title: Non-obstetric surgery during gestation: risk factors for lower birthweight.
abstract: OBJECTIVE
  To assess the risk for preterm birth and low birthweight for women undergoing non-obstetric surgery during gestation.
  
  
  METHODS
  Two perinatal tertiary care centres.
  
  
  METHODS
  Women undergoing non-obstetric surgery during gestation between January 1989 and June 1999.
  
  
  METHODS
  A chart review was carried out. Cervical cerclages, procedures carried out under local anaesthesia or intravenous sedation, or carried out in combination with Caesarean delivery were excluded.
  
  
  METHODS
  Preterm birth (<37 weeks), birthweight.
  
  
  RESULTS
  A total of 116 of 69 800 women (0.2%) underwent non-obstetric surgery, with 96 women delivering under our care. Procedures were more commonly carried out in the second trimester (53%), versus the first (23%) or third trimester (24%). Surgery in the second trimester resulted in the lowest rate of preterm birth (11%). The overall preterm birth rate was 21% (20/96), with 13 out of 20 (65%) occurring between 35 and 37 weeks. The mean interval from surgery to delivery was 18.7 weeks. Rates of preterm birth were similar for either intra- versus extra-abdominal procedures, or general versus regional anaesthetic. Use of a general anaesthetic was associated with a significant decrease in birthweight (3053 vs 3515 g, P = 0.01) despite similar gestational ages at delivery (37.6 vs 38.6 weeks, P = 0.08). Multiple linear regression controlled for gestational age showed that general anaesthesia, longer surgery duration, and intra-abdominal procedures were all significant independent risk factors for lower birthweight.
  
  
  CONCLUSIONS
  While non-obstetric surgery appears to be relatively safe during gestation, general anaesthesia, longer surgery time, and intra-abdominal procedures are associated with lower birthweights.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Wisconsin-Madison, Meriter Hospital, Madison, WI 53715, USA. tjenkins@wisc.edu
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Jenkins
authors.forename: Suzanne F
authors.initials: SF
authors.lastname: Mackey
authors.forename: Elisa M
authors.initials: EM
authors.lastname: Benzoni
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Tolosa
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Sciscione
mesh_terms: D000768:Anesthesia, General; D001724:Birth Weight; D005260:Female; D006801:Humans; D016014:Linear Models; D007752:Obstetric Labor, Premature / Q000453:epidemiology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D012307:Risk Factors; D013514:Surgical Procedures, Operative; D013997:Time Factors