The investigator will evaluate the detection rate for Obstetric Anal Sphincter Injuries (OASI) in primiparas having given vaginal childbirth, comparing the sensitivity of methods available in a labour ward setting for rapid detection: standard digital rectal examination (DRE) and Machine Learning-assisted electrical impedance spectroscopy (applied with the ONIRY system).
Endoanal Ultrasound (EAUS) is used as the reference standard for diagnosis' confirmation and performed within 12 weeks post-delivery.