title: Incidence of incisional hernia after cesarean delivery: a register-based cohort study.
abstract: OBJECTIVE
  To estimate the incidence of incisional hernias requiring surgical repair after cesarean delivery over a 10-year period.
  
  
  METHODS
  This population- and register-based cohort study identified all women in Denmark with no history of previous abdominal surgery who had a cesarean delivery between 1991 and 2000. The cohort was followed from their first until 10 years after their last cesarean delivery within the inclusion period or until the first of the following events: hernia repair, death, emigration, abdominal surgery, or cesarean delivery after the inclusion period. For women who had a hernia repair, hospital records regarding the surgery and previous cesarean deliveries were tracked and manually analyzed to validate the relationship between hernia repair and cesarean delivery. Data were analyzed with a competing risk analysis that included each cesarean delivery.
  
  
  RESULTS
  We identified 57,564 women who had had 68,271 cesarean deliveries during the inclusion period. During follow-up, 134 of these women had a hernia requiring repair. Of these 68 (51% [95% CI 42-60%]) were in a midline incision although the transverse incision was the primary approach at cesarean delivery during the inclusion period. The cumulated incidence of a hernia repair within 10 years after a cesarean delivery was 0.197% (95% CI 0.164-0.234%). The risk of a hernia repair was higher during the first 3 years after a cesarean delivery, with an incidence after 3 years of 0.157% (95% CI 0.127-0.187%).
  
  
  CONCLUSIONS
  The overall risk of an incisional hernia requiring surgical repair within 10 years after a cesarean delivery was 2 per 1000 deliveries in a population in which the transverse incision was the primary approach at cesarean delivery.
authors.affiliation: Department of Obstetrics and Gynecology, University of Copenhagen, Holbæk Hospital, Holbæk, Denmark.
authors.forename: Anna J M
authors.initials: AJ
authors.lastname: Aabakke
authors.affiliation: Department of Obstetrics and Gynecology, University of Copenhagen, Holbæk Hospital, Holbæk, Denmark.
authors.forename: Lone
authors.initials: L
authors.lastname: Krebs
authors.affiliation: Clinical Research Center, University of Copenhagen, Hvidovre Hospital, Hvidovre, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Ladelund
authors.affiliation: The Research Unit Women's and Children's Health, The Juliane Marie Center, Copenhagen University Hospital, Copenhagen, Denmark; Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Niels J
authors.initials: NJ
authors.lastname: Secher
mesh_terms: D000328:Adult; D002585:Cesarean Section; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D046449:Hernia, Abdominal / Q000453:epidemiology* / Q000601:surgery; D059685:Herniorrhaphy; D006801:Humans; D015994:Incidence; D011183:Postoperative Complications; D011247:Pregnancy; D012042:Registries