Best Evidence: Pelvic Floor 



Best evidence: When making important maternity decisions, women should have information from the best available research about the safety and effectiveness of different choices. In general, we can be most confident about results of systematic reviews that summarize randomized controlled trials (or RCTs, a type of study).

Unfortunately, for many decisions we must rely on less definitive research; and many important questions even in the case of widely used drugs, tests and procedures have hardly been studied at all. Although this situation is discouraging, an awareness of weak or missing evidence can help you make informed choices about care.

A series of systematic reviews, listed at the end of this page, were available to help clarify the best current knowledge about causes of and ways to prevent pelvic floor injury.

KEY MESSAGES ABOUT PELVIC FLOOR DYSFUNCTION AND GIVING BIRTH

What are some concerns about effects of anal muscle tears?

What are some concerns about effects of midline episiotomy?

What are some concerns about effects of mediolateral episiotomy?

What are some concerns about the effects of vacuum extraction or forceps on the pelvic floor?

What are some concerns about effects of continuous electronic fetal monitoring?

What are some concerns about effects of epidural analgesia?

What is a concern about effects of fundal pressure (a caregiver pressing on the woman's abdomen to help move the baby out)?

What is a concern about effects of forceful sustained caregiver-directed pushing (versus pushing guided by a woman's own "urge to push" reflex)?

What are some concerns about pushing your baby out while lying on your back (versus pushing in various upright or side-lying positions)?

What is the benefit of pelvic floor exercises (kegel exercises) for preventing or relieving leaking urine when the pelvic floor is stressed by coughing, sneezing, laughing, or lifting heavy objects (urinary stress incontinence)?

Is using weighted vaginal cones or electrical stimulation better than kegel exercises for improving or curing urinary stress incontinence?

Does combining kegel exercises with vaginal cones, electrical stimulation, or biofeedback do better at improving or curing urinary stress incontinence than a program of kegel exercises alone?

What is the benefit of a routine of perineal massage in the final weeks of pregnancy?


KEY MESSAGES ABOUT PELVIC FLOOR DYSFUNCTION AND GIVING BIRTH

See details about these and other effects after the following summary list.

Despite limitations of the best available research, the following conclusions seem clear:

  • Episiotomy: The routine or frequent use of episiotomy (cutting the vaginal opening to enlarge it for birth) has no advantages and many disadvantages. These include painful vaginal area, problems with episiotomy healing, and painful sexual intercourse. Midline episiotomy (the cut goes straight back) can lead to tears into the anal muscle.
  • Anal muscle injury: Women with anal muscle injuries are more likely to develop leaking gas, a sence of urgency about elimination, or more rarely leaking feces (bowel incontinence).
  • Assisted vaginal birth: Compared with women giving birth by their own efforts (spontaneous vaginal birth), women who have vacuum extraction or forceps deliveries (assisted vaginal birth) are more likely to experience anal muscle tears, infection, pain, bowel problems, urinary incontinence (with forceps only), bowel incontinence, and sexual problems.
  • Vacuum extraction vs. forceps: Vacuum extraction is less likely to harm the pelvic floor than forceps delivery.
  • Continuous electronic fetal monitoring to keep track of the fetal heart rate leads to more assisted deliveries without any improvement in the number of babies born in poor condition than intermittent monitoring.
  • Epidural analgesia increases risk for more assisted deliveries and tears into the anal muscle.
  • Kegel exercises: Doing pelvic floor exercises (kegel exercises) regularly in pregnancy and after birth can help prevent, improve or cure urinary incontinence. An intensive program is better than a less intensive program.

On the rest of this page, you will find details about effects of:
You will also find information about effects of tears that extend into the anal muscle.

MORE DETAILED INFORMATION ABOUT CAUSES OF AND WAYS TO PREVENT PELVIC FLOOR INJURY AROUND THE TIME OF CHILDBIRTH
Click below on VERY HIGH, HIGH, etc. to understand difference in level of risk between care options.

What are some concerns about effects of anal muscle tears?

  • delayed healing: women who have an anal muscle injury are more likely to have a wound that hasn't closed or an infection 1 to 2 weeks after the birth compared with women without anal muscle injury.
    Added likelihood for a woman with anal muscle injury: VERY HIGH for delayed healing
  • bowel incontinence: anal muscle injury can lead to leaking gas, a sense of urgency about elimination, or more rarely leaking feces (bowel incontinence).
    Added likelihood for bowel incontinence with anal muscle injury cannot be determined from studies examined

What are some concerns about effects of midline episiotomy?

Both types of episiotomy can injure your perineum (the tissue between the vagina and the anus). With midline (also called median) episiotomy, the type usual in the U.S. and Canada, the cut is made from the back of the vaginal opening straight toward the anus (see images on Pelvic Floor Dysfunction page in Resources A-Z). Midline episiotomy increases risk for several problems:

  • tear that extends into or through the anal muscle:
    Added likelihood for a woman who has a midline episiotomy compared with no episiotomy: VERY HIGH for a tear extending into the anal muscle
  • delayed healing: women who have a midline episiotomy are more likely to have a wound that hasn't closed or an infection 1 to 2 weeks after the birth compared with women with no episiotomy.
    Added likelihood for a woman with midline episiotomy: HIGH for delayed healing
  • vaginal and perineal pain: as the depth of injury to the perineum increases from no injury at all (intact perineum) to spontaneous tear to episiotomy to tear into the anal muscle, the likelihood of experiencing severe pain 3 months after the birth or having pain most or all of the time also increases.
    Added likelihood for severe or long-lasting pain in a woman who has a midline episiotomy cannot be determined from studies examined
  • pain during first sexual intercourse: as the depth of injury to the perineum increases from no injury at all (intact perineum) to spontaneous tear to episiotomy to tear into the anal muscle, the likelihood of experiencing pain when resuming sexual intercourse also increases. Women with no injury to the perineum are also likely to resume sexual relations sooner and to say that any discomfort they experienced during intercourse was mild.
    Added likelihood for pain when resuming sexual intercourse in a woman who has a midline episiotomy cannot be determined from studies examined

What are some concerns about effects of mediolateral episiotomy?

With mediolateral episiotomy, which tends to be used outside of the U.S. and Canada, the cut is made back and off to one side (see images on Pelvic Floor Dysfunction page in Resources A-Z). A mediolateral episiotomy causes more bruising and tends to result in a thicker, harder scar and a worse cosmetic appearance compared with a midline episiotomy. Women also resume intercourse later with mediolateral versus midline episiotomies. A mediolateral episiotomy (vs. no episiotomy) does not help prevent a harmful tear into the anal muscle. Women who have a spontaneous tear do better in several areas compared with women who have a mediolateral episiotomy:

  • vaginal and perineal pain: women who have a mediolateral episiotomy are more likely to experience pain in the first few days after birth than women with a spontaneous tear (women who have no tear are much less likely to report significant pain on the first day after birth compared with women who have had a mediolateral episiotomy; up to half may report no pain at all).
    Added likelihood for a woman who has a mediolateral episiotomy compared with a woman who has a spontaneous tear: HIGH for needing pain medication in the first few days after birth
  • pain during intercourse: women who have a mediolateral episiotomy are more likely to experience pain during intercourse in the first 2 to 3 months after birth than women who have a spontaneous tear.
    Added likelihood for pain during sexual intercourse in a woman who has a mediolateral episiotomy compared with a woman who has a spontaneous tear cannot be determined from studies examined
  • poor early perineal healing: women who have a mediolateral episiotomy are more likely to have redness, swelling, and a wound that has not closed 5 days after birth than women who have a spontaneous tear.
    Added likelihood for a woman who has a mediolateral episiotomy compared with a woman who has a spontaneous tear: VERY HIGH for poor early perineal healing
  • infection: women who have a mediolateral episiotomy are more likely to develop an infection than women with a spontaneous tear.
    Added likelihood for a woman who has a mediolateral episiotomy compared with a woman who has a spontaneous tear: HIGH for developing an infection
  • abnormal long-term healing: women who have a mediolateral episiotomy are more likely to have scarring, healing with a puckered appearance, or pain with pressure on the scar at 2 to 3 months compared with women who have a spontaneous tear.
    Added likelihood for a woman who has a mediolateral episiotomy compared with a woman who has a spontaneous tear: HIGH for abnormal long-term healing

What are some concerns about the effects of vacuum extraction or forceps on the pelvic floor?

With growing recognition of the risks listed below, fewer than 6% of U.S. births now use vacuum extraction or forceps to help the baby out. Nonetheless, the potential benefits of assisted vaginal birth can outweigh the risks in selected situations and in skilled hands. Risks of the procedure can be reduced by avoiding episiotomy whenever possible.

(Note: In addition to its potential effects on the pelvic floor, described below, assisted vaginal birth has also been associated with increased risk for: excessive bleeding and transfusion, need for readmission to the hospital, dissatisfaction or disappointment with the birth experience, psychological trauma, and poor physical and social functioning in the early weeks after birth. Assisted vaginal birth also increases the likelihood of the baby having a brain injury or other nerve injuries. For more details, go to pages 26-27 in: What Every Pregnant Woman Needs to Know About Cesarean Section.)

Having an assisted vaginal birth (with vacuum extraction or forceps) rather than a spontaneous vaginal birth (with neither procedure) increases risk for the following problems:

  • tears in the perineum (the tissue between the back of the vagina and the anus) that extend into or through the anal muscle: a woman who has an assisted delivery (and especially a forceps delivery) is at increased risk for tears from the opening of the vagina back into the anal muscle, in comparison with a woman with spontaneous vaginal birth (research suggests that almost all of these serious tears can be avoided if women with assisted delivery do not also have an episiotomy).
    Added likelihood for a woman who has vacuum extraction: VERY HIGH to HIGH for a tear extending into the anal muscle
    Added likelihood for a woman who has forceps: VERY HIGH for a tear extending into the anal muscle
  • infection: a woman who has had assisted delivery appears to be at increased risk for infection in her uterus and iif she has had an episiotomy or a tear in her vaginal area for infection of that wound, in comparison with a woman with spontaneous vaginal birth.
    Added likelihood for a woman who has an assisted vaginal birth: VERY HIGH to HIGH for infection of the perineum; HIGH for infection within the uterus
  • vaginal and perineal pain: a woman who has had an assisted delivery is at increased risk for vaginal and perineal pain in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth.
    Added likelihood for a woman who has an assisted vaginal birth: VERY HIGH for a painful vaginal area
  • bowel problems: a woman who has had an assisted delivery is at increased risk for bowel problems of any sort in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth.
    Added likelihood for a woman who has an assisted vaginal birth: VERY HIGH to HIGH for bowel problems
  • urinary incontinence: a woman who has had a forceps delivery may be at increased risk for leaking urine (urinary incontinence) in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth (vacuum extraction does not appear to increase this risk).
    Added likelihood for a woman who has forceps cannot be determined in light of mixed results among studies
  • bowel incontinence: a woman who has had a forceps delivery is at increased risk for leaking gas or feces (bowel incontinence) in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth (vacuum extraction may or may not increase the risk of having this complication).
    Added likelihood for a woman who has forceps: VERY HIGH to HIGH for some leaking gas or stool in the period after birth
    Added likelihood for a woman who has vacuum extraction cannot be determined in light of mixed results among studies
  • hemorrhoids: a woman who has had an assisted delivery is at increased risk for hemorrhoids in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth.
    Added likelihood for a woman who has an assisted vaginal birth: VERY HIGH to HIGH for hemorrhoids
  • sexual problems: a woman who has had assisted vaginal birth is at increased risk for sexual problems (such as pain with intercourse) in the weeks and months after birth, in comparison with a woman with spontaneous vaginal birth.
    Added likelihood for a woman who has an assisted vaginal birth: VERY HIGH for sexual problems in the weeks and months after birth
  • poor overall functioning: a woman who has had an assisted delivery is at risk for poorer physical and social functioning in the early weeks after birth than a woman with spontaneous vaginal birth.
    Added likelihood for poor overall functioning cannot be determined from studies examined

What are some concerns about effects of continuous electronic fetal monitoring?

Women who have continuous electronic fetal monitoring to keep track of the baby's heart rate during labor (vs. intermittent monitoring at regular intervals) are more likely to have vacuum extraction or forceps deliveries. Despite this, babies are not born in better condition compared with women whose babies are monitored at regular intervals. Exceptions may be women who are at higher risk for complications, such as those who are being given high doses of synthetic oxytocin (Pitocin or "Pit") by IV drip to start or strengthen labor, are having an epidural, or are laboring with a uterine scar. Having continuous rather than intermittent monitoring increases risk for:

  • assisted vaginal birth:
    Added likelihood for assisted vaginal birth cannot be determined from studies examined

What are some concerns about effects of epidural analgesia?

An epidural can have indirect effects on the pelvic floor because it increases the likelihood of having a vacuum extraction or forceps delivery (assisted vaginal birth), which is usually given hand-in-hand with episiotomy. These procedures, especially when used together, increase the risk of anal muscle tears. Use of epidural analgesia increases risk for:

  • assisted vaginal birth:
    Added likelihood for assisted vaginal birth cannot be determined from studies examined
  • tears in the tissue between the vagina and the anus (perineum) that extend into or through the anal muscle:
    Added likelihood for assisted vaginal birth cannot be determined from studies examined

What is a concern about effects of fundal pressure (a caregiver pressing on the woman's abdomen to help move the baby out)?

Although more research is needed, this procedure appears to increase risk for:

  • tears in the tissue between the vagina and the anus (perineum) that extend into or through the anal muscle:
    Added likelihood for a woman who has fundal pressure: VERY HIGH for a tear extending into the anal muscle

What is a concern about effects of forceful sustained caregiver-directed pushing (versus pushing guided by a woman's own "urge to push" reflex)?

In some but not all studies, caregiver-directed pushing increases risk for:

  • tears in the tissue between the vagina and the anus (perineum) that require stitching or episiotomy:
    Added likelihood for a woman using caregiver-directed pushing: cannot be determined from studies examined

What are some concerns about pushing your baby out while lying on your back (versus pushing in various upright or side-lying positions)?

Women who push their babies out while lying on their back appear to be at increased risk for:

  • episiotomy:
    Added likelihood for a woman pushing on her back: HIGH for having an episiotomy
  • assisted vaginal birth:
    Added likelihood for a woman pushing on her back: HIGH for giving birth with vacuum extraction or forceps

What is the benefit of pelvic floor exercises (kegel exercises) for preventing or relieving leaking urine when the pelvic floor is stressed by coughing, sneezing, laughing, or lifting heavy objects (urinary stress incontinence)?

An intensive program of exercises appears to produce better results than one that is less intensive. Carrying out a program of kegel exercises appears to help:

  • prevent, improve or cure urinary incontinence after birth if done during pregnancy: Incontinence measured as early as 3 months and as late as 4 years after birth.
    Added likelihood for a woman who does kegel exercises regularly during pregnancy: VERY HIGH for being continent by 3 months after birth
  • prevent, improve or cure urinary incontinence if done after birth
    Added likelihood for an incontinent woman who does kegel exercises regularly after birth: HIGH for improvement or cure

Is using weighted vaginal cones or electrical stimulation better than kegel exercises for improving or curing urinary stress incontinence?

Using vaginal cones involves inserting a small cone-shaped weight into the vagina and holding it there against gravity. As pelvic floor muscle strength improves, heavier cones are used. With electrical stimulation, a small vaginal or anal probe passes a low electric current to stimulate the muscles around the bladder to contract.

Neither the use of vaginal cones nor electrical stimulation appears to produce better results compared with a program of kegel exercises. In addition, studies comparing pelvic floor exercises with vaginal cones or with electrical stimulation reported occasional adverse effects with these other techniques but not with pelvic floor exercises.

Does combining kegel exercises with vaginal cones, electrical stimulation, or biofeedback do better at improving or curing urinary stress incontinence than a program of kegel exercises alone?

Using vaginal cones involves inserting a small cone-shaped weight into the vagina and holding it there against gravity. As pelvic floor muscle strength improves, heavier cones are used. With electrical stimulation, a small vaginal or anal probe passes a low electric current to stimulate the muscles around the bladder to contract. Biofeedback uses special equipment to give visual feedback on which muscles are being contracted so that the woman can learn to do pelvic floor contractions correctly.

We lack good research in this area, but what research we have does not show any advantage to combining these techniques with a program of kegel exercises, in comparison with kegel exercises alone.

What is the benefit of a routine of perineal massage in the final weeks of pregnancy?

A small body of research found that, although many women and their partners found it challenging to maintain a routine every day or most days per week, perineal massage in the final weeks of pregnancy appears to help:

  • prevent trauma to the perineum, defined as episiotomy and spontaneous tears combined, and promote birth with an intact perineum in first-time mothers (evidence of effectiveness in subsequent pregnancies unclear at this time) Added likelihood for a first-time mother: VERY HIGH to HIGH for avoiding perineal trauma and giving birth with an intact perineum.



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Childbirth Connecction. Comparing risks of cesarean and vaginal birth to mothers, babies, and future reproductive capacity: a systematic review. New York: Childbirth Connecction, April 2004. [The following study documents are available as PDF files from the Childbirth Connecction website: description of methods and sources (including full bibiliography), list of main questions and outcomes (a table of contents for evidence tables), first file of evidence tables, and second file of evidence tables. Latter includes pelvic floor outcomes.]

McGuiness M, Norr K, Nacion K. Comparison between different perineal outcomes on tissue healing. J Nurse Midwifery 1991;36(3):192-8.

Renfrew MJ, Hannah W, Albers L, Floyd E. Practices that minimize trauma to the genital tract in childbirth: a systematic review of the literature. Birth 1998;25(3):143-60.

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Vendittelli F, Tabaste J-L, Janky E. Le massage prinal ante-partum: revue des essais randomiss. J Gynecol Obstet Biol Reprod 2001;30(6):565-71.

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Tips & Tools: Pelvic Floor Dysfunction


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Childbirth Connection is a national not-for-profit organization founded in 1918 as Maternity Center Association. Our mission is to improve the quality of maternity care through research, education, advocacy and policy. Childbirth Connection promotes safe, effective and satisfying evidence-based maternity care and is a voice for the needs and interests of childbearing families.
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