For many women, childbirth is a wonderful experience. Everything goes well, and there are no issues. However there are number of women who experience trauma to the pelvic floor muscles, sustained during vaginal delivery.
How many does this affect?
We know that around 90% of women sustain some degree of tearing of the perineum during a vaginal birth. (The perineum is the skin between the vagina and the anus). Up to 7% of these women sustain a 3rd or 4th degree tear. This is where the tearing extends down to the anal sphincter, tearing part way through the sphincter muscles and in some cases right through.
Avulsion injuries, where the pelvic floor muscles are partially torn from the bone, affect 10 to 35% of women. A further 28% experience micro trauma to the pelvic floor muscles, but not full tearing from the bone.
What can go wrong?
There are four situations I want to discuss, in terms of how the pelvic floor may be affected after a vaginal birth:
1.The pelvic floor has been stretched, but there is no damage.
It would be great if these women were checked and taught how to strengthen their pelvic floor muscles – so they get back to pre-birth strength and function, before they return to exercise, or daily activities that may load the area. Without a strong supportive pelvic floor, these women may be at risk of prolapse or bladder incontinence.
2.There is obvious damage.
In these cases, injuries are diagnosed at the time of the birth, and repaired. These women should all be offered pelvic floor rehabilitation. Stitching and repair does not necessarily mean that the muscles will function correctly. Pain and injury can cause inhibition of muscles, and they have also been stretched during the delivery.
3.There are no symptoms, and no damage is seen, BUT there is a pelvic floor muscle injury.
If the pelvic floor muscles are damaged or torn from the bone during the delivery, the damage is not seen from the outside, so is therefore not diagnosed at the time. These injuries can be picked up if a check is done after six weeks, via a vaginal examination. Confirmation requires ultrasound or MRI imaging, however in most cases this is not necessary as people with specific training in pelvic floor muscle assessment will be able to detect changes in the muscle.
4.The pelvic floor is intact, and there is no significant perineal tearing but there is still some damage to the anal sphincter muscles.
This can occur as a result of the shearing and stretching or pressure that occurs as the baby comes down through the vaginal canal. Some of these women may have issues with bowel control immediately. We know from research studies though, that there are women who sustain these injuries, but have no symptoms at the time, and it is not diagnosed. Even though the sphincter muscles will now be weaker, there may be enough strength left for them to get by without having any faecal incontinence. However, pressure from daily activities over their lives, as well as normal age-related and menopause changes, can lead to weakening of these muscles. These women may begin to experience bowel urgency and / or leakage, up to 20 or 30 years later. Ultrasound images confirm damage to the sphincter muscles, caused during childbirth but only now causing symptoms.
If these women had been assessed at the time, and taught how to strengthen the muscles and get them functioning at their own personal maximum level, they may then not weaken as much when normal age-related reduction in muscle strength occurs. This could potentially help prevent bowel leakage later in life.
What can be done?
I would love to see a situation where all women are assessed, and the pelvic floor muscles are checked, following childbirth. Trained Pelvic Health Physiotherapists have skills and expertise in this area and are able to help, giving women confidence that the pelvic floor is the best it can be. We can also teach them how to make lifestyle adjustments, and to modify physical exercise if necessary so that they are aware of how to help prevent pelvic floor problems over the course of their lives.
For more information about our pregnancy and postnatal assessment click here.