by Dr Michele Brown, MD OBGYN
The Economy is not the Only Thing Falling…
Pregnancy, probably the most momentous experience in a woman’s life, can have lifelong negative effects. The trauma that can occur from a routine vaginal delivery can result in damage to pelvic organs, such as the uterus, bladder and/or rectal organs with resulting pelvic dysfunction. Some studies have reported that approximately 46 % of women acknowledge some sort of pelvic floor dysfunction. If constipation and obstructed defecation are included, studies have shown that over 67.7% of women reporting problems with pelvic floor disorder. This can result in poor quality of life and often requires future surgical correction. The blog this month will discuss why this occurs, what can be done to prevent this, and whether routine elective C-sections prevent women from experiencing these problems.
What is the definition of pelvic floor dysfunction?
Pelvic floor dysfunction refers to multiple conditions such as urinary incontinence, pelvic organ prolapse, sensory and emptying abnormalities of the lower urinary tract, defecatory dysfunction, sexual dysfunction, and several chronic pain syndromes.
What are the common risk factors associated with pelvic floor dysfunction?
The most common risk factors causing pelvic dysfunction include:
1. Trauma from routine childbirth: Babies with large head circumference greater than 35 cm increase risk of maternal trauma. Damage of the anal sphincter can occur secondary to visible lacerations or episiotomy after childbirth but can also occur with an intact perineum. Over 35% of primiparous women suffer some degree of damage to the external anal sphincter persisting until 6 months post vaginal delivery which can affect continence.
2. Prolonged vaginal delivery: Second stage of labor (pushing phase) greater than 90 minutes doubles risk.
3. Large birth weight: Macrosomia or birth weights greater than 4.5 kg.
4. Use of forceps and vacuum deliveries: Instrumental deliveries can result in greater risk of injury to the anal sphincter and for later prolapse. Multiple spontaneous lacerations following delivery can also increase the risk of injury. (Nov 2012 Ob/Gyn )
5. Multiparity: First delivery is the most destructive to the pelvic floor but multiple pregnancies add to the trauma.
6. Older maternal age at delivery: Mothers older than age 35 have poorer tissue integrity and elasticity.
7. Obesity: Mothers with a BMI greater than 30.
8. Increased abdominal pressure: Coughing, chronic lung disease, obesity, labor intensive occupations.
9. Spinal cord injury.
10. Genetic and or family predisposition: Pelvic dysfunction has occurred in women with no history of vaginal birth but a genetic predisposition seen in other family members due to poor collagen with a genetic tendency for poor pelvic support.
11. Previous pelvic surgery: Previous fistula repair or surgery of the bladder and/or rectum.
12. Low socioeconomic status: Effects tissue integrity and strength, perhaps secondary to diet.
14. Race: White, Asian, and Hispanic women are more prone to injury compared to African-American women due to collagen differences.
What is the mechanism causing pelvic floor dysfunction?
The endopelvic fascia, which supports the pelvic floor, is comprised of muscles, ligaments, and connective tissue. Integrity of nerves is also essential for maintaining the support structure, function and continence mechanisms. Women who experience dysfunction have a loss of this support, especially the integrity of the levator ani muscles which is the main muscle responsible for the support of the pelvis. It is believed that vaginal delivery damages the fascial support in addition to the nerves to the pelvic floor. The supporting structures of the uterus, which are the uterosacral ligaments and parametrial ligaments, are unable to maintain the support of the uterus and nearby structures causing even further damage. Damage to these fascia, ligaments, muscles and peripheral nerves caused by stretching, compression, muscle tearing and nerve injury, both from the pregnancy itself and the delivery, can cause a loss of pelvic organ support and also a loss of control of continence mechanisms.
What are the chances that a woman will need surgery to correct pelvic organ prolapse or incontinence in her lifetime?
There are approximately 135,000 women who need surgery for urinary incontinence and 225,000 women who will need surgery for pelvic organ prolapse each year in the United States. Approximately 4-25% of first time mothers have fecal incontinence postpartum: 26% of women develop urinary incontinence and 52% have some degree of anterior vaginal wall prolapse after a vaginal birth. (Bortolini Int Urogyn 2010)
Vaginal deliveries can cause defects in the levaor ani muscle. Gaps greater than 25 cm are abnormal. The levator ani has 3 components–the iliococcygeus , the pubococcygeus, and the puborectalis portions. Defects can occur in the puborectalis portion of the levator muscle causing rectal prolapse. Injuries can also occur to the pubovisceral portion of the levator ani which can cause stress incontinence. About 10% of women who deliver undergo pelvic surgery and about 30% of them have repeated corrective surgeries.
When do patients recuperate muscle strength after delivery?
Patients do not recuperate muscle strength until 8 months post-partum. Thirty four percent of patients are not able to contract pelvic muscles voluntarily until 6 weeks postpartum. Approximately 70% of women with SUI during pregnancy spontaneously resolve their symptoms postpartum. However, if urinary incontinence persists 3 months after delivery, this is one of the most important risk indicators for urinary incontinence in later life. Approximately 90% of women with urinary incontinence 3 months after delivery will be incontinent 5 years afterward.
Is there a way to prevent pelvic floor dysfunction?
Determining which aspects of childbirth contribute most to pelvic floor disorders and investigating how obstetrical care can be modified to reduce the incidence of pelvic floor dysfunction is an area for future investigation. In addition, patients can take an active role in also helping to prevent pelvic dysfunction.
- Pelvic exercises: Arnold Kegel in 1948 developed pelvic floor exercises to strengthen the muscles. Kegel exercises can be done both during pregnancy and postpartum. Opinions differ as to whether these exercises are really useful in preventing pelvic floor dysfunction.
- Perineal massage: reduces the chance of suturing and episiotomy at delivery
- Control BMI: avoid obesity and eat protein containing foods which help with healing of post-delivery injury
- Stop smoking!
- Prevent constipation during pregnancy to increase bowel muscle tone and strength
- Prevention of a prolonged second stage of labor (pushing) and avoiding use of instrumental deliveries might make vaginal deliveries safer and avoid long term sequellae of pelvic organ dysfunction.
- Training residents on the proper repair of episiotomies and rectal tears is also essential in the prevention of pelvic floor trauma. Good control of the fetal head at delivery is essential.
- Caesarean delivery, the “C-Section”This is controversial. Urinary incontinence still occurs in women who have had elective c-sections prior to labor. Some studies have shown elective c-section to be slightly protective for prevention of stress incontinence but less effective in preventing other forms of pelvic dysfunction. The morbidity of elective c- section must be taken into consideration and without unquestionable proof of the benefit in prevention of pelvic floor, one cannot advocate doing routine c-sections. To date the American College of Obstetrics and Gynecology does not advocate routine caesarean sections as a way to prevent pelvic floor injury.However, it is considered acceptable to offer consideration of an elective caesarean section to those women who have already sustained pelvic floor injury in a previous delivery or have undergone corrective surgery in the past. Issues always arise when it comes to offering an elective caesarean section to mothers with previous 3rd or 4th degree lacerations (rectal muscle or mucosa tears) or women with mild stress incontinence as a result of a previous delivery. There is no stock answer; there is no general rule that applies. These cases must be evaluated on a case by case basis.
The pelvic support system weakens after childbirth, but in the majority of cases recovers after one year, regardless of mode of delivery. Risk factors for pelvic dysfunction include prolonged vaginal delivery, increased birth weight, enlarged head circumference and operative vaginal delivery. Exact cut off values for management of labor and vaginally delivering are still being developed and will probably never be applicable in every case. It must be realized that C- section is not completely protective against the development of pelvic floor dysfunction as individual structure, genetics, age, other factors mentioned above and the pregnancy itself all contribute to the outcome. Women should be reassured that the reduction in pelvic muscle function is often temporary and that a c-section to prevent its occurrence is not indicated. Regular use of pelvic floor exercises (Kegel) can have a beneficial effect on pelvic floor muscle function. As more older women give birth, we may see a higher incidence of pelvic floor dysfunction. In addition, as laparoscopic surgical techniques to repair these problems become more commonly available, more women will be able to undergo corrective procedures with minimal discomfort and less time lost from life activities.