To assess how much and on which specialities nonobstetric surgery was performed for pregnant women in Finland during a 21-year period, between 1997 and 2017 and the effect of Finnish guideline about preoperative evaluation affected the amount of surgery during pregnancy. Design: Register-based observational study. Setting: Finnish Medical Birth Register. Population: 1 175 677 pregnancies ending with a singleton birth 1997−2017. Methods: Amount of nonobstetric surgeries, and pregnancy foetal and maternal outcomes in Finland between 1997 and 2017 were searched. Main Outcome Measures: The prevalence of nonobstetric surgery, and proportions of elective and emergency nonobstetric surgery performed during the three trimesters. Results: The prevalence of nonobstetric surgery before the guideline was 0.39%, after the guideline 0.28% and after the first revision 0.39%. The prevalence of elective surgery decreased after the guideline (before 0.15%, after the guideline 0.10% and 0.07% after the first revision), but the prevalence of emergency surgery was highest after the first revision (0.24%, 0.21% and 0.29%). The guideline and the first revision had no impact on the timing of elective surgery; 35% of elective surgery was performed during the second trimester before the guideline, 36% after it and 36% after its first revision. The preterm delivery rate, 9.1%−9.4% of pregnancies with nonobstetric surgery was twofold higher than that of pregnancies without surgery. Conclusion:The prevalence of nonobstetric surgery during pregnancy is low in Finland. The national guideline decreases the prevalence of elective surgery during pregnancy but does not impact the timing of nonobstetric surgery.

Background and objective: Non-obstetric surgery is fairly common in pregnant women. We performed a systematic review to update data on non-obstetric surgery in pregnant women. The aim of this review was to evaluate the effects of non-obstetric surgery during pregnancy on pregnancy, fetal and maternal outcomes. Methods: A systematic literature search of MEDLINE and Scopus was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search span was from January 2000 to November 2022. Thirty-six studies matched the inclusion criteria, and 24 publications were identified through reference mining; 60 studies were included in this review. Outcome measures were miscarriage, stillbirth, preterm birth, low birth weight, low Apgar score, and infant and maternal morbidity and mortality rates. Results: We obtained data for 80,205 women who underwent non-obstetric surgery and data for 16,655,486 women who did not undergo surgery during pregnancy. Prevalence of non-obstetric surgery was between 0.23% and 0.74% (median 0.37%). Appendectomy was the most common procedure with median prevalence of 0.10%. Near half (43%) of the procedures were performed during the second trimester, 32% during the first trimester, and 25% during the third trimester. Half of surgeries were scheduled, and half were emergent. Laparoscopic and open techniques were used equally for abdominal cavity. Women who underwent non-obstetric surgery during pregnancy had increased rate of stillbirth (odds ratio (OR) 2.0) and preterm birth (OR 2.1) compared to women without surgery. Surgery during pregnancy did not increase rate of miscarriage (OR 1.1), low 5 min Apgar scores (OR 1.1), the fetus being small for gestational age (OR 1.1) or congenital anomalies (OR 1.0). Conclusions: The prevalence of non-obstetric surgery has decreased during last decades, but still two out of 1000 pregnant women have scheduled surgery during pregnancy. Surgery during pregnancy increases the risk of stillbirth, and preterm birth. For abdominal cavity surgery, both laparoscopic and open approaches are feasible.