Diastasis Recti and Pregnancy: ‘Closing the gap’ between current treatment practices and clinical evidence

[kkstarratings]

Diastasis recti (also known as “rectus diastasis”) is a common result of pregnancy, and a lot of online advice is available to help treat it – both good and questionable. Thankfully clinical research is starting to catch up, and can help us identify the best evidence-based treatment approaches. Here we review what the latest research says.

What is diastasis recti?

It is common and normal to have some separation between your rectus abdominus abdominal muscles (which you may refer to as your ‘6-pack’). In women that have not given birth, 1 cm (or one finger) separation at the level of the belly button and 0.5 cm above and below, is normal.

Some separation of the rectus abdominus muscles occurs naturally during pregnancy as the uterus grows and hormonal changes relax connective tissue, and this separation also naturally recovers postpartum. This recovery occurs between the first day and 8 weeks after birth, and then plateaus (ref1). Following pregnancy, it is normal for the separation to be as large as 1.5 to 2 cm at the belly button level (ref2).

More than 50% of women have pathological levels of diastasis recti immediately following delivery (ref3), and for many of these women post-partum recovery of the separation is incomplete. A space of more than 2.7cm at the level of the belly button is typically considered to be pathological (ref4).

Most women with a rectus diastasis will notice a bulge between their abdominal muscles when they try to do sit ups or lift their child. With contraction of their abdominals they may also be able to feel a separation between the muscles at their midline of more than two finger-widths.

But is this extra space between the two sides of your abdominals really a problem?

Is diastasis recti problematic?

Since we all have some separation between our abdominals already, what is the significance of having a wider gap? Surprisingly, clinical research has lagged in this area, but is starting to accumulate.

The key problem caused by diastasis recti appears to be that the separation in your abdominal muscles decreases functional abdominal strength (and likely in turn causes muscle imbalance and loss of coordination). A paper published recently identified a correlation between muscle weakness and the size of the gap below (but not above) the belly button; the larger the gap, the weaker the muscles (ref5).

Interestingly, new research is accumulating that suggests that the depth of the gap between the muscles  may be a better indicator of an abdominal functional deficiency than the width of the gap. A deeper gap would reduce the ability of the connective tissue in the gap (the linea alba) to work with the muscles to create tension across the abdomen. For this reason, pelvic floor physiotherapists will assess both the width of the gap and the depth during an evaluation.

Weakened abdominals diminish overall abdominal integrity and can lead to other related problems such as low back pain, pelvic girdle pain, and pelvic instability (ref6, ref7). This is not surprising since the pelvic floor muscles work in concert with the abdominal muscles to allow load to be transferred effectively through the pelvis. When this fails to function properly, women with diastasis recti may experience pelvic floor related problems such as incontinence or prolapse (ref8).

The presence of diastasis recti is also an indicator that you may not be ready to safely return to postpartum exercise (see “5 Signs You’re Not Ready for Postpartum Exercise“)

Can exercise treat diastasis recti?

Diastasis recti is conventionally treated through targeted exercise therapy, specifically abdominal exercise. Clinical studies are still few and small (and therefore too statistically weak to be conclusive), but exercise does show promise for both preventing and reducing diastasis recti (ref2). This supports what I and other pelvic floor physiotherapists are taught, and also see in clinical practice.

The general rationale behind abdominal exercise is that it can generate a horizontal force that will act to close the abdominal gap. Two new studies of diastasis recti show that certain muscle contractions can act to bring the abdominals closer together, giving support to the notion that strengthening one’s abdominal muscles will act to hold the sides together during rest as well (ref9, ref10). But the type of exercise matters, as some abdominal exercises may actually pull the sides further apart (ref9).  Further studies are needed to tease out these specifics and we will be following this research closely.

It’s important to also note that no exercise is inherently ‘bad’ during or following pregnancy. Whatever exercise an individual chooses to do, the important thing is to ensure that they are able to create good tension across the abdomen and effectively control the intra-abdominal pressure that is generated (ie no abdominal ‘doming’ or ‘coning’). This is one area where the advice of a pelvic floor physiotherapist can be beneficial. For example, a pelvic floor physiotherapist can find creative and individualized ways to cue patients to turn on inner core muscles during exercise – actions that are necessary for proper pressure control, and that were likely occurring automatically prior to pregnancy.

What should exercise therapy involve?

The treatment approach depends on your condition, and in particular, the extent of abdominal separation.

For separations that are smaller than 4 finger widths, corrective exercise is the best first line approach in order to help draw the two bellies of the rectus abdominus together. Exercise is typically done for 2 to 6 weeks until the separation is closed or less than 2 finger widths.

It is important that corrective exercise include strengthening of the muscles of your inner core, your support muscles. The inner core is made up of the diaphragm (main breathing muscle), multifidus (a deep back muscle), transversus abdominus (the body’s equivalent to a corset), and the pelvic floor muscles.

Transversus abdominis muscle strengthening may be the most beneficial therapeutic target, and has been the focus of most clinical studies to date (ref10).

The transversus abdominus muscle has been shown to have strong fascial connections to the rectus abdominus. Strengthening of this muscle can therefore help draw the two rectus abdominus muscle bellies together and increase fascial tension (ref8). This allows load to be transferred effectively though the pelvis during lifting or exercise. There are different ways that strengthening of the transversus abdominus can be achieved, and no standardization exists to date in the clinical literature.

Physiotherapy for diastasis recti should consider more than just the separation. Retraining of the pelvic floor muscles is another important area of treatment that is often unaddressed. More than 70% of women cannot create a pelvic floor contraction in the presence of a rectus diastasis, and as a result are more likely to experience incontinence, prolapse and pelvic pain (ref11). It is also important to look at posture, body mechanics and restricted tissues or joints that may be driving poor movement patterns. Seeking the guidance of a physiotherapist, in particular one with training in pelvic floor physiotherapy, can be beneficial.

For larger separations that are 4 finger widths or more, a corset or binder is typically recommended in conjuction with exercise. This is typically worn 24 hours of the day and taken off for bathing and exercises. Surgery, called abdominoplasty, may be considered for some women who have exhausted exercise therapy options, and who meet a range of additional criteria. Surgery may provide relief for some symptoms including low back pain (ref12), but may primarily offer aesthetic benefit.

How should I proceed?

It is safest and most effective to seek out the advice of a health care practitioner trained to treat diastasis recti, such as a Physiotherapist trained in Pelvic Floor Physiotherapy. Incorrect exercises or exercises incorrectly performed can be ineffective, or at worst, counterproductive and harmful. Your therapist should be able to create a targeted home exercise therapy program customized to your needs, and safely guide you through your rehabilitation.

References

1. Coldron Y., Stokes M., Newham D., et al. Postpartum characteristics of rectus abdominis on ultrasound imaging. Man Ther. 2008; 13:112-121. https://doi.org/10.1016/j.math.2006.10.001
2. Benjamin D.R., van de Water A.T., Peiris C.L. Effects of exercise on diastasis of the rectus abdominis muscle in the antenatal and postnatal periods: a systematic review. Physiotherapy. 2014 Mar;100(1):1-8. https://doi.org/10.1016/j.physio.2013.08.005
3. Boissonnault J.S., Blaschak M.J. Incidence of diastasis recti abdominis during the childbearing year. Physical Therapy. 1988; 68:1082-1086 abstract
4. Rath A.M., Attali P., Dumas J.L., et al. The abdominal linea alba: an anatomo-radiologic and biomechanical study. Surg Radiol Anat. 1996;18:281-288. abstract
5. Gunnarsson U., Stark B., Dahlstrand U., et al. Correlation between abdominal rectus diastasis width and abdominal muscle strength. Dig Surg. 2015;32(2):112-6.  https://doi.org/10.1159/000371859
6. Lo T., Candido G., Janssen P. Diastasis of the recti abdominis in pregnancy: risk factors and treatment. Physiother Can. 1999;44:32-37.
7. Gilleard W.L., Brown J.M. Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period. Phys Ther. 1996;76:750-62. abstract
8. Lee D.G., Lee L.J., McLaughlin L. Stability, continence and breathing: the role of fascia following pregnancy and delivery. J Bodywork Move Ther. 2008;12:333-48.  https://doi.org/10.1016/j.jbmt.2008.05.003
9. Mota P., Pascoal A.G., Carita A.I., et al. The immediate effects of inter-rectus distance of abdominal crunch and drawing-in exercises during pregnancy and the postpartum period. J Orthop Sports Phys Ther. 2015 Oct;45(10):781-8. abstract
10. Pascoal A.G., Dionisio S., Cordeiro F., et al. Inter-rectus distance in postpartum women can be reduced by isometric contraction of the abdominal muscules: a preliminary case-control study. Physiotherapy. 2014 Dec;100(4)344-8.  https://doi.org/10.1016/j.physio.2013.11.006
11. Spitznagle T.M., Leong F.C., Van Dillen L.R. Prevalence of diastasis recti abdominis in a urogynecological patient population. Int Urogynecology J Pelvic Floor Dysfunct. 2007 Mar;18(3):321-8. abstract
12. Taranto I. The relief of low back pain with WARP adominoplasty: a preliminary report. Plastic Reconstruct Surg. 1990; 85:545-555. abstract

Acknowledgements

This article was a collaboration between Katie Hauck, PT and Ryan Davey, PhD.