title: Levator ani injury in primiparous women with forceps delivery for fetal distress, forceps for second stage arrest, and spontaneous delivery.
abstract: OBJECTIVE
  To compare levator ani muscle injury rates in primiparous women who had a forceps delivery owing to fetal distress with women delivered by forceps for second stage arrest; and to compare these injury rates with a historical control group of women who delivered spontaneously.
  
  
  METHODS
  Primiparous women who delivered by forceps were recruited retrospectively into 2 groups: forceps for fetal distress with short second stage (25±11 minutes; n=19); and forceps delivery for second stage arrest (137±26 minutes; n=19). MR images of the levator ani muscles were compared with a historical control group of women from a previous study who had delivered spontaneously (n=129).
  
  
  RESULTS
  Major defect rates were: 42% for forceps and short second stage; 63% for forceps and second stage arrest; and 6% for spontaneous delivery. The odds ratios for major injury were: 11.0 for forceps and short second stage compared with spontaneous delivery; 25.9 for forceps and second stage arrest compared with spontaneous delivery; and 2.3 for forceps and second stage arrest compared with short second stage (P=0.07).
  
  
  CONCLUSIONS
  Women delivered by forceps have a higher rate of levator ani injury compared with spontaneous delivery controls; the difference between the forceps groups did not reach significance.
authors.affiliation: Department of Obstetrics and Gynecology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, UK. rkearney@doctors.net.uk
authors.forename: Rohna
authors.initials: R
authors.lastname: Kearney
authors.forename: Myra
authors.initials: M
authors.lastname: Fitzpatrick
authors.forename: Sandra
authors.initials: S
authors.lastname: Brennan
authors.forename: Michael
authors.initials: M
authors.lastname: Behan
authors.forename: Janis
authors.initials: J
authors.lastname: Miller
authors.forename: Declan
authors.initials: D
authors.lastname: Keane
authors.forename: Colm
authors.initials: C
authors.lastname: O'Herlihy
authors.forename: John O L
authors.initials: JO
authors.lastname: DeLancey
mesh_terms: D036861:Delivery, Obstetric; D005260:Female; D005316:Fetal Distress / Q000601:surgery*; D006801:Humans; D007748:Labor Stage, Second; D018482:Muscle, Skeletal / Q000293:injuries*; D009772:Obstetrical Forceps / Q000009:adverse effects*; D036801:Parturition; D017773:Pelvic Floor / Q000293:injuries / Q000601:surgery; D011247:Pregnancy; D012189:Retrospective Studies