In short
- Diastasis is the separation of the two rectus muscles, with the linea alba between them stretched. It is a problem of the muscular plane.
- The caesarean shelf is above that, between the fat and the fascia, and has nothing to do with the recti. You can have both, and that is the commonest case.
- 🔑 The caesarean appears as a risk factor for diastasis, with an odds ratio of 3.48 in the cohort that measured it.
- Diastasis improves on its own in a considerable proportion of cases during the first year. The shelf does not.
- ⚠️ The evidence on exercise for treating diastasis is of very low quality, according to a systematic review of seven trials. That does not mean it is no use: it means no particular programme can be recommended over another.
- And one that surprises people: in that same cohort, diastasis was not associated with urinary incontinence or prolapse, not even with wider separations.
- That is why the sensible order is to wait, work the abdominal wall and assess afterwards, with the information of what has improved and what has stayed.
The caesarean is associated with more diastasis of the recti: in a cohort of 229 women, it multiplied the probability of having it during the first postpartum year by 3.5. But diastasis and the shelf at the scar are two different problems, in different layers of the same wall, and that distinction is what decides what improves with time, what improves with exercise and what improves with neither.
This page deals only with that relationship: what the caesarean has to do with diastasis, how one is told from the other and what to expect from each treatment. The full approach to diastasis as a problem in its own right has its own page.
This page sets out one of the boundaries raised by the caesarean sequelae as a whole.
What each one is, and why they get confused
The two rectus abdominis muscles run from the ribs to the pubis, one on each side, joined by a central fibrous band called the linea alba. During pregnancy that band stretches to make room, and the recti separate. That is diastasis: it is not that the muscle is weak or torn, it is that the central join is wider.
The caesarean shelf happens somewhere else. It is between the skin and the muscle: Scarpa’s fascia left unclosed, its edges retracting, the deep fat herniating into the superficial plane and the scar left anchored (Pelosi, 2026). The muscle can be perfectly fine and the shelf still be there.
They get confused because they produce the same visible effect: an abdomen that sticks out and does not respond to what you would expect. But the remedy is not the same, and that is the whole use of telling them apart.
| Diastasis | Shelf or “apron” | |
|---|---|---|
| Where | Muscular plane: the linea alba between the recti | Between the fat and the fascia, above the muscle |
| How it shows | A central bulge on sitting up; a groove can be felt between the recti | A roll over the scar, with a depressed groove in the middle |
| Does it improve on its own? | In a good proportion of cases, during the first year | No |
| Does it improve with exercise? | It may, although the evidence is of very low quality | No |
| What corrects it otherwise | Plication of the recti, within an abdominoplasty | Removing the excess and releasing the scar |
What the caesarean has to do with diastasis
The caesarean appears as an independent risk factor. In a retrospective cohort of 229 women studied during the first postpartum year, the caesarean was associated with diastasis with an odds ratio of 3.48 (95% CI 1.42-8.56), and multiple births with one of 3.20 (Fei, 2021).
⚠️ On prevalence something uncomfortable has to be said: it depends where the bar is set. In that cohort it was 82.6% during the first year, with a criterion of separation ≥20 mm measured at three points. In a Norwegian cohort of 300 first-time mothers, with a different criterion, it was 60.0% at six weeks, 45.4% at six months and 32.6% at a year (Sperstad, 2016).
🔑 They do not contradict each other: they are not measuring the same thing. And both agree on what is useful to the reader: it is very common, and a considerable proportion resolves on its own during the first year.
What improves on its own, and what does not
This is the practical part.
Diastasis improves on its own in a considerable proportion of cases. The Norwegian cohort, which followed the same women through the year, documents the fall: 60.0% → 45.4% → 32.6%. That is, rather less than half of those who had it at six weeks no longer had it at a year.
The shelf does not behave like that. The herniated fat does not return to its plane and the anchored scar does not release with time. Anyone with both problems notices exactly that: the abdomen improves for months and then stops halfway.
⚠️ And here is the real cause of a lot of frustration: the improvement of the first few months creates the expectation that the rest will go too. It is not that the effort has been wasted; it is that it was acting on one of the two problems.
Exercise: what can honestly be said
It is the first thing recommended everywhere, and it deserves a precise answer.
A systematic review with meta-analysis of seven randomised trials and 381 women assessed whether abdominal and pelvic floor exercise programmes treat postpartum diastasis. Its conclusion, verbatim: “there is currently very low quality scientific evidence to recommend specific exercise programmes in the treatment of postpartum diastasis” (Gluppe, 2021). Transversus training reduced the inter-recti distance by a mean of 0.63 cm, with very low quality evidence; pelvic floor work was not shown to be superior to minimal intervention.
🔑 What that means, and what it does not. It does not mean exercise is useless or should be stopped: working the abdominal wall has benefits that go well beyond the distance between the recti. It means there is no basis for promising that a particular programme will close a diastasis, or for selling one over another.
⚠️ And one finding from the same body of studies worth knowing, because the opposite circulates widely: in the cohort of 229 women, diastasis was not associated with urinary incontinence or prolapse, not even when the separation threshold was raised (Fei, 2021). It is a fact that lowers the level of alarm with which it is sometimes presented.
When diastasis becomes part of an operation
When it persists and causes symptoms or a bulge that does not settle, the surgical correction consists of bringing the recti together — the plication — and is done within an abdominoplasty, not as a stand-alone operation.
And this is where the two problems meet again: how far the diastasis extends is the variable that decides which operation applies in caesarean sequelae. If it is only below the navel, the step is the mini tummy tuck; if it also reaches above, the full abdominoplasty. It is set out in how the surgery is decided.
⏱️ The interval worked to here is from six months after the caesarean, and the figures above explain why: before that point, part of what you see is still resolving. It is set out in when to have surgery after a caesarean.
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Frequently asked questions
Does a caesarean cause diastasis?
It is associated with it: in the cohort that measured it, it multiplied the probability of having it during the first postpartum year by 3.48. Diastasis is produced above all by the stretching of pregnancy, so the caesarean is an added factor and not the sole cause.
How do I know whether I have diastasis or the scar shelf?
Diastasis shows as a central bulge when you sit up from lying down, and a groove can be felt between the two muscles. The shelf is a roll over the scar, with the line depressed in the middle. Many women have both, which is why they are worth examining together.
Does it close on its own?
In a considerable proportion of cases, yes, during the first year: in the Norwegian cohort it went from 60.0% at six weeks to 32.6% at twelve months. That is the main reason for not deciding anything before that point.
Do hypopressive exercises or transversus work close it?
The available systematic review concludes that the evidence is of very low quality for recommending any particular programme. That does not mean the abdominal wall should not be worked, but that it cannot be promised that a given method will close it.
Does diastasis cause incontinence or prolapse?
It is what tends to be taken for granted, and the cohort that studied it found no such association, not even with wider separations. Pelvic floor problems have causes of their own and are assessed separately.
If I have surgery for the shelf, will the diastasis be fixed too?
Where it is indicated, yes: plication of the recti is part of the abdominoplasty and of the mini tummy tuck. How far the separation extends is precisely what decides which of the two applies.
Can I do ordinary sit-ups if I have diastasis?
That is a question for whoever is handling your recovery, because it depends on the separation and on the stage. What can be said is that the available evidence does not support any particular exercise being clearly better than another at closing it.
Sources
- Fei H, Liu Y, Li M, He J, Liu L, Li J, Wan Y, Li T. The relationship of severity in diastasis recti abdominis and pelvic floor dysfunction: a retrospective cohort study. BMC Women’s Health. 2021;21(1):68. PMID 33588826 — Retrospective cohort of 229 women during the first postpartum year, with diastasis defined as separation ≥20 mm. Prevalence of 82.6%. Caesarean was a risk factor (OR 3.48; 95% CI 1.42-8.56) and so were multiple births (OR 3.20). It found no association between diastasis and urinary incontinence or prolapse, at any threshold. Verified on 29-08-2026.
- Sperstad JB, Tennfjord MK, Hilde G, Ellström-Engh M, Bø K. Diastasis recti abdominis during pregnancy and 12 months after childbirth: prevalence, risk factors and report of lumbopelvic pain. British Journal of Sports Medicine. 2016;50(17):1092-1096. PMID 27324871 — Prospective cohort of 300 first-time mothers: 33.1% at week 21 of pregnancy, 60.0% at 6 weeks after delivery, 45.4% at 6 months and 32.6% at a year. It is the source for the change over time, and its different criterion from the previous study explains the difference in prevalence. Verified on 29-08-2026.
- Gluppe S, Engh ME, Bø K. What is the evidence for abdominal and pelvic floor muscle training to treat diastasis recti abdominis postpartum? A systematic review with meta-analysis. Brazilian Journal of Physical Therapy. 2021;25(6):664-675. PMID 34391661 — Seven randomised trials and 381 women. Transversus training reduced the inter-recti distance (−0.63 cm; 95% CI −1.25 to −0.01) with very low quality evidence. Conclusion: there is no basis of sufficient quality for recommending specific exercise programmes in the treatment of postpartum diastasis. Verified on 29-08-2026.
- Pelosi MA 2nd, Pelosi MA 3rd, Romero R. The cesarean apron: description, proposed pathophysiology, classification, and prevention through Scarpa fascia closure at cesarean delivery. American Journal of Obstetrics and Gynecology. 2026;233(6S):S118-S128. PMID 41485815 — It supplies the mechanism of the shelf, which occurs above the muscular plane, and its four-grade classification, in which the extent of the diastasis is what separates grade 3 from grade 4. It is what connects the two problems in the surgical decision. Verified on 29-08-2026.
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If you have worked your abdomen for months and notice that it has improved up to a point and stopped there, what clarifies the situation is an examination: how much separation is left, where it is and whether there is also a shelf above it. With that you know what is left to improve and what is not going to improve on its own.
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Last reviewed: 6 September 2026. This content is for information only and does not replace an individual assessment by a healthcare professional.
