Diastasis recti is a separation of the two sides of your abdominal muscles along the strip of connective tissue that runs down the middle of your belly. That connective strip, called the linea alba, stretches and thins under sustained pressure, allowing the left and right halves of your “six-pack” muscle to drift apart. The result is often a visible bulge or ridge along the centerline of the abdomen, especially noticeable when you strain or sit up.
It is most common during and after pregnancy, but it can happen to anyone. Men, people who have never been pregnant, and even newborns can develop it when enough outward force pushes against the abdominal wall over time.
How Common Is Diastasis Recti?
A study published in the British Journal of Sports Medicine tracked women through pregnancy and beyond. About one in three women had a measurable separation by 21 weeks of pregnancy. At six weeks postpartum, that number jumped to 60%. By six months after delivery it dropped to about 45%, and by 12 months postpartum it settled back to roughly 33%. So while the gap does tend to narrow on its own in the months after birth, a significant number of women still have some degree of separation a full year later.
What Causes It
Pregnancy is the most common trigger. As the uterus grows, it pushes outward against the abdominal wall for months on end. The rectus abdominis muscles gradually lengthen and thin to accommodate that pressure. In some cases, the position of the baby concentrates force on the linea alba rather than spreading it evenly across the whole abdominal wall, which accelerates the separation.
Outside of pregnancy, anything that creates chronic or repeated outward pressure on the abdomen can contribute. Heavy weightlifting, persistent constipation, rapid weight gain or loss, and chronic coughing all increase intra-abdominal pressure. Men can and do develop diastasis recti from these kinds of sustained strains.
What It Feels Like
The most obvious sign is a visible bulge or “doming” along your midline when you do something that engages your abs, like sitting up from a lying position. Some people describe their belly as looking pregnant long after delivery, or notice a soft, almost squishy quality to the center of their abdomen.
Beyond the cosmetic change, some people experience a general feeling of core weakness or instability. Everyday tasks like lifting groceries, getting out of bed, or picking up a child can feel harder than expected. Lower back discomfort is frequently reported alongside diastasis recti, though research paints a more nuanced picture than you might expect. One retrospective study in BMC Women’s Health found that the rate of back pain was nearly identical in women with and without the condition (about 72% versus 70%). The same study found no statistically significant link between diastasis recti and pelvic organ prolapse or urinary incontinence, even when the gap was quite wide. That doesn’t mean those problems can’t coexist, but the separation itself may not be the direct cause.
How to Check for It at Home
You can do a simple self-assessment without any equipment:
- Lie flat on your back with your knees bent and feet on the floor.
- Place your fingers on your belly button, pointing down toward your pelvis, and press gently into your abdomen.
- Slowly lift just your head about an inch off the ground, keeping your shoulders down.
- Feel for a gap between the two ridges of muscle on either side of your midline.
If you can fit roughly two fingers or more (about an inch) into that gap, you likely have some degree of diastasis recti. The gap can occur at, above, or below the belly button, so it’s worth checking all three spots. This home check gives you a starting point, but ultrasound imaging provides more precise measurements. Diagnostic criteria based on ultrasound use specific thresholds at different points along the midline: greater than 20 millimeters at the belly button, greater than 14 millimeters just above it, and greater than 2 millimeters just below it.
Exercise as the First-Line Treatment
Core stability training is the standard starting point for managing diastasis recti. The goal is to retrain the deep abdominal muscles to generate tension across the linea alba, gradually drawing the two sides closer together and restoring functional support.
A randomized controlled trial tested an eight-week program that combined deep core exercises (diaphragmatic breathing, pelvic floor contractions, planks, and isometric holds) with traditional ab work, performed three times a week. Women did three sets of 20 repetitions per exercise, holding each contraction for five seconds. After eight weeks, the group doing the deep core program reduced their separation from an average of about 28 millimeters down to 20 millimeters. A comparison group doing only traditional ab exercises saw a smaller improvement, going from about 28.5 millimeters to roughly 24 millimeters. Both groups improved, but the deep core approach was significantly more effective.
The key exercises in effective programs tend to share a common theme: they activate the deepest layers of your abdominal wall and your pelvic floor before loading the outer muscles. Think controlled breathing drills, gentle pelvic floor lifts, and slow, stabilizing movements rather than fast, high-pressure ones.
Movements to Approach With Caution
Traditional crunches, sit-ups, and any movement that causes your belly to dome outward can increase pressure on the already-stretched connective tissue. During pregnancy and in the postpartum period, it’s important to avoid exercises that repeatedly spike intra-abdominal pressure, especially if you can’t maintain control of your pelvic floor throughout the movement. This doesn’t mean you can never do these exercises again, but reintroducing them too early or without proper core engagement can slow your progress or widen the gap.
When Surgery Becomes an Option
Surgery is not the first step. Guidelines recommend trying core stability training first, and surgical repair is typically considered only when that training has been given a genuine effort and symptoms persist. Candidates for surgery generally have a separation greater than 30 millimeters at the widest point, ongoing core instability that interferes with daily life, and a BMI within a specified range.
A study following 60 postpartum women who had surgical repair after failing to improve with exercise found long-term improvements in both core function and quality of life at three years post-surgery. The procedure itself is essentially a reconstruction of the abdominal wall, often performed alongside or similarly to an abdominoplasty. It’s a real surgery with a real recovery period, which is why it’s reserved for cases where conservative treatment hasn’t been enough.
Who Should Pay Attention
If you’re pregnant or recently postpartum and notice a ridge or bulge along your midline, some degree of separation is extremely common and often resolves partially on its own. Starting a structured core rehab program in the postpartum period can speed that process. If you’re a man or someone who has never been pregnant but you notice a similar bulge after heavy lifting, straining, or significant weight changes, the same principles apply: deep core training is the place to start, and a physical therapist who specializes in abdominal rehabilitation can tailor a program to your specific gap and symptoms.