Endometriosis and Adverse Pregnancy Outcomes: A Nationwide Population-Based Study

Endometriosis is a major cause of infertility, and considering its pathophysiology, it is expected to affect pregnancy outcomes as well. This study aimed to evaluate whether endometriosis is associated with adverse pregnancy outcomes after successful conception. Data from singleton pregnancy deliveries between January 2014 and October 2019 were obtained from the Korean Health Insurance Review and Assessment Service database. We compared the clinical characteristics and adverse pregnancy outcomes of women with and without endometriosis. A total of 1,251,597 pregnant women were enrolled; of these, 32,951 (2.6%) were assigned to the endometriosis group. Women with endometriosis had significantly more adverse pregnancy outcomes than those without endometriosis. Adverse pregnancy outcomes associated with endometriosis included preterm labor, preterm birth, preeclampsia, fetal growth restriction, placenta previa, placental abruption, antepartum and postpartum hemorrhage, and stillbirth. This study also showed an increased risk of postpartum hemorrhage, blood transfusion, uterine artery embolization, and cesarean hysterectomy in the endometriosis group compared to the non- endometriosis group. The cesarean delivery rate was significantly higher in the endometriosis group than in the non-endometriosis group, even after excluding cases of antenatal obstetric complications that could increase the risk of cesarean delivery. Women with endometriosis not only have difficulty conceiving, but also have a significantly higher risk of adverse pregnancy outcomes.