Scoring System to Predict Levator Ani Injury in Vaginal DeliveryBudi Iman SantosoInternational Urogynecology Association (IUGA) Regional SymposiumBali, Nov 7-9 2013

BackgroundLevator ani muscle is an important structure that link vaginal delivery to pelvic floor dysfunction (PFD). Various symptoms of PFD had been established as one of the problems during womens life.1 In the middle of maternal mortality problems in Indonesia, several attempts to increase womens quality of life have been consistently developed. Research and education are developed to address the health aim among Indonesian women. It had been demonstrated that PFD carried the risk of urinary incontinence, fecal incontinence, pelvic organ prolapse and sexual dysfunction that will lead to the cost and quality of life problems. In the United States, there is a need of over 200,000 surgical procedures to correct pelvic floor dysfunction per year.2 Therefore obstetricians should be aware to the PFD prevention, particularly levator ani injury.

Prevalence of levator ani damage at 3-months after delivery is 15-30% in women with vaginal delivery.2 Obstetricians and gynecologists have assumed that the natural mode of delivery or vaginal childbirth may contribute to the levator ani damage. However, the clinical relevance of the association between levator ani damage and developing symptoms of pelvic floor dysfunction is still unclear. Many women with levator ani damage did not have symptoms of pelvic floor dysfunction.3

In last decade, the number of Caesarean birth has increased 50%, 2.5% of which were performed on mother request.4 Moreover, the concern on pelvic floor dysfunction which leads to the selection Caesarean birth seems to be over-worried, since the Caesarian birth actually could only prevent 1 of 7 women from experiencing levator ani damage due to vaginal birth. It should be noted that the mortality risk of Caesarean birth increases up to five times compared to vaginal birth. Moreover, there are various risk factors or levator ani injury, i.e. demographic and obstetric risk factors.5 Demographic risk factors include maternal age, race, parity and body mass index (BMI).6 Obstetric risk factors include age at first delivery, mode of delivery, second stage period, fetal birth weight, episiotomy, and perineum rupture.7

Until now, there have been no attempts to integrate various risk factors that can be utilized to predict levator ani injury caused by vaginal delivery. Therefore, a scoring system that could predict the occurrence of levator ani injury is required. When the scoring system suggests a low risk of levator ani injury, then the patient could be convinced to choose vaginal birth without any fear of the developing pelvic floor dysfunction. We established the scoring system by using various risk factors to predict levator ani injury in vaginal delivery.7

MethodsA prospective cohort was conducted at two hospitals in Jakarta between 2010 and 2011. The subjects were nulipara pregnant women without levator ani injury during pregnancy and vaginal birth. Levator ani injury was evaluated using 4D USG during pregnancy and three months after delivery. The variables studied were age, body mass index, mode of delivery, fetal birth weight, episiotomy, perineum rupture and duration of second stage labor. Prediction model was analyzed using logistic regression analysis.

ResultThere were 182 recruited subjects of which 124 subjects were eligible and only 104 subjects could be analyzed. Incidence of levator ani injury at three months after delivery was 15.4% (95% CI: 8.6-23%). Two prediction models were obtained. The first consisted of fetal birth weight (OR= 5.36, 95% CI: 1.08-26.59), episiotomy (OR= 5.41, 95% CI: 0.94- 31.18), and duration of second stage labor (OR= 15.27, 95% CI: 3.15-73.96). The second model consisted of duration of second stage labor (OR= 9.51, 95% CI: 1.23-68.10) and perineum rupture (OR= 142.70, 95% CI: 14.13-1440.78).

Table 1. Comparison between model 1 and model 2 of scoring system predicting levator any injuryParameterComparison between model 1 and model 2

Prognostic valuePrognostic value of model 2 is better than model 1. However, the prognostic values of both models are quite strong.

Feasibility Model 1 is feasible in all health care centers. Almost every health care personnel are able to evaluate stage 2 labor and perform episiotomy. Model 2 is feasible for health care centers where the medical personnel able to evaluate perineum rupture.

Table 2. Scoring Card-Model 1Variables Patients scoreTotal scoreConclusion

Probability of avulsion on three-month observation Risk classification

Episiotomy Score 0 Score 1 Score 2 Score 3 Score 41.04.416.746.979.5 Low risk (total score of 0-1) Moderate risk (total score of 2) High risk (total score of 3-4)

Yes (score 1)

No (score 0)

Stage 2 labor

65 minutes (score 2)