What is Diastasis?

Diastasis is a medical term that refers to the abnormal separation of muscle groups or other anatomical structures. One of the most common forms is diastasis rectus, also known as abdominal diastasis, which frequently affects pregnant or postpartum women. However, it can also occur in newborn infants due to incomplete development of the abdominal muscles. In either case, the condition is characterized by a separation of the muscles at the point where they are normally joined by the band of connective tissue called the linea alba.

In pregnant or postpartum women, separation of the abdominal muscles occurs due to the expansion of the region in response to a growing uterus. It may also occur from sudden, strenuous, or repeated physical exertion. The separation typically produces a ridge-like bulge that can be felt by hand or, in some cases, may even be visibly apparent. In postpartum women, a simple self-test to check for this condition involves lying on the floor with knees bent and one hand on the abdomen while lifting the head and shoulders slightly, as though just entering a sit up or crunch exercise. If a gap is detected by hand that is more than two fingers in width, then the condition is likely present.

A related condition known as symphysis pubis diastasis may also impact pregnant or postpartum women. This condition is characterized by an exaggerated separation of the pelvic bones. Normally, hormones such as relaxin secreted during pregnancy trigger the fibrous ligaments supporting the pelvic bones to stretch, causing a separation between them from a pre-pregnancy average of 0.20 inches (5 mm) up to 0.35 inches (9 mm) to accommodate a growing baby and facilitate delivery. Expansion of the bones beyond this range, or a complete separation due to physical trauma or injury, typically results in impaired movement and chronic pain. The condition is usually treated with the application of a pelvic girdle and bed rest or, in some cases, surgical pelvic fixation.

Surgical intervention to remedy the separation of the abdominal muscles occurring after childbirth is also sometimes addressed with abdominoplasty, a procedure commonly recognized as a tummy tuck. However, unless a hernia tear or a complete separation of the muscles is indicated, most women recover naturally by committing to regular exercises intended to target the abdomen. If necessary, the woman may choose to consult with a therapist specializing in physiotherapy and the treatment of musculoskeletal disorders.

Generally, abdominal diastasis in newborns is not a cause for concern since the condition usually corrects itself as the child physically matures. However, if a hernia is present within the abdominal wall, corrective surgery may be indicated. It should also be noted that while this condition is fairly common in newborns it occurs more frequently in premature babies and those of African American descent.