Yesterday I wrote about childbirth injuries. They’re common, lead to life long disability and distress and are a subject of deep embarrassment for many women.
I discussed the two most serious forms of childbirth injury: obstetric fistula, a hole between the vagina and the bladder or rectum or both; and severe vaginal tears that can result in the vagina and rectum becoming one passage. It’s not difficult to envision why either of those injuries lead to incontinence since urine and stool are released directly into the vagina and then dribble out.
As I explained, such injuries are now relatively uncommon. Fistulas are usually the result of prolonged obstructed labor and with the easy availability of C-sections they are rare. Vaginal tears, including severe vaginal tears, are still common but carefully repairing them with extensive suturing generally prevents incontinence.
Many readers might have wondered: I only had a minor childbirth injury so why am I incontinent?
The reason is because childbirth causes injuries that may not be visible, or the repair of a visible injury may be inadequate.
To understand the problem you need to understand how we achieve continence in the first place.
Outflow from both the bladder and the rectum is controlled by sphincters. A sphincter is a ring of muscle that can open and close in response to conscious or unconscious signals.
Babies are incontinent of both urine and stool, but neither is constantly dribbling. That’s because unconscious signals keep both the bladder and rectum closed until they are full. Only then will the appropriate sphincter open, releasing the contents. Then the sphincter will close until the organ is once again full.
Over time toddlers acquire the mature neurological function need to take conscious control of the bladder and anal sphincters. When continent children and adults feel the urge to void they can override the unconscious signals for the sphincters to open. In other words, they can “hold it.” But in order for them to do so, the sphincters themselves must be undamaged. Childbirth can lead to invisible injuries to the sphincters.
There’s a critical distinction to keep in mind. Bowel incontinence is nearly always the result of an injury that can be repaired while incontinence of urine may be the result of an injury that cannot be easily repaired.
The image below shows a third degree vaginal tear. You can see the muscles of the vagina have torn as well as the sphincter around the anus. Unless the sphincter is repaired, the woman will have permanent bowel incontinence. It’s relatively easy to tell the difference between the vaginal muscles and the anal sphincter in the picture, but in real life it can be quite difficult.
If there is any question, the provider should put a finger in the anus to determine if the sphincter is intact. If it has been torn, it can be repaired with sutures. An inexperienced provider may fail to recognize that the sphincter has been torn and may repair only the vaginal muscles. If you were to look at the repaired area with a mirror, it would look perfectly normal, but because the sphincter has been torn, there is no way to prevent the contents of the rectum from leaking out or being expelled. If that’s the cause of the bowel incontinence, it must be completely repaired, typically requiring surgery.
Urinary incontinence is different.
Urinary continence is controlled by the urethral sphincter. As shown in the image below, the sphincter’s ability to close off the bladder depends in large part on the relationship between the bladder and the urethra. The bladder is held in place by the ligaments and muscles of the pelvic floor. Vaginal birth (and to a lesser extent pregnancy itself) can stretch these ligaments and muscles causing the bladder to fall. The sphincter is still intact so urine doesn’t dribble out. But when the pressure on the bladder is increased by coughing, sneezing or physical exercise urine may escape. This is known as stress urinary incontinence and is the most common form of incontinence in women of childbearing age.
The maximum stretching of ligaments and muscles occurs at the time of vaginal birth. In the aftermath, the ligaments and muscles can regain some of their tone. That’s why incontinence in the first few days or weeks after birth can eventually resolve. If you are incontinent of urine at your 6 week check up, you should definitely tell your provider. He or she may suggest that you wait a little longer to see if you recover more muscle tone. Alternatively your provider may recommend Kegel exercises or pelvic physical therapy to strengthen the muscles of the pelvic floor.
How do childbirth interventions affect childbirth injuries? On the one hand, C-sections can prevent many childbirth injuries entirely. On the other hand, interventions like forceps can dramatically increase the risk of childbirth injuries. That’s not surprising when you consider that it is the passage of the baby’s head that leads to the injuries. When you apply forceps to the head, the effective size is increased and the risk of injury is increased, too. Forceps rotations (turning the baby’s head from an incorrect position to a correct position with the forceps) increases the risk of childbirth injury even more.
How about episiotomies?
The rationale for episiotomy is the belief that cutting through the perineal muscles to enlarge the vaginal opening would reduce both the stretching of the muscles and prevent major tears. Unfortunately, that’s not what happens. Cutting into the perineal muscles appears to increase the risk of severe tears; that’s why routine episiotomy is no longer recommended.
There is one exception, though. A mediolateral episiotomy (a cut angled toward the side) reduces the risk of childbirth injuries. Mediolateral episiotomies are much more painful than typical (median) episiotomies so they are rarely used.
So the role of childbirth interventions is paradoxical. C-sections reduce the risk of childbirth injuries, while vaginal delivery increases the risk of injury and forceps and episiotomy increase that risk even further. Women should be counseled about the risks of vaginal delivery in the same way they are counseled about the risks of C-section.
Moreover, efforts to decrease the C-section rate by replacing C-sections with forceps deliveries are not necessarily in women’s best interest. Yes, surgery has real risks, but the risk of incontinence (not to mention pelvic pain and sexual dysfunction) is one that cannot and should not be ignored.
It should be up to individual women to decide, based on their personal priorities, which mode of birth they prefer. A woman who prioritizes avoiding childbirth injuries should be able to choose a C-section in the absence of other medical indications.
Childbirth is inherently dangerous for babies and for mothers and the risk of death is not the only risk. The right to bodily autonomy means that women should weigh the risks for themselves, and that vaginal birth should be recognized not as a goal, but as an option with significant downsides.
