Pelvic floor injury during vaginal birth is life-altering and preventable, experts say

Nearly one in 10 women who give birth vaginally every year eventually require surgery because of  a pelvic floor disorder.

Vaginal childbirth has particularly been linked with risks for prolapse of the pelvic organs, when the muscles and tissues supporting the uterus, bladder, or rectum fail, causing discomfort and incontinence.

But there are effective ways to prevent and treat these conditions, experts say, describing such interventions in a Michigan Medicine-led review in the American Journal of Obstetrics and Gynecology.

Among key goals is better educating people about individual labor risks and options ahead of giving birth, says lead author John De Lancey, M.D., a urogynecology specialist at U-M Health Von Voigtlander Women’s Hospital.

“We know that women can experience distressing lifelong consequences due to the pelvic floor’s unique role in childbirth. Until recently, however, we did not know exactly what happened during vaginal delivery that led to these problems,” said De Lancey, who is also director of the Pelvic Floor Research Group at Michigan Medicine.

“Our research has demonstrated the types of pelvic floor injuries that occur and also what causes them. This provides obstetricians and midwives with critical information about how these injuries and their subsequent problems can be prevented.”

De Lancey answers more questions about pelvic floor injuries and childbirth:

How is childbirth related to pelvic floor problems?

De Lancey: Pelvic floor diseases can be caused by different factors but some, such as prolapse, are most strongly associated with vaginal birth. This is especially true for births that involve bigger babies, older moms and forceps delivery.  

During birth, the levator muscle – the muscle that holds the organs in place – and birth canal tissues must stretch to more than three times their original length. In some cases, this stretch can cause muscle tears and connective tissue damage that lead to pelvic floor problems later in life.

Our research suggests that pelvic organ prolapse may develop after the levator is torn from the pubic bone during vaginal birth. 

How can delivering individuals reduce risk of injury?

De Lancey: There are several different injuries that occur during childbirth that mainly affect the muscles and connective tissues that surround the lower birth canal. 

We are now able to diagnose these injuries in the pelvic floor using ultrasound and MRI, providing essential insights for developing prevention strategies and best practices in rehabilitation.  Before the injury was discovered, studies could not be done about prolapse risk because it didn’t occur until some years after birth. Now that the injury is known, it can be evaluated soon after birth using ultrasound.

Armed with this knowledge, there are several steps we can take to reduce risk of injury. Clinicians, for example, can use vacuum rather than forceps when assistance is needed.  A baby whose head is turned the wrong way can be rotated to the normal position before birth. Induction of labor at 39 weeks, as is commonly performed, may help as well.

Women may also be coached to relax their pelvic floor muscles during pushing — not only to speed delivery by the muscles being more stretchy but also to minimize the risk of damage to the muscles.

Additionally, strategies are being developed to pre-stretch the birth canal gradually during labor to lessen the likelihood of its injury. These are already in clinical trials. We need to do more work to develop tests that identify specific women at unusually high risk for injury so that they can discuss these options with their doctor or midwife and consider caesarian delivery. 

Why is prenatal education about pelvic floor disorders key?

De Lancey: Studies show a lack of knowledge among pregnant women about pelvic floor conditions. Many are also reluctant or embarrassed to talk to their doctor or believe their symptoms are normal so the scope of the problem is hidden.

Prevention should be discussed with every pregnant woman as part of routine care so that injured women no longer have to say “Why didn’t anyone tell me this might happen?”

Better information is needed for expectant patients on their risk of pelvic floor injuries and the implications of these injuries on lifetime pelvic floor function. This education empowers them to make informed decisions about management options during labor.   

Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery.   

What innovations are helping advance research to improve outcomes?

De Lancey: Twenty years ago, all of this was a mystery and there was no rational basis for injury prevention or recovery. 

Our gynecology and nursing team at U-M Health, along with biomechanical engineers from the U-M School of Engineering, have spent two decades carefully researching new MRI technology and using 3-D biomechanical engineering analyses to learn more about the mechanisms underlying these injuries.

James Ashton-Miller in the College of Engineering has led the biomechanical engineers in our group while drawing on his rich experience with the mechanisms of injuries that occur, for example, during sports or falls in the elderly.

Janis Miller in the U-M School of Nursing has conducted important research identifying the specific nature of the injury, and factors that cause it, along with many studies on the causes of incontinence. She has focused on simple clinician measures to screen for injury. Women typically find the information reassuring. If a major change indicating injury is noted, there is opportunity for the clinician to focus on strategies to prevent, delay or reduce related symptoms. 

Our close collaborations have led to developing a 3D stress MRI to evaluate each individual woman's risk of prolapse to find the best ways to prevent it. The 3-D computer modeling simulates birth on a computer, examining how the levator ani muscle, or Kegel muscle, is affected by several factors, such as the shape of the muscle, where it attaches, variations in the birth canal and the size of the fetal head in relation to the birth canal.

The remarkable changes in the birth canal needed to allow a baby to emerge from the mother’s body have now been clarified, for example, and we can better understand variations from one woman to the next. 

This helps us predict how likely it is for the delivering person to experience injury during childbirth so they can consider this risk in their birth plan.

Are these conditions completely preventable and treatable?

De Lancey: While we can’t eliminate these conditions completely, it is possible to reduce the chance a woman suffers from pelvic floor injury. 

We know that women can experience distressing lifelong consequences due to the pelvic floor’s unique role in childbirth.”  John De Lancey, M.D.

Help for people recovering from birth is essential to fulfill our responsibility to aid the injured. Postpartum perineal clinics, such as the Healthy Healing After Delivery clinic at U-M Health, have emerged to fill the gap between hospital discharge and initial obstetrical follow-up.

These collaborative multidisciplinary care centers, which include urogynecologists, nurses, physical therapists, and other advanced practitioners, provide early individualized assessment, education, and intervention for pelvic floor symptoms in pregnant and postpartum women.

Women are seen from as early as one week and up to one year after delivery. Postpartum clinics provide an opportunity for early pelvic floor and mental health screening, intervention, and prevention of long-term health issues. 

Why are pelvic floor injuries an important focus in the field of obstetrics and gynecology?

De Lancey: Pelvic floor disorders after childbirth have devastating consequences on quality of life.  

Symptoms may include the protrusion of organs from the vaginal opening from prolapse, leaking urine when laughing, coughing, or exercising, leaking feces and impaired sexual function.  

One in four American women suffer from these conditions and 20% of women will require surgery during their lifetime while others experience nonsurgical conditions, such as urgency urinary incontinence. 

Birth injury affects almost three times the number of people sustaining common knee sprains or tears in the anterior cruciate ligament, or ACL. While physical therapy is part of the standard of care management for an ACL injury, far fewer women are receiving care for injuries resulting from birth.

These are injuries that, when left untreated, can lead to short and long term disabilities. We need to combine expertise across specialties to better analyze everyone’s risk of injuries, counsel patients before birth to consider different delivery options as well as assist with pain management, functional restoration and disability prevention in this patient population. 

Additional authors: Mariana Masteling, Ph.D.; Fernanda Pipitone, M.D.; Jennifer LaCross, D.P.T., Ph.D.; Sara Mastrovito M.D., and James Ashton-Miller Ph.D.

Citation: “Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it?” DOI: 10.1016/j.ajog.2023.11.1253

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