The Patient Positioning for Perineal Protection Study

Study Overview
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Brief Summary
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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
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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.

Official Title
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The Patient Positioning for Perineal Protection Study

Conditions
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Perineal Tear, Delivery; Trauma, Perineal Laceration

Intervention / Treatment
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* Other: Hip extension
* Other: Usual Care


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Patients will be assigned to usual care or hip extension at the time of delivery of the fetal vertex
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Usual care<br>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. | Other: Usual Care<br>* Hips positioned in the usual care position per provider preference at the time of vaginal delivery<br>|
| Experimental: Hip extension<br>Patients in this arm will be randomized to hip extension at the time of crowning of the fetal vertex during vaginal delivery. | Other: Hip extension<br>* Hips extended at the time of vaginal delivery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Classification of perineal laceration | The degree of perineal laceration as classified by the American College of Obstetricians and Gynecologists (ACOG) classification system | At the time of vaginal delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of OASIS laceration | Number of obstetric anal sphincter injury lacerations compared to all deliveries | At the time of vaginal delivery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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perineal tear, perineal laceration, vaginal delivery, delivery position