Crowning time and levator ani muscle detachment after a first vaginal birth

Evaluation of Crowning Time on the Incidence of Levator Ani Muscle Avulsion

Observational Université de Sherbrooke · NCT07210788

We will see if the length of time the baby's head is crowning during labor is linked to levator ani muscle detachment in first-time moms who have a spontaneous vaginal birth.

Quick facts

Study typeObservational
Enrollment92 (estimated)
Ages18 Years and up
SexFemale
SponsorUniversité de Sherbrooke Academic / other
Locations1 site (Sherbrooke, Quebec)
Trial IDNCT07210788 on ClinicalTrials.gov

What this trial studies

This prospective cohort study follows primiparous women with a term, cephalic, spontaneous vaginal delivery to test whether crowning time in the second stage of labor is associated with levator ani muscle avulsion. Crowning time is routinely recorded by clinical staff during labor and participants will receive a standardized 4D transperineal ultrasound in the postpartum period to detect avulsion. Delivery records will be reviewed to collect potential confounders such as episiotomy and other delivery interventions. Enrollment is restricted to singleton, unassisted vaginal births to reduce confounding and focus on the specific effect of crowning time.

Who should consider this trial

Good fit: Adult first-time (primiparous) women at term (≥37 weeks) with a spontaneous, cephalic vaginal delivery are the intended participants.

Not a fit: Women who have cesarean deliveries, assisted vaginal births (forceps/vacuum), multifetal pregnancies, prior extensive pelvic surgery, or other exclusion criteria are unlikely to be included or to benefit directly from the findings.

Why it matters

Potential benefit: If a link is found, clinicians could change labor management or episiotomy decisions to reduce pelvic floor injuries and lower future risks of incontinence and prolapse.

How similar studies have performed: Ultrasound detection of levator ani avulsion and links to instrumented delivery are established, but using recorded crowning time as a predictor is a novel question with little prior data.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Primiparous women GxT1 At term: ≥ 37+0 weeks of gestation (included) Spontaneous vaginal delivery (SVD) Cephalic presentation History of miscarriage before 20 weeks or with a fetal weight \< 350g

Exclusion Criteria:

Contraindications to vaginal delivery Assisted vaginal delivery Age under 18 years Shoulder dystocia Extensive pelvic reconstructive surgery (e.g., bladder exstrophy repair) Term intrauterine fetal demise Twin or multifetal pregnancy

Where this trial is running

Sherbrooke, Quebec

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Time of the Crowning of the Fetal HeadLevator Ani AvulsionLabor DeliveryPostpartumlevator anilevator ani avulsioncrowning timecrowning time of the fetal head
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.