During pregnancy, increased pressure on the abdominal wall can cause a condition called diastasis recti. Diastasis recti looks like a ridge, which runs down the middle of the belly area. It stretches from the bottom of the breastbone to the belly button, and increases with muscle straining. Women may develop 2 finger’s width of separation of the abdominus recti muscle (down the centre line of the belly).
The condition is more common for women who have had multiple pregnancies. Severe abdominal exercises should be avoided after the twelfth week of pregnancy.
Usually the condition will heal on its own.