Risk Factors and Risk Stratification for Adverse Obstetrical Outcomes After Appendectomy or Cholecystectomy During Pregnancy

IMPORTANCE Identification of risk factors for adverse obstetrical outcomes after appendectomy and cholecystectomy during pregnancy is necessary for evidence-based risk reduction and adequate patient counseling. OBJECTIVES To identify risk factors for adverse obstetrical outcomes after appendectomy and cholecystectomy during pregnancy and stratify the risk of such outcomes. DESIGN, SETTING, AND PARTICIPANTS A cohort study was conducted using the Nationwide Inpatient Sample, a nationally representative sample of patients discharged from community hospitals in the United States, from January 1, 2003, to December 31, 2012. Multivariable analysis of risk factors for adverse obstetric outcomes was performed for 19 926 women undergoing appendectomy or cholecystectomy during pregnancy and a scoring system for such risk factors was developed. Data analysis was conducted from January 1, 2015, to July 31, 2016. MAIN OUTCOMES AND MEASURES A composite measure including 7 adverse obstetrical outcomes throughout pregnancy and occurring before hospital discharge. RESULTS Of the 19 926 women (mean [SD] age, 26 [6] years) in the study, 1018 adverse obstetrical events were recorded in 953 pregnant women (4.8%). The 3 most frequent adverse events were preterm delivery (360 [35.4%]), preterm labor without preterm delivery (269 [26.4%]), and miscarriage (262 [25.7%]). The risk factors associated most strongly with an adverse obstetrical outcome included cervical incompetence (adjusted odds ratio, 24.29; 95% CI, 7.48-78.81), preterm labor during current pregnancy (adjusted odds ratio, 18.34; 95% CI, 4.95-67.96), vaginitis or vulvovaginitis (adjusted odds ratio, 5.17; 95% CI, 2.19-12.23), and sepsis (adjusted odds ratio, 3.39; 95% CI, 2.08-5.51). A scoring system based on statistically significant variables classified the study sample into 3 risk groups corresponding to predicted probabilities of adverse obstetrical outcomes of 2.5%(<= 4 points), 8.2%(5-8 points), and 21.8% (>= 9 points). CONCLUSIONS AND RELEVANCE Approximately 5% of women experience adverse obstetrical outcomes after appendectomy or cholecystectomy during pregnancy. The major risk factors for such outcomes are cervical incompetence, preterm labor during current pregnancy, vaginitis or vulvovaginitis, and sepsis.