You could be reading the full-text of this article now if you...

If you have access to this article through your institution,
you can view this article in

Subsequent Pregnancy Outcomes After Obstetric Anal Sphincter Injuries (OASIS)

Basham, Elizabeth; Stock, Laura; Lewicky-Gaupp, Christina; Mitchell, Christopher; Gossett, Dana R.

Obstetrical & Gynecological Survey:
doi: 10.1097/OGX.0000000000000031
Gynecology: Urogynecology
Abstract

ABSTRACT: The rate of obstetric anal sphincter injuries (OASISs) at the time of vaginal delivery ranges from 0.0% to 23.9%. There is increasing evidence that OASIS can be prevented during birth by decreased use of 2 established risk factors for OASIS, use of episiotomies, and the use of forceps during operative vaginal deliveries. Few studies have investigated risk factors for recurrence of OASIS in a subsequent pregnancy.

The aim of this retrospective study was to determine the rate of recurrent OASIS in women with a prior OASIS and to identify risk factors for recurrence. Participants were women who sustained an OASIS between November 2005 and March 2010 at a tertiary care hospital; data were obtained by review of their charts.

A total of 1629 women had an OASIS, and 758 (46%) went on to have a subsequent pregnancy during the study period; 685 (90%) were delivered vaginally. Twenty-three (3.2%) of these women sustained a recurrent sphincter injury. Risk factors for recurrence included larger birth weight (27% ≥4000 g vs 11.6% <4000 g; P = 0.04) and delivery mode (25.0%, 12.5%, and 2.7% for forceps-assisted, vacuum-assisted, and spontaneous deliveries, respectively; P = 0.0001). Neither a history of a fourth-degree laceration, prior wound complications, or episiotomy at a subsequent delivery increased the risk of recurrence.

These data show that the observed rate of recurrent OASIS was only 3.2% among women who subsequently delivered vaginally. Significant risk factors for recurrence were operative vaginal delivery and birth weight 4000 g or greater. Neither episiotomy at first delivery or at subsequent delivery increased recurrence risk.

Author Information

Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL

© 2014 by Lippincott Williams & Wilkins.