Diastasis recti after birth: what helps and what the evidence says

If you have noticed a soft ridge or a dip down the middle of your tummy since giving birth, you are in very good company. Diastasis recti is one of the most common changes after pregnancy, and also one of the most misunderstood. This guide explains what it is, how to check for it, which kind of core work makes sense, and what the research honestly does and doesn't show.

What is diastasis recti?

Your rectus abdominis has a left and a right side, joined down the middle by a band of connective tissue called the linea alba. During pregnancy, that band stretches and thins so your abdomen can expand. After birth, the gap between the two sides may stay wider for a while, and the midline can feel soft or dip in when you lift your head.

Researchers usually describe diastasis recti as a separation of two or more finger widths, measured at the belly button or a few centimetres above or below it.^[1] Width is only part of the picture, though. How the tissue between the muscles behaves when you use your core seems to matter too, which is why physiotherapists look at tension and control as well as the size of the gap.^[7]

How common is diastasis recti after birth?

The clearest picture comes from a study that followed 300 women through their first pregnancy and the year after birth.^[1]

Most of these separations were mild. The study found no difference in lower back or pelvic pain between women with and without diastasis recti. Women who reported heavy lifting at least 20 times a week were more likely to have it, though a study like this can't show that lifting caused it.^[1]

A later systematic review of twelve studies found no significant link between diastasis recti and lumbo-pelvic pain or incontinence, a small link with pelvic organ prolapse, and some weak evidence that a wider gap goes with weaker abdominal muscles, more severe back pain and lower quality of life.^[2] In other words, a gap on its own isn't a problem to fear. How you feel and how your body works matters more than a number.

How can I check for diastasis recti?

A simple self-check, step by step:

1. Lie on your back with your knees bent and feet flat on the floor.
2. Place the fingertips of one hand across the midline of your tummy, at your belly button.
3. Breathe out and lift your head and shoulders just slightly off the floor.
4. Notice how many fingers fit into the gap between the two muscle edges, and whether your fingers sink in deeply or meet firmer tension.
5. Repeat a few centimetres above and below your belly button.

Two or more finger widths matches the definition many studies use.^[1] Notice depth and firmness as well: a narrower gap that feels very soft and deep can tell you more than a wider one that feels firm. Our diastasis recti self-check guide walks you through each step and explains what the results usually mean. A pelvic health or musculoskeletal physiotherapist can assess you properly if you're unsure.

What core exercises help with diastasis recti?

Here is the honest part. Exercise for diastasis recti has been studied, but not well. A 2014 systematic review found that the available studies were of poor quality and concluded that non-specific exercise may or may not help prevent or reduce it.^[3] A randomised trial in which women joined a weekly supervised class with pelvic floor and abdominal training from six weeks after birth found no difference in how many had diastasis recti at six or twelve months, compared with women who didn't take part.^[4] A 2021 review with meta-analysis concluded that there is currently very low-quality evidence to recommend any specific exercise programme for diastasis recti after birth.^[5]

That doesn't mean core work is pointless. It means its value lies in how you feel and function: managing pressure, lifting your baby, returning to the activities you love. The return-to-running guideline puts it simply: a diastasis can be functional when you have strategies to control the pressure in your abdomen and transfer load across your abdominal wall.^[9]

A gentle progression that follows our postpartum stages:

• Weeks 0–6. Slow breathing into your ribs, pelvic floor squeezes, and gently drawing your lower tummy in as you breathe out. Short walks. The box breathing timer is a calm place to start.
• Weeks 6–12. Bridges, side-lying leg lifts, hands-and-knees exercises such as reaching one arm or leg at a time, and moderate strength work with bands or light weights. Exhale on the effort.
• From 12 weeks. Gradually heavier lifting, carrying and rotation, and, once you have had no pelvic floor symptoms for two weeks, more demanding abdominal work.

Throughout, watch your midline. If it domes or ridges up as you move, the exercise is probably asking more than your body can manage right now, so choose an easier version. The guideline describes doming or sinking at the midline as a sign that load isn't being transferred well yet.^[9]

Are crunches bad for diastasis recti?

For years, women were told never to do a crunch with diastasis recti. The research is more nuanced. When a study measured the gap with ultrasound in 84 first-time mothers, a crunch narrowed it at every point measured during and after pregnancy, except one point below the belly button at six months. The drawing-in exercise, by contrast, generally widened it slightly after birth.^[6]

So is narrowing the gap the goal? Not necessarily. In a study of 26 women with diastasis recti, a natural curl-up narrowed the gap but distorted the linea alba. When women gently tightened their deep abdominal muscle first, the gap narrowed less, but the midline stayed more taut, which the authors suggest may help force travel across the abdomen.^[7] ACOG notes that abdominal strengthening exercises, including crunches and drawing-in, have been shown to reduce the gap after both vaginal and caesarean births.^[8]

Why, then, do we keep crunches and sit-ups out of plans until you are at least 12 weeks after birth and have had two weeks with no leaking, heaviness or pelvic pain? Because they are strong flexion movements that also raise pressure on the pelvic floor, which is still recovering. It is a cautious choice for the early months, not a verdict that crunches damage your body. When they come back, start small, and let doming and pelvic symptoms guide you.

When should I see a professional about diastasis recti?

The return-to-running guideline recommends that diastasis recti is screened and managed by a suitably qualified professional, such as a pelvic health or musculoskeletal physiotherapist with experience in it.^[9] A physiotherapist can look at how your whole trunk handles load, not just the gap, and build a plan around what you want to do, whether that is carrying a toddler up the stairs or getting back to the gym.

It's also worth a check if the gap isn't improving after several months, or if your tummy simply doesn't feel like it can support you. That is a reason to get help, not a sign that you have done anything wrong.

Diastasis recti often travels alongside pelvic floor changes, so our guide to pelvic floor recovery is a good next read. If you're thinking about running, see running after pregnancy, and for the full timeline, our guide to when you can exercise after birth. Everything fits together in our complete guide to exercise after birth.