Are women having a vaginal birth after a previous caesarean delivery at increased risk of anal sphincter injury?

作者：Hehir M P; Fitzpatrick M; Cassidy M; Murphy M; O' Herlihy C^*

来源：BJOG: An International Journal of Obstetrics and Gynaecology , 2014, 121(12): 1515-1520.

DOI：10.1111/1471-0528.12706

• Anal sphincter injury
• morbidity
• secundiparous
• trial of labour after caesarean delivery
• vaginal birth after previous caesarean delivery

ObjectiveTo examine the incidence of obstetric anal sphincter injury in women who had a successful vaginal birth after a previous caesarean delivery (VBAC). %26lt;br%26gt;DesignRetrospective analysis of prospectively gathered data. %26lt;br%26gt;SettingA tertiary referral university institution. %26lt;br%26gt;PopulationAll secundiparous women with a previous caesarean delivery who had a VBAC from 2001 to 2011. %26lt;br%26gt;MethodsDetails of maternal demographics, intrapartum characteristics and outcomes were examined in cases of VBAC with accompanying anal sphincter injury. %26lt;br%26gt;Main outcome measuresRates of obstetric anal sphincter injury and associated risk factors. %26lt;br%26gt;ResultsDuring 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% [1216/34496], P=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 (P=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. %26lt;br%26gt;ConclusionThe 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.

• 出版日期2014-11