Obstetric outcomes after medroxyprogesterone acetate treatment for early stage endometrial cancer or atypical endometrial hyperplasia: a single hospital-based study

Background To investigate perinatal outcomes in pregnancy after high-dose medroxyprogesterone acetate (MPA) therapy for early stage endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) and to determine whether pregnancy after MPA therapy is at a higher risk of placenta accreta. Methods Data of 51 pregnancies in 46 women who received MPA therapy for EC or AEH and delivered after 22 weeks of gestation at Keio University Hospital were reviewed. A retrospective matched case–control study was performed to determine the risk of placenta accreta in pregnancy after MPA therapy compared with singleton pregnancies without any history of maternal malignancy treatments. Results The incidence of placenta accreta was higher in the MPA group than in the control group (15.7 vs. 0%, p = 0.0058). However, no differences in other perinatal outcomes were observed between groups. While gestational weeks at delivery in the MPA group were later than those in the control group ( p = 0.0058), no difference in the incidence of preterm delivery was recorded between groups. In the MPA therapy group, the number of patients who underwent ≥ 6 dilation and curettage (D&C) was higher in the placenta accreta group than in the non-placenta accreta group (50.0 vs. 14.0%, p = 0.018). Patients with ≥ 6 D&Cs demonstrated a 6.0-fold increased risk of placenta accreta ( p = 0.043, 95% CI 1.05–34.1) than those receiving ≤ 3 D&Cs. Conclusion Pregnancy after MPA therapy is associated with a high risk of placenta accreta. In cases in which the frequency of D&C is high, placenta accreta should be considered.