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

Introduction Appendicitis is the most common acute abdominal complication during pregnancy. If appendix perforation occurs there is an increasing risk of preterm delivery and other pregnancy complications. Objective To assess the outcome of pregnancy after appendectomy, the mode of surgery used, appendectomy rates, and complications. Methods A prospective cohort study of pregnant women with, or without, appendectomy at South Stockholm General Hospital, December 2015 to February 2021 in a setting where pregnant women are prioritized for surgery and laparoscopic surgery was standard of care in first half of pregnancy. 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. A non-pregnant control group was gathered comprising women of fertile age in the same study interval. Results During the study period 50 pregnant women, of whom 44 gave birth, underwent appendectomy of 38 199 women giving birth. There were no differences between women with or without appendectomy in proportion of preterm delivery (4.5% vs. 5.6%), small-for-gestational age (2.3% vs. 6.2%), or Cesarean delivery (18.2% vs. 20.4%). The rate of appendix perforation was 19% in non-pregnant control group compared to 12% among pregnancy. There was no case of perforated appendix in the second half of pregnancy. However, women with gestational age > 20 weeks more frequently had an unaffected appendix compared to those operated <= 20 gestational weeks (4/11 vs. 2/39, p = .005). Laparoscopic surgery was used in 97% of non-pregnant control group, 92% of appendectomies <= 20 weeks gestation, and in 27% >20 weeks. As compared to first half, the appendectomy rate was three times lower during the second half of pregnancy. Pregnant women had priority for surgery < 6 h compared to < 24 h among non-pregnant women, this resulted in a shorter time-to-surgery among pregnant women (p < .001) Conclusion Routine laparoscopic surgery and time priority for pregnant surgery is associated with a low risk of perforation, preterm birth and other complications. However, a low threshold for surgery may increase the risk of a negative exploration.