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Decision-Making in Labor Admission Using Transperineal Ultrasound vs. Vaginal Examination

Toma de Decisiones en la Admisión Hospitalaria al Parto Con Ecografía Transperineal vs. Tacto Vaginal: Estudio Aleatorizado Controlado

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07278271
Enrollment
170
Registered
2025-12-12
Start date
2024-01-29
Completion date
2026-03-31
Last updated
2025-12-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Labor Active Dilated Cm

Keywords

Transperineal ultrasound, Intrapartum ultrasound, Vaginal examination, Hospital admission in labor, Term pregnancy, Angle of progression, Cervical dilatation, Ultrasound vs vaginal exam

Brief summary

This clinical trial aims to determine whether transperineal ultrasound (a perineal external scan) can improve decision-making for hospital admission in term pregnant women in labor compared to traditional vaginal examination. Term pregnant women (\>37 weeks) presenting with contractions at the emergency department will be randomly assigned to undergo either a transperineal ultrasound or a vaginal examination upon arrival. The study will evaluate whether ultrasound-based assessment reduces the rate of labor inductions and decreases patient discomfort during the admission evaluation. All participants will receive standard clinical evaluation and follow-up according to the assigned method, report discomfort levels using a standardized scale, and have labor outcomes recorded - including induction, oxytocin use, time to delivery, and mode of delivery -, to determine whether ultrasound improves clinical decision-making and maternal comfort.

Detailed description

This single-center, prospective, randomized controlled clinical trial is designed to evaluate whether transperineal ultrasound provides a more effective and less discomforting method than standard vaginal examination for decision-making regarding hospital admission in term pregnant women presenting with contractions. Vaginal examination remains the standard approach for assessing labor progression but is known to be subjective, poorly reproducible, and frequently uncomfortable for patients. In contrast, transperineal ultrasound offers objective and reproducible parameters such as cervical dilation, fetal head station, angle of progression, and head-perineum distance. Incorporating these measurements into the clinical evaluation may optimize admission criteria, reduce unnecessary hospitalizations, and lower the rate of labor inductions. After obtaining informed consent, eligible participants will be randomly assigned in a 1:1 ratio to either a transperineal ultrasound group or a standard vaginal examination group. In the ultrasound group, hospital admission will be recommended when cervical dilation is ≥3 cm or the angle of progression exceeds 120°, in the presence of regular uterine contractions. In the vaginal examination group, admission will be recommended when cervical dilation is ≥4 cm with regular contractions. Maternal discomfort during the evaluation will be assessed on a 0-10 numerical scale, and all labor outcomes and interventions will be recorded in standardized case report forms. A total of 170 participants (85 per group) will be enrolled to detect an 18% difference in labor induction rates with 80% power and a 95% confidence level. Statistical analyses will include descriptive and comparative methods (Chi-square, t-test, or non-parametric equivalents), with significance defined as p\<0.05. The study will adhere to the principles of the Declaration of Helsinki and comply with applicable data protection regulations, including the Spanish Ley Orgánica de Protección de Datos (Organic Law on Data Protection, LOPD) and the European General Data Protection Regulation (GDPR).All participants will provide written informed consent prior to inclusion, and all data will be anonymized. The protocol has received approval from the institutional ethics committee. This trial builds upon prior observational findings demonstrating high agreement between ultrasound-based and traditional methods for assessing labor progression. By generating high-level evidence, it aims to support the implementation of transperineal ultrasound in labor triage protocols, improving the accuracy of clinical decision-making, enhancing maternal comfort, and contributing to better obstetric outcomes.

Interventions

Transperineal ultrasound will be performed to assess cervical dilatation, angle of progression, fetal head position, and head-perineum distance. Admission decisions will be made based on predefined sonographic thresholds.

DIAGNOSTIC_TESTVaginal Examination

Standard digital vaginal examination will be conducted to assess cervical dilatation. Admission decisions will follow institutional protocol (≥4 cm dilation with regular contractions).

Sponsors

Hospital Universitario La Paz
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No

Inclusion criteria

* Women aged 18 to 45 years * Singleton pregnancy * Gestational age ≥ 37 weeks (term pregnancy) * Spontaneous uterine contractions at the time of presentation to the emergency department * Cephalic presentation * Willingness and ability to provide written informed consent

Exclusion criteria

* Premature rupture of membranes (PROM) * Multiple gestation * Known high-risk pregnancy (e.g., preeclampsia, intrauterine growth restriction, insulin-dependent diabetes) * Previous cesarean delivery * Breech or other non-cephalic presentation * Elective cesarean section planned or requested * Refusal to undergo vaginal delivery * Inability or unwillingness to comply with the study protocol

Design outcomes

Primary

MeasureTime frameDescription
Rate of Labor InductionFrom hospital admission decision to deliveryProportion of participants who undergo labor induction if admitted after evaluation by transperineal ultrasound or vaginal examination.

Secondary

MeasureTime frameDescription
Use of Oxytocin for Labor AugmentationDuring labor (up to delivery)Proportion of participants who receive oxytocin for augmentation of labor following initial triage evaluation.
Time from Admission to DeliveryFrom hospital admission to time of delivery
Mode of Delivery (as recorded in the medical record)At birthMode of delivery will be recorded from the medical record and categorized as spontaneous vaginal delivery, assisted vaginal delivery (instrumental), or cesarean section.
Number of Vaginal Examinations PerformedFrom hospital admission for labor to delivery

Countries

Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026