Diastasis recti

How it works

The rectus abdominis is the long flat muscle at the front of the belly, the one that shows as a six-pack². It is two muscles side by side, joined down the middle by a band of tough tissue called the linea alba³. The gap between the two halves is normally narrow, about the width of a finger or less above the navel¹.

During pregnancy the growing uterus pushes outward. The linea alba stretches and the two halves drift apart¹. This is normal. Some degree of separation is found in nearly all first-time mothers by the end of pregnancy⁵. After birth the gap usually narrows over months. In about a third of women it is still wider than normal a year later⁴.

Men and non-pregnant women get it too, more often with age and a large belly⁶. Newborns can have it too, especially if born early¹.

The usual sign is a soft ridge or dome down the middle of the belly when you lift your head from lying down, or when you strain¹.

How common it is

The pregnancy figures come from studies that measure the gap between the two muscle halves with ultrasound or by counting finger widths, before and after birth⁴⁵. Nearly all first-time mothers show some widening late in pregnancy⁵. Around a third still measure wide a year after delivery⁴. These are the best-studied numbers. For men, non-pregnant women, and children, there are few studies. One CT study of 329 adults, men and women, reports a gap wider than 2 cm in 57% of them⁶. How common it is outside pregnancy is still not well known.

Try it

1. Lie on your back with your knees bent and feet flat on the floor.
2. Put the fingertips of one hand on the midline of your belly, just above the navel, pointing toward your feet.
3. Lift your head and shoulders a little, as if starting a sit-up, and press your fingers gently down.
4. Feel for the edges of the two muscle halves on either side of your fingers. Count how many fingers fit in the gap.
5. Repeat just below the navel.

A finger count is not a diagnosis.

Is it a problem?

For most people, no. The muscle is not torn. The band between the halves has stretched. Two studies of new mothers show no link to more low back or pelvic pain⁴⁵. It often improves with time¹. A doctor or a physiotherapist can assess it and advise on exercise.

See a doctor if:

• the bulge is painful,
• the bulge cannot be pushed back in,
• you are not sure whether it is a separation or a hernia.

A hernia is a different problem, where tissue pokes through a hole, and it needs a proper check.