Vaginal Birth and Pelvic Floor Trauma

Abstract

Over the last two to three decades, a growing body of research has shown that vaginal childbirth is more traumatic to mothers than generally assumed. Apart from obstetric anal sphincter tears which have been extensively studied, trauma to the levator ani muscle is a form of maternal injury that is less well recognised and often undiagnosed. In the context of an increasing push towards vaginal birth, this article will review the recent literature to better inform health care providers regarding the significance of pelvic floor trauma. Imaging studies have shown that levator avulsion, where the puborectalis muscle has detached from the os pubis, occurs in up to 1/3 of vaginally primiparous women, depending on demographic factors and obstetric management. Forceps is a well-established risk factor for levator avulsion with an odds ratio of 4–5 compared to vacuum, which does not seem to convey additional risk over unassisted vaginal birth. Levator injuries are significantly associated with pelvic organ prolapse and treatment failure. Such trauma can also lead to significant psychological morbidity, up to and including post-traumatic stress disorder. Antenatal prediction does not appear feasible. Modification of obstetric practice by abandoning forceps would significantly reduce pelvic floor trauma and the future need for prolapse surgery. Vaginal childbirth is more traumatic than commonly assumed. Levator trauma is associated with significant physical and psychological morbidity. Perinatal health care providers need to understand and recognise the significance of maternal birth trauma and its potential impact on women’s health.