Are women having a vaginal birth after a previous caesarean delivery at increased risk of anal sphincter injury?. (13th March 2014)

• Record Type: Journal Article
• Authors: Hehir, MP; Fitzpatrick, M; Cassidy, M; Murphy, M; O'Herlihy, C
• Is Part Of: BJOG. Volume 121:Number 12(2014:Dec.)
• Page Start: 1515
• Page End: 1520
• Publication Date: 2014-03-13
• Subjects: Obstetrics -- Periodicals; Gynecology -- Periodicals; 618
• DOI: 10.1111/1471-0528.12706
• Languages: English
• ISSNs: 1470-0328

Abstract

<abstract abstract-type="main" id="bjo12706-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="bjo12706-sec-0001" sec-type="section"> <title>Objective</title> <p>To examine the incidence of obstetric anal sphincter injury in women who had a successful vaginal birth after a previous caesarean delivery (VBAC).</p> </sec> <sec id="bjo12706-sec-0002" sec-type="section"> <title>Design</title> <p>Retrospective analysis of prospectively gathered data.</p> </sec> <sec id="bjo12706-sec-0003" sec-type="section"> <title>Setting</title> <p>A tertiary referral university institution.</p> </sec> <sec id="bjo12706-sec-0004" sec-type="section"> <title>Population</title> <p>All secundiparous women with a previous caesarean delivery who had a VBAC from 2001 to 2011.</p> </sec> <sec id="bjo12706-sec-0005" sec-type="section"> <title>Methods</title> <p>Details of maternal demographics, intrapartum characteristics and outcomes were examined in cases of VBAC with accompanying anal sphincter injury.</p> </sec> <sec id="bjo12706-sec-0006" sec-type="section"> <title>Main outcome measures</title> <p>Rates of obstetric anal sphincter injury and associated risk factors.</p> </sec> <sec id="bjo12706-sec-0007" sec-type="section"> <title>Results</title> <p>During the study period there were 3071 trials of labour in secundiparous women with a previous caesarean delivery; 65% (1981/3071) of these had a successful VBAC. Women having a VBAC were at greater risk of anal sphincter injury than nulliparous women having a vaginal delivery over the same period (5% [98/1981] versus 3.5% [1216/34 496], <italic>P </italic>= 0.001, odds ratio 1.4, 95% CI 1.15–1.75). The rate of instrumental delivery in woman having a VBAC was 39% (771/1981). On multiple logistic regression analysis an increased rate of instrumental delivery was a strong predictor of sphincter injury (<italic>P</italic> = 0.03, odds ratio 1.15, 95% CI 1.01–1.3). When the first labours of women with sphincter injury in the VBAC group were examined, 70% (60/86) had been in labour before undergoing their caesarean delivery.</p> </sec> <sec id="bjo12706-sec-0008" sec-type="section"> <title>Conclusion</title> <p>The incidence of anal sphincter injury in women undergoing VBAC is 5% and birthweight is the strongest predictor of this. The rate of instrumental delivery in this group was also increased.</p> </sec> </abstract>