The Patient Positioning for Perineal Protection Study

NCT ID: NCT04616170

Last Updated: 2025-07-17

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 1206 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-04-05
• Study Completion Date: 2025-07-11

Brief Summary

It is common practice for practitioners to instruct patients to forcibly flex the hips at the time of delivery of the fetal vertex. Though this is commonplace, it is reasonable to assume that this forced stretching of the perineum at the time of fetal vertex emergence could potentially lead to higher rates of severe lacerations and their sequelae. This study will examine whether extending the hips, as compared to usual care, at the time of crowning of the fetal vertex during vaginal delivery decreases maternal perineal trauma among nulliparous women.

Detailed Description

Perineal trauma at the time of vaginal delivery is a significant cause of maternal morbidity including vaginal pain, dyspareunia, urinary incontinence, infection, and social isolation in severe cases. There are well known risk factors in the literature for OASIS (obstetric anal sphincter injuries), however, this literature is by no means comprehensive. A prior RCT in 2012 looked at the role of patient positioning at the time of pushing and delivery to determine whether stirrup positioning and forced hip flexion leads to higher rates of any perineal tears. The study concluded that stirrup positioning did not lead to higher rates of perineal tearing but was not powered to evaluate the role of positioning on OASIS tears or on postpartum perineal morbidity.

In addition to lacking data with respect to patient positioning, data is limited regarding perineal morbidity beyond the traditional grading system of 1st, 2nd, 3rd, and 4th degree tears. 3rd and 4th degree lacerations are labeled as OASIS, however, perineal morbidity can result from "lower" orders of perineal tearing at the time of delivery. Prior studies have tried to illustrate various subsets of second degree lacerations in an attempt to subdivide 2nd degree lacerations into categories of severity, however, little has been done in practice with this form of division and little is written on the topic of perineal morbidity beyond OASIS tears.

It is common practice for practitioners to instruct patients to flex the hips at the time of delivery of the fetal vertex. Though this is commonplace, it is reasonable to assume that this stretching of the perineum at the time of fetal vertex emergence could potentially lead to higher rates of severe lacerations and their sequelae. The closest studies to examine this have been in comparing women who deliver in the squatting position compared to in lithotomy. Those who deliver in squatting positions have been found to have deeper perineal lacerations, which demonstrate the possibility that forced flexion at the hips could lead to the same outcome in the lithotomy position. Should research show an increased risk of morbidity with this near universal positioning practice as compared to hip extension, this study could change practice patterns for the betterment of patients worldwide.

Conditions

Perineal Tear; Delivery; Trauma; Perineal Laceration

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Usual care

Patients in this arm will be randomized to the routine positioning instructions given at the time of crowning of the fetal vertex during vaginal delivery.

Group Type: ACTIVE_COMPARATOR

Usual Care

Intervention Type: OTHER

Hips positioned in the "usual care" position per provider preference at the time of vaginal delivery

Hip extension

Patients in this arm will be randomized to hip extension at the time of crowning of the fetal vertex during vaginal delivery.

Group Type: EXPERIMENTAL

Hip extension

Intervention Type: OTHER

Hips extended at the time of vaginal delivery

Interventions

Hip extension

Hips extended at the time of vaginal delivery

Intervention Type: OTHER

Usual Care

Hips positioned in the "usual care" position per provider preference at the time of vaginal delivery

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Nulliparous women
• Non-anomalous fetuses
• Term gestation
• Vertex presentation
• Eligible for trial of labor

Exclusion Criteria

• Multiparous women
• Prior perineal malformations
• History female genital mutilation
• Prior perineal surgery
• Anomalous fetuses
• Multiple gestations
• Fetal status incompatible with labor

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

Massachusetts General Hospital

OTHER

Sponsor Role: lead

Responsible Party

William H. Barth, Jr., MD

Vice Chair, Obstetrics (Chief of Obstetrics)

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Marti D Soffer, MD MPH

Role: STUDY_DIRECTOR

Massachusetts General Hospital

William H Barth, MD

Role: PRINCIPAL_INVESTIGATOR

Massachusetts General Hospital

Locations

Massachusetts General Hospital

Boston, Massachusetts, United States

Countries

United States

Other Identifiers

2020P003603

Identifier Type: -

Identifier Source: org_study_id