10.1016/j.ajog.2023.11.1253
This review article was published this week in the American Journal of Obstetrics and Gynecology.American Journal of Obstetrics and Gynecology. Unfortunately, it is behind a paywall so you have to pay to read it unless you or your organisation have a subscription. It is an absolute bugbear of mine when research is locked away so I generally avoid sharing these types of articles here. However, this one does have some interesting insights so I thought I’d share a longer summary of it here.
The article describes the pelvic floor injuries that can occur in childbirth and the mechanisms of injury. It also covers how these injuries might be reduced in the future.
Here are some key points:
Vaginal birth is the single most important modifiable risk factor for the development of Pelvic Floor Disorders—especially pelvic organ prolapse, with 1.6 times more surgeries than stress urinary incontinence and 9.5 times more surgeries than faecal incontinence performed annually.
Over the last 2 decades, ultrasound and magnetic resonance imaging (MRI) studies of the deeper pelvic floor structures, such as the levator ani muscle, have shown that this muscle can be severely injured during vaginal delivery in up to 19% of women, which is 6 times more likely to occur than in anal sphincter injury. This injury does not recover and is a leading cause of PFDs later in life.
It is now clear that hiatal enlargement is the single most important birth-related factor associated with pelvic organ prolapse. Increasing hiatus size is clearly associated with an increasing likelihood of developing prolapse. Hiatal enlargement precedes the occurrence of prolapse, indicating a potentially causal relationship.
The articles then consider ways to prevent these injuries, recommending ventouse over forceps, perineal massage or compresses, early induction of labour for large infants, slow gradual delivery and the use of improved measures to identify women at high risk of injury and offering caesareans where appropriate.
In regards to identifying women before labour who are almost certainly going to have an injury during birth and offer potential caesarean delivery, the article expands that this strategy would involve an ultrasound assessment in the third trimester of pregnancy to measure the size of the urogenital and levator hiatuses, arch of the pubic bones, and size of the foetal head. A table of risk can be generated with a woman’s risk of sustaining a permanent injury. Women with a value significantly <1 could be evaluated for potential caesarean delivery—especially if they only plan 1 birth or are at increased risk because of older age. Proof of concept using postnatal foetal head size coupled with antenatal hiatus and pelvic bone measurements demonstrated an 80% ability to predict injury.
Women’s reluctance to seek help for pelvic floor conditions stems from the feeling that those are part of the process of childbearing and from low awareness, poor knowledge of PFDs, embarrassment, or feeling that they should not trouble health professionals. Thus, it is important to educate women on the implications of vaginal delivery on the pelvic floor to empower and improve their ability to make informed decisions regarding their perinatal and postpartum care.
DeLancey JOL, Masteling M, Pipitone F, LaCross J, Mastrovito S, Ashton-Miller JA. Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it? Am J Obstet Gynecol. 2024 Jan 1:S0002-9378(23)02116-6. doi: 10.1016/j.ajog.2023.11.1253. Epub ahead of print. PMID: 38168908.
https://www.sciencedirect.com/science/article/pii/S0002937823021166