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Pelvic Floor Therapy for Birth Prep: Can Perineal Tears Be Prevented With Biofeedback?

It breaks my heart when I see a new patient postpartum who has sustained a severe perineal tear or other birth trauma. I always wonder, if she would have come for birth prep pelvic floor therapy could the injury have been prevented?

What Causes Birth Trauma?

We know some factors increase a woman's risk of sustaining a vaginal or perineal tear (Jansson et al., 2020) ( such as:

Vacuum assisted birth/ Instrument Assisted Birth: While never part of the birth plan, in a situation where baby or mom is in distress and the birth needs to happen quickly, a vacuum or forceps may be used. In such a situation there is a higher risk to mom of OASI (Obstetric Anal Sphincter Injury) or a Grade 4 perineal tear.

Larger fetal size: Babies weighing over 4,000 g (about 8.8 lbs) and/or fetal head circumference over 35 cm (about 13.8 inches) increase mom's risk of sustaining a birth injury.

Post-term delivery: The longer the baby stays inside mom the larger the baby grows before birth and the more likely baby is to reach over 4,000 g with a larger head circumference.

Longer second phase of labor: The second phase of labor is the pushing phase. More pushing is associated with more injury.

Heredity of pelvic floor dysfunction and/or connective tissue deficiency: Do you have a mother or sister with pelvic organ prolapse, urinary incontinence, inguinal hernia, hypermobility or varicose veins? If so you may be genetically predisposed to an increased risk of trauma with childbirth. While heredity is not destiny, women with pelvic floor dysfunction often have pelvic floor muscles that are overly tight and do not want to lengthen or open up during birth to allow baby to easily pass through. The thought is that these tight muscles are more prone to tearing during childbirth. Connective tissue deficiency or hypermobility results in tendons and ligaments that have more stretch and give. If you can do the splits or can bend your thumb backwards to touch your wrist then you may be hypermobile. The belief is that a prolonged second labor phase and pushing against hypermobile tissue can contribute to birth injury and prolapse for mom.

What Reduces the Risk of Birth Trauma?

Sadly there is much less research to answer this important question. We do know that there is some evidence (Jansson et al., 2020) ( to support the use of:

Warm compresses during birth: You may have heard that physically supporting the perineum can help reduce the risk or severity of tears. Theres not great evidence for this practice but there is better evidence for the use of warm compress on the perineum.

Perineal massage: With physician approval, gentle stretching of the perineal tissue (for a few minutes a few times a week beginning at 35 weeks of pregnancy) has been shown to reduce the risk of tears for first time birthing moms. I always teach this technique in my Birth Prep sessions.

Birthing positions that allow for SI joint mobility: The worst birthing position is thought to be lying on your back with your SI joint and coccyx pressed flat against the bed/table. Positions such as sidelying or supported squat that allow the sacrum and coccyx to freely move and extend to allow more space in the pelvis for the baby to move through are better. If a mom wants or needs to birth on her back I highly encourage the use of a coccyx-cut-out-cushion (or rolled up towel elevating the pelvis) to give the SI joint and coccyx room to extend as they need to during birth.

Pelvic Floor Therapy Can Help So Much More

So are we to believe then that our greatest opportunity to avoid physical birth trauma is to hold a warm compress on our perineum and hope to birth a baby with a small head circumference?!? I reject this idea outright. There is so much we can do to protect our bodies and have the birth we want.

I work with pregnant women daily and help them to learn the birthing techniques that will reduce their risk of tears and put them in an optimal position through the second phase of labor. This is especially important for women who have pre-existing pelvic floor muscle dysfunction. The primary tool I use to support women in achieving these outcomes is pelvic floor biofeedback.

Biofeedback for Birth Prep

Biofeedback uses small sensors with stickers that attach to the pelvic floor and abdominal muscles. The muscle movements are then transmitted from the sensors through an amplifier device onto a computer screen and visually presented for the user to better understand how she is using her muscles correctly, or incorrectly in some cases, for labor and birth.

During the second phase of labor, the objective is to keep the pelvic floor muscles lengthened, even "bulge" them a bit to allow for as least resistance as possible during the birth. Contracting the abdominal muscles can assist the uterus to bring baby through the pelvis. However, since the pelvic floor muscles actually prefer to contract with the abdominal muscles, rather than lengthen, it can take some practice to master this new skill.

In the image above, the abdominal muscle movements (contractions) are seen in blue and the pelvic floor muscle movements are shown in green. This mom-to-be is working on trying to get her pelvic floor muscles to lengthen rather than contract with her abdominal muscles. We can see she's not quite there yet, but she did master the skill and went on to have a healthy baby girl and no perineal injury.

In the photo above mom-to-be is facing a mirror and looking at a mirror image of the computer while using biofeedback. On the computer screen, you can see she is doing a fantastic job of engaging her abdominal muscles (in blue) at a higher level than her pelvic floor muscles (green). And yes she has a balloon placed on her perineum! It's a great tactile tool so she can actually feel her pelvic floor muscles as they lengthen.

In my Birth Prep sessions we work in a variety of labor and birthing positions to determine the optimal positions where a woman can get that desired pelvic floor muscle lengthening. One woman may be able to optimally lengthen on hands and knees, while for another woman sidelying or supported seated may be better. Everyone is different and what I love about biofeedback is it provides quantitative data so mom can be confident and prepared knowing what positions are optimal for her.

I firmly believe that all women can learn these techniques to optimize their second stage of labor and improve their birthing outcomes. I'm especially passionate that pelvic floor birth prep with biofeedback should be made available to all women who had issues of pelvic floor dysfunction prior to their pregnancy such as incontinence, prolapse, constipation, pelvic pain and hypermobility. In this day and age there is no reason obstetric injuries should happen. I believe biofeedback can be a vital tool for prevention.

Carol Harmon OTR/L, MOT, M.Ed., LPF-CT, HSP is a Pelvic Floor Occupational Therapist and owner of Core Functional Wellness (CFW) in San Diego, CA. CFW offers Pelvic Health Occupational Therapy & Biofeedback for incontinence, overactive bladder, recurrent UTI, constipation, IBS, IC, prolapse, pain, diastasis, trauma and anxiety. Carol offers Birth Prep and wellness services as well. You can find out more or schedule an appointment at

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