Because of the lack of agreement on when rectus diastasis (RD) is pathologic, the aim was to investigate indications for surgical repair. This study presents classifications of RD, current knowledge on the relation to pregnancy, and conservative and surgical management. A systematic search in Pubmed, Embase, Cochrane, and Cinahl revealed 437 studies. Inclusion criteria were applied according to the above mentioned subjects of interest. In total 28 studies were included, representing 3725 patients, 11 of these by assessing reference lists of included studies. Only one RCT was found; most studies were case-series lacking statistical analysis. RD was common in post-partum women. Antepartum activity level may have a protective effect on RD and exercise may improve post-partum symptoms of RD. Repair was done during abdominoplasty or laparoscopically. The patient-satisfaction was high and long-term recurrence was reported by one study, while five reported no recurrence. Overall major complications were few, while minor complications were primarily seroma and wound complications. RD is by itself not a true hernia and, therefore, not associated with the risk of strangulation. Repair is mostly done due to cosmetic reasons. The condition does not necessarily require repair, and conservative management may be an alternative. If done, the protrusion of the abdomen, rather than the diastasis itself should influence the decision of repair. It is recommended that future studies use the established classifications (e.g. Beer, Rath, or Nahas) when reporting RD and long-term outcome of treatment. Comparison of surgical techniques and studies that address and compare conservative management with surgery are needed.
Keywords: Rectus abdominis diastasis; abdominal wall; abdominoplasty; conservative management; diastasis recti; divarication recti; linea alba; physiotherapy; pregnancy.