Undergraduate Honors Theses

Thesis Defended

Spring 2016

Document Type


Type of Thesis

Departmental Honors


Integrative Physiology

First Advisor

Dr. Teresa Foley

Second Advisor

Dr. Matthew McQueen

Third Advisor

Dr. David Sherwood

Fourth Advisor

Ms. Heidi Bustamante

Fifth Advisor

Dr. Lorraine Bayard de Volo


Spontaneous, natural perineal trauma is a common complication faced by women following vaginal delivery. Most women in Western countries deliver in the supine position, which is typically accompanied by non-ambulatory movement restriction. The current literature suggests this position provides little physiological benefit to the mother. Therefore, this systematic review aimed to investigate, 1) restrictive, non-ambulatory Western birth practices in terms of perineal integrity, 2) freedom of movement birth practices in terms of perineal integrity. Seven randomized controlled trials were evaluated. Each study compared a non-supine position, either the squatting or sitting position, to the supine position and reported the incidence of various degrees of spontaneous perineal tears. A meta-analysis was performed and the relative risk was calculated for each study. A random-effects summary estimate was calculated and the overall relative risk was reported as 4.4108 with a 95% confidence interval of 3.1514-6.1736 and a p-value of <0.0001 (alpha level of <0.05). Results suggest that the supine position is associated with reduced spontaneous perineal trauma. Future research is needed to determine the physiological benefits of restrictive, non-ambulatory and freedom of movement birth practices on a wide variety of maternal outcomes.