.5-15.6), and pretreatment β-hCG (HR 1.3, 95% CI 1.1-1.6).

In this study, C/S was a strong risk factor for occurrence of post-molar GTN and invasive mole. Aggressive treatment, such as multi-agent chemotherapy or hysterectomy, can be considered for hydatidiform moles in patients with a C/S history.