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

March 11, 2026 updated by: Stefano Salvatore, IRCCS San Raffaele

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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

110

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Primigravid admitted to labour ward for vaginal delivery
Diagnostic test: Primiparous women who have completed vaginal delivery will be submitted to a digital rectal examination and an examination with machine learning-assisted electrical impedance spectroscopy
Primiparous women who have completed vaginal delivery will be submitted to a digital rectal examination and a rectal examination with machine learning-assisted electrical impedance spectroscopy within the first hour postpartum: the examination will be performed by a gynecologist or a midwife. If an obstetric anal sphincter injury (OASI) is considered as detected women will be managed in line with local practice for OASI. In case primary surgical repair is decided, it should be carried out within 12 hours postpartum. A follow-up visit will be performed within 12 weeks postpartum. During this visit endoanal ultrasound will be performed and anal continence evaluated using Wexner score.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The investigator will evaluate the detection rate for OASI in primiparous women who have completed vaginal delivery comparing standard digital rectal digital rectal examination and machine learning-assisted electrical impedance spectroscopy.
Time Frame: From enrollment to the follow-up visit that will be performed within 12 weeks postpartum
From enrollment to the follow-up visit that will be performed within 12 weeks postpartum

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

IRCCS San Raffaele

Investigators

  • Principal Investigator: Stefano Salvatore, IRCCS San Raffele

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

March 16, 2026

Primary Completion (Estimated)

September 16, 2027

Study Completion (Estimated)

September 16, 2027

Study Registration Dates

First Submitted

March 11, 2026

First Submitted That Met QC Criteria

March 11, 2026

First Posted (Actual)

March 16, 2026

Study Record Updates

Last Update Posted (Actual)

March 16, 2026

Last Update Submitted That Met QC Criteria

March 11, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • ON-ASY

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Sphincter (Anal); Perineal Rupture, Obstetric

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