The Effect of Ultrasound Visual Feedback on Birth Outcomes in Nulliparous Women With Levator Ani Muscle Co-activation at Term Pregnancy (CoA_2025)

The Effect of Ultrasound Visual Feedback on Birth Outcomes in Nulliparous Women With Levator Ani Muscle Co-activation at Term Pregnancy: A Randomized Controlled Trial

The study aims to evaluate the effect of ultrasound-based visual feedback training of the pelvic floor muscles in nulliparous women at term pregnancy who present co-activation of the levator ani muscle, on the duration of the second stage of labor.

This is a single-center, no-profit, randomized controlled interventional study. Compared with standard clinical practice, patients will be enrolled at term pregnancy during routine antenatal care, when a first session of ultrasound-based visual feedback training will be performed using transperineal ultrasound.

Nulliparous women at term pregnancy showing co-activation of the levator ani muscle will be recruited within the standard care pathway. Participants will be randomized into two groups:

Group 1 (intervention): patients will undergo ultrasound-based visual feedback training, including real-time visualization on the ultrasound screen and explanation of the most appropriate pushing technique.

Group 2 (control): patients will receive only verbal instruction regarding the appropriate pushing technique.

Given the absence of known major confounding factors, simple randomization will be used. The randomization list will be generated electronically using the REDCap platform.

Recruitment will take place in the outpatient clinics of the Obstetrics and Prenatal Medicine Unit (U.O.C) at IRCCS AOU di Bologna, Sant'Orsola Hospital. Women in the intervention group will receive two ultrasound training sessions (visual feedback) one week apart at term pregnancy. Women in the control group, after enrollment, will be informed about the phenomenon of levator ani co-activation and will receive verbal instructions on how to relax the pelvic floor muscles.

After delivery, maternal and neonatal outcomes will be assessed, including mode of delivery, indication for operative vaginal delivery if applicable, duration of the second stage of labor, vaginal-perineal lacerations, other puerperal complications, neonatal arterial and venous pH, base excess (BE), birth weight, and neonatal intensive care unit (NICU) admission. Data will be collected through review of medical records at 40 days postpartum.

Study Overview

• Status: Recruiting
• Conditions: Pregnancy
• Intervention / Treatment: Diagnostic test: Ultrasound Visual Feedback Training

• Study Type: Interventional
• Enrollment (Estimated): 204
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Elena Brunelli, MD; Phone Number: 0512144377; Email: elena_brunelli@aosp.bo.it

Study Locations

• Italy
  • Bologna
    • Bologna, Bologna, Italy, 40138
      • Recruiting
      • IRCCS Azienda Ospedaliero-Universitaria di Bologna
      • Contact: Elena Brunelli, MD; Phone Number: 0512144377; Email: elena_brunelli@aosp.bo.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Nulliparous (first pregnancy)
• Adults (≥18 years old)
• Singleton pregnancy
• Presence of levator ani muscle co-activation at term pregnancy (37 weeks)
• Candidates for vaginal delivery
• Written informed consent signed for study participation

Exclusion Criteria:

• Presence of uterine malformations
• Presence of fetal malformations
• Presence of vaginal bleeding at the time of enrollment
• Regular uterine contractions
• Premature rupture of membranes

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ultrasound Visual Feedback Training; Participants receive ultrasound-based visual feedback training of the pelvic floor muscles using transperineal ultrasound. The intervention includes real-time visualization of pelvic floor muscle activity on the ultrasound screen, combined with structured instruction on optimal pushing techniques. Training is performed in two antenatal sessions at term pregnancy, one week apart.	Diagnostic test: Ultrasound Visual Feedback Training; Participants receive ultrasound-based visual feedback training of the pelvic floor muscles using transperineal ultrasound. The intervention includes real-time visualization of pelvic floor muscle activity on the ultrasound screen, combined with structured instruction on optimal pushing techniques. Training is performed in two antenatal sessions at term pregnancy, one week apart.
No Intervention: Verbal Instruction (Standard Care); Participants receive standard care consisting of verbal instruction regarding appropriate pushing techniques during labor and guidance on relaxation of the pelvic floor muscles in the presence of levator ani co-activation. No ultrasound visual feedback is provided.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the effect of ultrasound-based visual feedback training of the pelvic floor muscles in nulliparous women at term pregnancy presenting co-activation of the levator ani muscle, on the duration of the second stage of labor.	Assessed at delivery; calculated as the duration (minutes) from complete cervical dilation to fetal delivery.	Measured during the second stage of labor (from full cervical dilation to fetal delivery)

Collaborators and Investigators

• Sponsor: IRCCS Azienda Ospedaliero-Universitaria di Bologna

Study record dates

Study Major Dates

• Study Start (Actual): April 22, 2026
• Primary Completion (Estimated): May 13, 2031
• Study Completion (Estimated): July 1, 2031

Study Registration Dates

• First Submitted: April 15, 2026
• First Submitted That Met QC Criteria: June 26, 2026
• First Posted (Actual): June 30, 2026

Study Record Updates

• Last Update Posted (Actual): June 30, 2026
• Last Update Submitted That Met QC Criteria: June 26, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: CoA_2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No