The rectus abdominis, or “six-pack muscles,” are a pair of long, flat muscles that run vertically down each side of the abdomen. These muscles help stabilize your trunk and hold in your internal organs. Diastasis recti occurs when these muscles separate during pregnancy or after you give birth, leaving a gap, a belly pouch, or a sense of abdominal weakness. The linea alba is the connective tissue that joins the two sides of the rectus abdominis muscle. As the belly expands during pregnancy, this connective tissue stretches and causes the muscle to separate from the linea alba. Pregnancy hormones help this connective tissue to relax as the baby grows and during labor and delivery. As postpartum hormones return to pre-pregnancy levels, the linea alba heals and the muscles come back together. If this doesn’t happen in three to six months, there may be a gap that won’t close without treatment. Approximately 40 percent of women still have some degree of diastasis six months after giving birth. A diastasis recti can look like the top of a loaf of bread or a ridge protruding from your midline. This ridge becomes more prominent when you strain and hold your breath while sitting up, lifting, or even coughing and sneezing. The ridge may go away or cave in when you lie down or relax your abdominal muscles.