title: Effect of Pregnancy on Adverse Outcomes After General Surgery.
abstract: OBJECTIVE
  The literature regarding the occurrence of adverse outcomes following nonobstetric surgery in pregnant compared with nonpregnant women has conflicting findings. Those differing conclusions may be the result of inadequate adjustment for differences between pregnant and nonpregnant women. It remains unclear whether pregnancy is a risk factor for postoperative morbidity and mortality of the woman after general surgery.
  
  
  OBJECTIVE
  To compare the risk of postoperative complications in pregnant vs nonpregnant women undergoing similar general surgical procedures.
  
  
  METHODS
  In this retrospective cohort study, data were obtained from the American College of Surgeons' National Surgical Quality Improvement Program participant user file from January 1, 2006, to December 31, 2011. Propensity-matched females based on 63 preoperative characteristics were matched 1:1 with nonpregnant women undergoing the same operations by general surgeons. Operations performed between January 1, 2006, and December 31, 2011, were analyzed for postoperative adverse events occurring within 30 days of surgery.
  
  
  METHODS
  Rates of 30-day postoperative mortality, overall morbidity, and 21 individual postoperative complications were compared.
  
  
  RESULTS
  The unmatched cohorts included 2764 pregnant women (50.5% underwent emergency surgery) and 516,705 nonpregnant women (13.2% underwent emergency surgery) undergoing general surgery. After propensity matching, there were no meaningful differences in all 63 preoperative characteristics between 2539 pregnant and 2539 nonpregnant patients (all standardized differences, <0.1). The 30-day mortality rates were similar (0.4% in pregnant women vs 0.3% in nonpregnant women; P = .82), and the rate of overall morbidity was also not significantly different between pregnant vs nonpregnant patients (6.6% vs 7.4%; P = .30).
  
  
  CONCLUSIONS
  There was no significant difference in overall morbidity or 30-day mortality rates in pregnant and nonpregnant propensity-matched women undergoing similar general surgical operations. General surgery appears to be as safe for pregnant women as it is for nonpregnant women.
authors.affiliation: Department of Surgery, School of Medicine, University of Colorado, Aurora.
authors.forename: Hunter B
authors.initials: HB
authors.lastname: Moore
authors.affiliation: Surgical Outcomes and Applied Research Program, School of Medicine, University of Colorado, Aurora3Adult and Child Center for Health Outcomes Research and Delivery Science, School of Medicine, University of Colorado, Aurora4Department of Biostatistics and.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Juarez-Colunga
authors.affiliation: Surgical Outcomes and Applied Research Program, School of Medicine, University of Colorado, Aurora3Adult and Child Center for Health Outcomes Research and Delivery Science, School of Medicine, University of Colorado, Aurora.
authors.forename: Michael
authors.initials: M
authors.lastname: Bronsert
authors.affiliation: Surgical Outcomes and Applied Research Program, School of Medicine, University of Colorado, Aurora3Adult and Child Center for Health Outcomes Research and Delivery Science, School of Medicine, University of Colorado, Aurora5Division of Cardiology, Departm.
authors.forename: Karl E
authors.initials: KE
authors.lastname: Hammermeister
authors.affiliation: Surgical Outcomes and Applied Research Program, School of Medicine, University of Colorado, Aurora3Adult and Child Center for Health Outcomes Research and Delivery Science, School of Medicine, University of Colorado, Aurora4Department of Biostatistics and.
authors.forename: William G
authors.initials: WG
authors.lastname: Henderson
authors.affiliation: Department of Surgery, School of Medicine, University of Colorado, Aurora6Department of Surgery, Denver Health Medical Center, Denver, Colorado.
authors.forename: Ernest E
authors.initials: EE
authors.lastname: Moore
authors.affiliation: Department of Surgery, School of Medicine, University of Colorado, Aurora2Surgical Outcomes and Applied Research Program, School of Medicine, University of Colorado, Aurora.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Meguid
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D009017:Morbidity / Q000639:trends; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D058996:Quality Improvement; D012189:Retrospective Studies; D012307:Risk Factors; D013514:Surgical Procedures, Operative; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology