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Predicting perineal trauma during childbirth using data from a general obstetric population
Gillian M Maher1,2, Laura J O'Byrne1,3,4, Joye McKernan4
1INFANT Research Centre, University College Cork, Cork, T12YE02, Ireland.
Insights
A new risk prediction model identifies key factors for severe perineal tears during childbirth. Nulliparity, forceps/ventouse delivery, and higher birthweight are significant predictors, aiding in individualized risk assessment.
Area of Science:
- Obstetrics and Gynecology
- Maternal-Fetal Medicine
- Epidemiology
Background:
- Perineal trauma is a frequent childbirth complication with potential long-term health consequences.
- Limited research has investigated the combined impact of multiple risk factors on severe perineal tears.
- This study aimed to develop and validate a predictive model for third and fourth-degree perineal tears in a general obstetric population.
Purpose of the Study:
- To develop and internally validate a risk prediction model for third and fourth-degree perineal tears.
- To identify key predictors associated with severe perineal trauma during vaginal deliveries.
- To create a tool for individualized risk assessment and counseling.
Main Methods:
- A risk prediction model was developed using data from singleton vaginal deliveries (2019-2020).
- Third/fourth-degree tears were defined as involving the anal sphincter complex.
- Multivariable logistic regression and receiver operating characteristic (ROC) curve C-statistic were employed for model development and validation.
Main Results:
- The final model included nulliparity, mode of delivery (forceps/ventouse), and increasing birthweight (per 100g increase).
- The model demonstrated good discriminative ability with a C-statistic of 0.75 (95% CI: 0.71, 0.79).
- A nomogram was developed for calculating individualized risk, with good internal performance indicated by bootstrapping.
Conclusions:
- The developed nomogram provides an individualized risk assessment for third and fourth-degree perineal tears.
- This tool can assist in counseling women regarding their potential risk of severe perineal trauma.
- Further application of this model may improve patient care and informed decision-making during childbirth.
Background:
Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population.
Methods:
Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation.
Results:
Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance.
Conclusions:
Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.
