During pregnancy, the growing uterus stretches the muscles in the abdomen. This can cause the two large parallel bands of muscles that meet in the middle of the abdomen (rectus muscles) to become separated by an abnormal distance — a condition called diastasis recti or diastasis recti abdominis.
Diastasis recti might cause a bulge in the middle of the abdomen where the two muscles separate. The condition might be noticeable only when the abdominal muscles are tense, such as when you move from lying down to sitting up. Diastasis recti can weaken the abdominal muscles, causing lower back pain and making it difficult to lift objects or do other routine daily activities.
You might be more likely to develop diastasis recti as a result of pregnancy if you have carried multiples or a large baby to term and are of small stature and fit or are age 35 or older.
If you think you have diastasis recti, talk to your health care provider. After childbirth, certain exercises can help you regain some degree of abdominal strength. A physical therapist can help determine which exercises would be right for you.
If abdominal muscle weakness associated with diastasis recti is interfering with your daily activities, surgery might be recommended to repair the muscle separation. If you're bothered by the bulge in your abdomen, you might also consider surgery for cosmetic reasons.