Levator ani injury in primiparous women with forceps delivery for fetal distress, forceps for second stage arrest, and spontaneous delivery

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). Conclusion: 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. (C) 2010 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.