Risk factors of recurrent anal sphincter ruptures: a population‐based cohort study

Abstract

Objective To determine the incidence and risk factors of recurrent anal sphincter rupture (ASR).Design Population-based retrospective cohort study.Setting Data were taken from the National Medical Birth Registry, Denmark.Population Patients with a first and a second vaginal delivery in the time period 1997-2010.Methods Univariate analysis and multivariate logistic regression were used to determine risk factors of recurrent ASR.Main outcome measures The incidence of recurrent ASR and odds ratios for possible risk factors of recurrent ASR: age, body mass index, grade of ASR, birthweight, head circumference, gestational age, presentation, induction of labour, oxytocin augmentation, epidural, episiotomy, vacuum extraction, forceps, shoulder dystocia, delivery interval and year of second delivery.Results Out of 159 446 women, 7336 (4.6%) experienced an ASR at first delivery, and 521 (7.1%) had a recurrent ASR (OR 5.91). The risk factors of recurrent ASR in the multivariate analysis were: birthweight (adjusted OR, aOR, 2.94 per increasing kg, 95% CI 2.31-3.75); vacuum extraction (aOR 2.96, 95% CI 2.03-4.31); shoulder dystocia (aOR 1.98, 95% CI 1.11-3.54); delivery interval (aOR 1.08 by year, 95% CI 1.02-1.15); year of second delivery (aOR 1.06, 95% CI 1.03-1.09); and prior fourth-degree ASR (aOR 1.72, 95% CI 1.28-2.29). Head circumference was a protective factor (aOR 0.91 per increasing cm, 95% CI 0.85-0.98).Conclusions The incidence of recurrent ASR was 7.1%. Risk factors of recurrent ASR were excessive birthweight, vacuum extraction, shoulder dystocia, delivery interval, year of second delivery and prior fourth-degree ASR. A larger head circumference reduced the risk of recurrent ASR.

Feeling old in a young body: Women’s experiences of living with severe consequences of an obstetric anal sphincter rupture: An interview study

“…This is a relevant concern given that a repeated injury is known to occur in seven of 10 women with a subsequent delivery. [6] An interesting finding in our study was that the women made a distinction between the experience of bearing a child and giving birth, being pregnant for 40 weeks was considered a positive experience while the thought of the actual birth was frightening.…”

“…Risk factors for OASR are: maternal age (> 35 years), [1,2] primiparity, [1,3,4] prolonged second stage of labor (i.e. > 2 hours), [1,5] oxytocin argumentation, instrumental delivery (both mid release vacuum extraction [VE] and outlet VE), [1] VE without episiotomy, [6] and birth weight > 4,000 grams. [1,5] The risk of an OASR with a subsequent birth is 7.1%.…”

“…[1,5] The risk of an OASR with a subsequent birth is 7.1%. [6] The incidence of OASR has increased internationally during the last decennium and ranges from 0.5%-10%. [6] Percentages in Finland, Denmark, Norway and Sweden are 0.6%, 4.1%, 4.03% and 4.2%, respectively.…”

“…[6] The incidence of OASR has increased internationally during the last decennium and ranges from 0.5%-10%. [6] Percentages in Finland, Denmark, Norway and Sweden are 0.6%, 4.1%, 4.03% and 4.2%, respectively. [7] Research suggests that some of the reported increased incidence may be explained by improved diagnosis.…”

The long-term physical, emotional and psychosexual outcomes related to anal incontinence after severe perineal trauma at childbirth

“…In women who suffered OASIS at first birth, the incidence of a repeat OASIS has been shown to be 8.4% in hospital-based studies 2 and 7.2% in population-based studies 3 in the United Kingdom. In other countries, the rate of repeat OASIS in hospital-based and population-based studies has been reported to range widely from 2.0 to 7.2% 4,5 and from 5.6 to 7.1% 6,7 , respectively. Even though there are well defined risk factors for the occurrence of OASIS, such as nulliparity and instrument assistance at birth, the combination of these risk factors in different scoring systems does not allow the accurate prediction of OASIS 8 .…”