Anovaginal Distance Measured by Transperineal Ultrasound as a Predictor for Birth- Related perineal Trauma

Background: Birth- related perineal trauma (BPT) complicates more than 90% of vaginal deliveries and obstetric anal sphincter injuries(OASIS) are the severe degree of BPT. Transperineal Ultrasonography (TPUS) can be used to measure Anovaginal distance (AVD) which probably relates to OASIS.Aim: To determine the relation between AVD measured by TPUS and BPT.Patients and methods: Prospective Observational study included 140 Nulliparous women in the obstetric emergency department in the hospital of Suez Canal university from June 2024 to May 2025. After the approval of the ethical committee and after participants consent, nulliparous women with singleton vertex pregnancy who gave spontaneous vaginal delivery between 37 to 40 weeks of gestation were recruited. Each participant was interviewed for history, examination and ultrasound (US) assessment then observed through and after delivery. Results: Analysis revealed an extremely statistically significant association between AVD measured by TPUS and the degree of perineal tears (p<0.001).Conclusion: Short maternal AVD is considered a risk factor for BPT and OASIS.