Obstetric outcomes after general anaesthesia for acute intra-abdominal pathology during pregnancy in a non-university teaching hospital: a retrospective cohort study

Background: Non-obstetric surgery during pregnancy is required in approximately 0.4–1% of pregnant women and has been associated with adverse obstetric outcomes, such as preterm labour and low birth weight. However, these data originate from secondary and tertiary hospitals usually treating high-risk populations, hence potentially overestimating both incidence and risk. Objectives: To analyse the risk of adverse obstetric outcomes after general anaesthesia for acute intra-abdominal pathology during pregnancy in a non-university teaching hospital. Design: Retrospective cohort study. Setting: Non-university teaching hospital. Methods: Women delivering in 2000-2023 were retrospectively identified from surgical and birth registries. Exposed women received general anaesthesia during pregnancy for laparoscopy or laparotomy for appendicectomy, adnexal pathology, cholecystectomy, or diagnostic procedures. Unexposed women lacked this exposure. Inverse probability of treatment weighting was applied to mitigate confounding by maternal age and parity. Main Outcome Measures: The primary outcome was gestational age at delivery. Secondary outcomes included the incidence of surgery, birth weight, and the risk of preterm delivery, low birth weight, and caesarean section. Results: The study included 47 exposed and 470 unexposed women. Most exposed patients (96%) underwent a single anaesthetic exposure of 54 ± 23 minutes (mean ± standard deviation). For the primary outcome, no significant difference was observed (weighted mean difference: –0.48 weeks, 95% CI: –0.99 to 0.04; p = 0.0686). For the secondary outcomes, the unexposed group had a significantly lower risk of preterm delivery (weighted absolute risk reduction: 14.6%, 95% CI: 1.0–28.2%; p = 0.0359), however, significance was lost in sensitivity analysis. Other secondary outcomes did not differ significantly. 0.31% of patients undergoing intra-abdominal surgery in the study centre were pregnant. Conclusions: This study found no robust evidence linking general anaesthesia for acute intra-abdominal pathology during pregnancy to adverse obstetric outcomes.