Childbirth is an important event in a woman’s life. Vaginal childbirth is the most common mode of delivery and it has been associated with increased incidence of pelvic floor disorders later in life. In this article, the authors review and summarize current literature associating pelvic floor disorders with vaginal childbirth. Stress urinary incontinence and pelvic organ prolapse are strongly associated with vaginal childbirth and parity. The exact mechanism of injury associating vaginal delivery with pelvic floor disorders is not known, but is likely multifactorial, potentially including mechanical and neurovascular injury to the pelvic floor. Observational studies have identified certain obstetrical exposures as risk factors for pelvic floor disorders. These factors often coexist in clusters; hence, the isolated effect of these variables on the pelvic floor is difficult to study.

Purpose of review Pelvic floor disorders affect women of all ages and are associated with significant economic burden and poor quality of life. Current literature suggests an association between childbirth and these disorders. In this review, we summarize recent advancements in our understanding of this association. Recent findings Vaginal childbirth appears to be strongly associated with stress urinary incontinence and pelvic organ prolapse. There is less evidence to suggest an association between vaginal delivery and overactive bladder symptoms. History of more than one perineal laceration increases the likelihood of developing prolapse. Similar association has not been established for episiotomy. Disruption or denervation of structural components of pelvic floor support system, particularly levator ani muscle complex, is associated with later development of pelvic floor disorders. Imbalance in homeostasis of connective tissue remodeling of the vaginal wall from overstretching during childbirth is another possible mechanism. Summary Pelvic floor disorders represent a significant health problem affecting women of all ages. Identification of potential modifiable risk factors and advancement in understanding of the underlying pathophysiology is crucial for primary and secondary prevention of these disorders and for improvement in treatment strategies.

Objective Using three-dimensional transperineal ultrasound, we compared the prevalence of levator ani muscle injury after forceps with vacuum-assisted vaginal delivery. Methods This was a retrospective cohort study. Women who experienced at least one forceps delivery (across all deliveries) were compared to women who had at least one vacuum birth. On average, participants were 10 years from the index delivery. Three-dimensional transperineal ultrasound volumes were captured as cine loops at rest, with Valsalva and with pelvic floor muscle contraction. The primary outcome was levator ani muscle avulsion. Secondary outcomes included hiatal diameter and area. Prevalence of pelvic floor disorders was also compared between the two delivery groups. Results Among 45 participants in the forceps group and 28 participants in the vacuum group, there were no differences between groups in maternal age at first delivery, parity, body mass index, birth weight, episiotomy, and duration of second stage. History of anal sphincter laceration was more common in the forceps group. The prevalence of levator ani muscle avulsion was significantly higher after forceps compared with vacuum delivery {22/45 (49%) versus 5/28 (18%), p=0.012, prevalence ratio = 2.74 (95% CI: 1.17, 6.40), odds ratio = 4.40 (95% confidence interval: 1.42, 13.62)}. Controlling for delivery type, levator ani muscle avulsion was associated with symptoms of prolapse (p=0.036), although objective evidence of prolapse was not significantly different between groups (p=0.20). Conclusion Ten years after delivery, the prevalence of levator avulsion is almost tripled after forceps compared with vacuum-assisted vaginal delivery.