Diastasis Recti is "caused by a stretching of the linea alba, the ... tissue that connects the two panels together in the middle,” explains Karen S. Weeks, physical therapist with the Northwestern Medicine Integrated Pelvic Health Program in Chicago.
Usually, this gap occurs during the last trimester and affects those with a multiple baby pregnancy, larger baby delivery or women who are over 35.
There are some exercise no-no's to help avoid diastasis recti. Sit-ups should be avoided. You don't want to do any repetitive flexion of the spine during this period, it will just agitate and potentially create more of a separation. On the other hand, it is very important to do core isolated stabilizing exercises like plank, side plank, paloff press, and anti-rotational exercises before and after the pregnancy. These exercises will help hold together and tighten the muscles of core so that further separation is avoided.