Appendectomy during pregnancy: rates, safety, and outcomes over a five-year period. A hospital-based follow-up study

Objective: To assess the outcome of pregnancy after appendectomy, the mode of surgery used, appendectomy rates and complications. Design: A prospective cohort study of pregnant women undergoing appendectomy. Setting: All appendectomies at South Stockholm General Hospital, December 2015 to February 2021. Population: Pregnant women undergoing appendectomy. Methods: Data on preoperative imaging, surgical method, intraoperative findings, microscopic findings, hospital stay, pregnancy, and 30-day complications were prospectively recorded in a local appendectomy register. Results: During the study period, 50 pregnant women underwent appendectomy of 38 199 women giving birth. During the same period 793 non-pregnant women underwent appendectomy and served as controls. No differences in preterm delivery (4.5% vs. 5.6%), small-for-gestational age (2.3% vs. 6.2%), or mode of delivery (cesarean delivery 18.2% vs. 20.4%) were observed between pregnant women with or without appendectomy. There were no cases of perforated appendix in the second half of pregnancy. However, women with gestational age > 20 weeks more frequently had an innocent appendix compared to those operated < 20 gestational weeks (4/11 vs. 2/39, p = 0.005). Laparoscopic surgery was used in 92% of appendectomies < 20 weeks gestation. The appendectomy rate was three times lower during the second half of pregnancy. Conclusion: Appendicitis in pregnancy is not a threat as long as surgery is conducted as soon as possible. Although a low threshold for surgery may increase the risk of finding an innocent appendix, this is outweighed by the lower risk for perforation and serious adverse events such as fetal loss or preterm delivery.