EP19.21: The use of vaginal probe transperineal as screening tool of occult perineal tear in postpartum women

Perineal tear complicates >85% of vaginal deliveries and obstetric anal sphincter injuries (OASIS) ranges from 0.6-9%. Majority of OASIS unrecognised at delivery (occult OASIS). The diagnosis of OASIS is made based on clinical examination and imaging modalities such as magnetic resonance imaging (MRI) and ultrasonography (USG). Endoanal ultrasound is the gold standard for assessing the anal sphincter complex, but its availability is limited and its use requires a trained operator. This study aims to determine the accuracy of vaginal probe transperineal as a screening tool for anal sphincter injury in women after vaginal delivery. The study was conducted at Dr. Mohammad Hoesin (RSMH) Palembang from July 2021 to February 2022. There were 42 subjects who met the inclusion criteria. The degree of perineal tear was evaluated and perineal suture was performed after vaginal delivery. Transperineal ultrasound using vaginal probe to evaluate anal sphincter was performed at 24-72 hours after vaginal delivery. From 42 subjects, 33 subjects had perineal tears (78.6%). Based on ultrasound examination, there were 9 (21.4%) subjects with OASIS where 8 of them were not detected on clinical examination. The risk factors for OASIS in this study were nullipara (p = 0.042) and mode of delivery (p = 0.016). Ultrasound examination using vaginal probe transperineal had a sensitivity of 100%, specificity of 80.5%, PPV of 11%, and NPV of 100%. The accuracy test between ultrasound with vaginal probe transperineal and clinical examination as a perineal tear screening is very good (80.9%). Ultrasound examination with vaginal probe transperineal can be used not only as screening tool but also as diagnostic tool for OASIS.