Pregnancy and Neonatal Outcomes in Women Treated for Bowel Endometriosis: A Seven-Year Single-Centre Retrospective Matched Cohort Study

<b>Background/Objectives:</b> Deep infiltrating endometriosis has been linked to worsened maternal and neonatal outcomes. However, reports regarding bowel endometriosis are still scanty. We aimed to evaluate pregnancy, delivery, and newborn adverse outcomes in women after laparoscopic-assisted surgery for bowel endometriosis. <b>Methods</b>: A single-center retrospective cohort study was conducted at a tertiary-care university hospital. From January 2015 to December 2021, pregnant women who were diagnosed and treated for bowel endometriosis were matched using a 1:3 ratio with pregnant women with no history of endometriosis. Patients were matched using the Cox proportional hazards model to determine parity, age, BMI and gestational age-adjusted relative risk (aRR) with a 95% confidence interval (CI). Co-primary outcomes were the incidence of labor abnormalities and cesarean section (CS) rate. Co-secondary outcomes were incidence of complications related to pregnancy, delivery, and newborn. <b>Results</b>: A total of 71 pregnancies among women treated for bowel endometriosis and 213 from healthy controls were included. Patients requiring IVF/ET for getting pregnant were in the bowel endometriosis group relative to controls (43.7% vs. 11.7%; <i>p</i> < 0.001). Increased risk of labor abnormalities was present for bowel endometriosis relative to controls (21.1% vs. 17.4%; <i>p</i> = 0.040; aRR 1.39 [95% CI 1.06-2.05]). Risk of non-cephalic fetal presentation (14.1% vs. 6.1%; <i>p</i> = 0.016; aRR 3.08 [95% CI 2.03-4.68]), CS rate (43.7% vs. 24.9%; <i>p</i> = 0.003; aRR 1.75 [95% CI 1.23-2.49]), and emergent CS rate (19.7% vs. 8.5%; <i>p</i> = 0.009; aRR 2.21 [95% CI 1.55-3.16]) were significantly higher in women treated for colorectal endometriosis compared with controls. Moreover, placenta previa (9.9% vs. 0.0%; <i>p</i> < 0.001; aRR 21.82 [95% CI 2.19-116.40]), second-trimester hemorrhage (5.6% vs. 0.9%; <i>p</i> = 0.017; aRR 6.00 [95% CI 1.12-32.06]), postpartum hemorrhage (15.5% vs. 3.3%; <i>p</i> < 0.001; aRR 4.71 [95% CI 1.90-11.70]), and the need for transfusion during labor (5.6% vs. 0.5%; <i>p</i> = 0.004; aRR 12.00 [95% CI 1.36-105.60]) were increased in treatments vs. controls. Concerning neonatal outcomes, an increased risk for neonatal intensive care unit admission was seen in postsurgical endometriotic women relative to healthy controls (26.0% vs. 6.9%; <i>p</i> < 0.001; aRR 3.75 [2.04-3.86]). <b>Conclusions</b>: Women treated for bowel endometriosis seem more exposed to adverse pregnancy and neonatal outcomes relative to healthy controls. However, additional prospective and comparative studies are needed to validate the available evidence.