Digital Rectal Examination vs Machine Learning-assisted Electrical Impedance Spectroscopy for Obstetric Anal Sphincter Injuries' Detection: a Prospective Cohort Study in Primiparous Women Giving Vaginal Childbirth

Digital Rectal Examination vs Machine Learning-assisted Electrical Impedance Spectroscopy for Obstetric Anal Sphincter Injuries' Detection: a Prospective Cohort Study in Primiparous Women Giving Vaginal Childbirth

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.

Inclusion Criteria:

• Adult, legally competent woman
• Freely given written informed consent
• Pregnant, primigravid, admitted to labour ward and planned for vaginal delivery
• Woman in the early postpartum period (up to 1 hour postpartum) after the vaginal (spontaneous or assisted) childbirth, of a neonate of birth weight of at least 500 g or, if birth weight does not apply, gestational age of at least 22 completed weeks; if neither of the two applies, the neonate crown-heel length of at least 25cm
• Absence of any contraindication for use of machine learning-assisted electrical impedance spectroscopy
• Not currently participating or planned for any other research study related to obstetrics or proctology

Exclusion Criteria:

• Active inflammatory bowel disease affecting the perianal area
• Implants in the pelvic area
• Major malformations in perianal area or anal prolapse