Pelvic Floor Ultrasound Before Induction of Labour and Labour Outcome

NCT07797387 | Not Yet Recruiting

• 1 other identifier: LEVATOR-IOL-2026-01
• Study Type: observational
• Target: 140
• Locations: 1 country
• Sites: 1

Brief Summary

Pregnancy and vaginal birth are the main causes of pelvic floor disorders such as urinary incontinence and pelvic organ prolapse. The levator hiatus - the opening in the pelvic floor muscles through which the baby passes - can be measured on three-dimensional transperineal ultrasound at rest, during pelvic floor contraction and during a Valsalva manoeuvre. Its size and its ability to stretch have been related to how long labour lasts and to how the baby is eventually born, but the evidence comes mostly from women in spontaneous labour, in whom the exact time labour began cannot be established. Women having their labour induced offer a better model, because the time each stage of labour begins is documented. Recently, automated software has made the measurement of the levator hiatus fast and reproducible, which makes it realistic to use in everyday practice. This prospective observational study will enrol 140 women with a singleton pregnancy at 36 weeks or more who are scheduled for induction of labour. Before induction begins, each woman will have a transperineal ultrasound scan of the pelvic floor at rest, on maximum contraction and on maximum Valsalva. The scan does not involve any vaginal probe, radiation or injection, and takes about 15 minutes. The times of each phase of labour, the way the baby is born and the condition of the perineum after birth will be recorded prospectively from the clinical record. The scan will be repeated before hospital discharge and about one month after birth, together with validated pelvic floor symptom questionnaires. The main question is whether the area of the levator hiatus measured on Valsalva before induction is related to the duration of the active, pushing phase of the second stage of labour. The study will also examine the duration of the first stage, the mode of delivery, and how the pelvic floor changes in the first month after an induced birth. Study procedures do not influence clinical care in any way: induction and labour are managed according to standard departmental protocols, and the research ultrasound results are not disclosed to the clinical team.

Conditions

Labor; Pelvic Floor Disorder; Labor Stage, Second; Induced Labor; Pelvic Floor; Levator Ani Muscle Injury

Keywords

transperineal ultrasound; levator hiatus; pelvic floor; induction of labor; second stage of labor; 3d Ultrasound; levator ani; automated segmentation

Outcome Measures

Primary Outcomes (1)

• Duration of the active (pushing) second stage of labour

  Time elapsed from the onset of active maternal pushing to delivery of the fetus, recorded in minutes from the clinical record, analysed in relation to the levator hiatal area measured on maximum Valsalva before induction

  From the onset of active pushing to delivery, assessed up to 4 hours

Secondary Outcomes (10)

• Duration of the active phase of the first stage of labour

  From the onset of the active phase to full dilatation, assessed up to 24 hours.

• Duration of the passive second stage of labour

  From full dilatation to the onset of pushing, assessed up to 4 hours.

• Induction-to-delivery interval

  From the start of induction to delivery, assessed up to 96 hours.

• Mode of delivery a

  at delivery

• Change in levator hiatal area on Valsalva from before induction to hospital discharge

  Before induction (36 weeks of gestation or later) and 24 to 96 hours after delivery

Other Outcomes (1)

• Intra- and interobserver reproducibility of automated levator hiatal area measurement

  Before induction, with manual analysis performed at least 2 weeks after automated analysis.

Study Arms (1)

Women undergoing induction of labour

Women with a singleton cephalic pregnancy at 36 weeks of gestation or more, admitted for induction of labour with the intention of vaginal birth, assessed by three-dimensional transperineal pelvic floor ultrasound before induction, before hospital discharge and one month after delivery.

Diagnostic Test: Three-dimensional transperineal pelvic floor ultrasound

Interventions

Three-dimensional transperineal pelvic floor ultrasound DIAGNOSTIC_TEST

Transperineal acquisition of 3D/4D pelvic floor volumes at rest, on maximum pelvic floor contraction and on maximum Valsalva manoeuvre, using a transabdominal volumetric probe applied translabially with the woman in the lithotomy position and an empty bladder. Levator hiatal area and diameters are measured offline on the plane of minimal hiatal dimensions using automated segmentation software, with manual tracing as a quality control. No vaginal or rectal probe is used and no ionising radiation is involved. - Other names: TPUS; pelvic floor ultrasound

Women undergoing induction of labour

Eligibility Criteria

• Age: 18 Years+
• Gender Eligibility Details: The study concerns pregnancy, labour and the female pelvic floor
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Consecutive women with a singleton cephalic pregnancy at 36 weeks of gestation or more admitted to the induction of labour service of a tertiary maternity unit, with the intention of vaginal birth, who consent to research pelvic floor ultrasound before the start of cervical ripening.

You may qualify if:

• Age 18 years or older
• Singleton pregnancy with cephalic presentation
• Gestational age of 36 weeks 0 days or more, dated by first-trimester crown-rump length
• Scheduled for induction of labour with a planned attempt at vaginal delivery, for any clinical indication
• Ultrasound assessment feasible before administration of the first cervical ripening agent

You may not qualify if:

• Known fetal structural or chromosomal anomaly
• Previous caesarean section or previous uterine surgery
• Planned caesarean section or a contraindication to vaginal delivery arising before the ultrasound assessment
• Connective tissue disease, neuropathy or neuromuscular disease affecting the pelvic floor
• Previous pelvic floor or anti-incontinence surgery - Active labour, or ruptured membranes with regular contractions, at the time of the scheduled assessment
• Inability to perform an adequate Valsalva manoeuvre or pelvic floor contraction after standardised instruction
• Inability to provide informed consent or to understand the study questionnaires

Sponsors & Collaborators

• University of Roma La Sapienza: lead

Study Sites (1)

Azienda Ospedaliero-Universitaria Policlinico Umberto I, Department of Maternal and Child Health and Urological Sciences

Roma, RM, 00161, Italy

Location

Related Publications (5)

• Dietz HP, Shek C, Clarke B. Biometry of the pubovisceral muscle and levator hiatus by three-dimensional pelvic floor ultrasound. Ultrasound Obstet Gynecol. 2005 Jun;25(6):580-5. doi: 10.1002/uog.1899.

  PMID: 15883982 RESULT

• Ishii K, Futaki S, Uchiyama H, Nagasawa K, Andoh T. Mechanism of inhibition of mammalian DNA topoisomerase I by heparin. Biochem J. 1987 Jan 1;241(1):111-9. doi: 10.1042/bj2410111.

  PMID: 3032152 RESULT

• Brunelli E, Del Prete B, Casadio P, Pilu G, Youssef A. The dynamic change of the anteroposterior diameter of the levator hiatus under Valsalva maneuver at term and labor outcome. Neurourol Urodyn. 2020 Nov;39(8):2353-2360. doi: 10.1002/nau.24494. Epub 2020 Aug 31.

  PMID: 32865824 RESULT

• Youssef A, Brunelli E, Pilu G, Dietz HP. The maternal pelvic floor and labor outcome. Am J Obstet Gynecol MFM. 2021 Nov;3(6S):100452. doi: 10.1016/j.ajogmf.2021.100452. Epub 2021 Aug 6.

  PMID: 34365028 RESULT

• Resta S, De Vito M, Patelli C, Lu JLA, Gabrielli G, Chiodo E, Mappa I, Rizzo G. Validation of an automated software (Smartpelvic) in assessing hiatal area from three dimensional transperineal pelvic volumes of pregnant women: comparison with manual analysis. J Perinat Med. 2023 Nov 9;52(2):165-170. doi: 10.1515/jpm-2023-0323. Print 2024 Feb 26.

  PMID: 37938105 RESULT

MeSH Terms

Conditions

Pelvic Floor Disorders; Neoplasm Metastasis

Condition Hierarchy (Ancestors)

Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Pregnancy Complications; Male Urogenital Diseases; Neoplastic Processes; Neoplasms; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Giuseppe Rizzo

  Università Roma Sapienza

  STUDY DIRECTOR

Central Study Contacts

Giuseppe Rizzo, Prof

CONTACT

+39 06 49971; giuseppe.rizzo@uniroma1.it

Ilenia Mappa, Prof

CONTACT

39+06 49971; giuseppe.rizzo@uniroma2.it

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof

Study Record Dates

• First Submitted: August 27, 2026
• First Posted: September 1, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): November 1, 2028
• Last Updated: September 3, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Beginning 12 months and ending 5 years after publication of the primary results
• Access Criteria: Requests should be directed to the principal investigator and will require a signed data access agreement and evidence of ethics approval for the proposed secondary analysis.

Locations

IT (1)