INTRODUCTION TO PREGNANCY INCONTINENCE
Pelvic floor disorders include conditions such as pelvic organ prolapse, pregnancy incontinence, and fecal incontinence. This is more common than most women are aware of. Studies show that:
- one-third of adult women in the United States are affected with pregnancy incontinence, with considerable impact on their quality of life
- 12 percent of women will need surgery
- approximately 17 percent of these women require re-operation.
Considering how common these pelvic floor conditions are, it is important to determine if there are causes that can be predicted and hopefully help in preventing them. We will focus mainly on the bladder conditions such as urinary incontinence because pelvic organ prolapse is not as commonly reported or treated. Most women with prolapse either have no symptoms or are not advised of the condition during routine exams.
One risk factor that is commonly considered to be causative is pregnancy and childbirth.
MECHANISMS OF PELVIC FLOOR INJURY
Clinical anatomy of the pelvic floor
The pelvic floor is primarily made up of the levator ani, urethra, and anal sphincter muscles. These muscles are surrounded by connective tissue that provide support and attach to the pelvic bones. The muscles are controlled by the spinal cord nerves found in the sacrum.
Effect of pregnancy and childbirth
Causes of injury to the tissues and muscles are associated with stretch during the entire pregnancy and labor, compression of nerves during pushing, and tearing of ligaments and muscles during delivery. Episiotomies and use of forceps can cause direct damage to the muscles, supporting tissue, and nerves. Healthy nerve and muscle function are important for lifelong use of the muscles for support.
The baby’s head can stretch and compress the blood flow that supplies the nerves. This can cause nerve function to weaken. With prolonged compression, the nerve can die.
Studies have shown that stress urinary incontinence will persist if the nerve is completely cut in half, but resolves if it is limited to compression injury. This may explain why some women recover after pregnancy while others begin suffering with lifelong urinary incontinence. Most women will have their muscle and nerve damage resolve during the first year after delivery. This explains why some women will show improvement of their bladder control symptoms during that time.
Injury to the Kegel and pelvic floor muscles
The levator ani muscle is composed of several muscles working together. It is more commonly referred to as the Kegel muscles. They form a U-shaped hammock around the pelvic floor. At rest, the Kegel muscle complex keeps vaginal opening closed, preventing the pelvic floor organs from falling out. During a Kegel squeeze, there is increased pressure further closing the urethra, vagina, and rectum. Loss of Kegel strength and function may result in a widening of the vaginal opening and a pushing down of the pelvic organs (pelvic organ prolapse).
MRI and ultrasound studies show that the levator muscles may tear completely off the pubic bone after delivery. This occurs by the baby’s head. This has been shown to happen during child birth 20% of the time, but not during cesarean deliveries. Forceps further increase the risk of this occurring. This can also result in prolapse of the pelvic floor organs (bladder, vaginal walls, rectum, and uterus). Pelvic floor muscle strength has also been shown to decrease after vaginal delivery.
The episiotomy is another example of possible injury to the muscles of the pelvic floor. Studies have shown that there is a decrease in pelvic floor muscle strength after delivery, but when compared to natural tears that occur in labor, there was no difference noted. Unfortunately, there is no proven method to prevent the injuries, aside from kegel exercises and pelvic floor physical therapy. Having an exam to assess pelvic floor muscle strength in the postpartum period should be standard of care to help improve recovery.
APPROACH TO PREVENTION OF PREGNANCY INCONTINENCE
So what are some possible things doctors can do during and after pregnancy to help women decrease the risk of pregnancy incontinence? Many treatment and prevention strategies have been proposed but it is unsure how effective they.
Preventative pelvic floor muscle exercises
Pelvic floor muscle exercises (PFME) can be performed while you are still pregnant to help decrease the risk of pregnancy incontinence in the postpartum period. This will help reduce the amount of time a woman has to suffer with the urinary incontinence, but not the overall risk of having it
Another thing to keep in mind is that if you do suffer an injury (natural tear or episiotomy in labor), it is most likely wise to wait for 6-8 weeks before resuming a Kegel exercise program. During this time, it is best to rest the muscles as they heal, and only start an exercise program to increase strength once the healing is complete.
While there is an association between vaginal delivery and increased risk of injury, most doctors do not recommend having a cesarean delivery to prevent and pregnancy incontinence. This is something that you can speak to your doctor about and discuss the risks of surgery with the potential risk of future surgery for pelvic floor disorders.
Management options during Vaginal delivery
If you are going to have a vaginal delivery, some options to decrease the risk of pregnancy incontinence and pelvic organ prolapse are:
- Avoid prolonged labor
- Discuss with your physician about the avoiding the use of forceps during delivery
- Use of episiotomy – Episiotomy may not prevent urinary incontinence or prolapse, and may increase the risk of fecal incontinence.
Limiting number of children
The biggest risk of pelvic floor disorders comes with the first birth. The first delivery increases your risk of having pregnancy incontinence or pelvic organ prolapse by 50%, but each additional child only increases the risk by 10%. This is a decision for the family to make prior to having your first child.