Prevalence and risk factors for diastasis recti abdominis: a review and proposal of a new anatomical variation

Abstract

Purpose: Diastasis recti abdominis (DRA) or rectus diastasis is an acquired condition in which the rectus muscles are separated by an abnormal distance along their length, but with no fascia defect. To data there is no consensus about risk factors for DRA. The aim of this article is to critically review the literature about prevalence and risk factor of DRA.

Method: A total of 13 papers were identified.

Results: The real prevalence of DRA is unknown because the prevalence rate varies with measurement method, measurement site and judgment criteria, but it is certainly an extremely frequent condition. Numbers of parity, BMI, diabetes are the most plausible risk factors. We identified a new anatomical variation in cadaveric dissection and in abdominal CT image evaluation: along the semilunar line the internal oblique aponeurosis could join the rectus sheath with only a posterior layer, so without a double layer (anterior and posterior) as usually described. We conducted a retrospective review of abdominal CT images and the presence of the posterior insertion only could be considered as a risk factor for DRA.

Conclusion: Further studies with large sample size, including nulliparous, primiparous, pluriparous and men too, are necessary for identify the real prevalence.

Keywords: Abdominal rectus muscle; Diastasis recti abdominis; Intra-rectus distance; Risk factor; Semilunar line.