Causes of Diastasis Recti Abdominis
Diastasis recti abdominis results from mechanical stretching and hormonal weakening of the linea alba, most commonly caused by pregnancy, but also occurs in men due to chronic abdominal distension, obesity, aging, improper exercise techniques, and familial connective tissue weakness.
Primary Causes in Women
- Pregnancy is the predominant cause in the female population, with mechanical stretching of the linea alba tissue during gestation leading to separation of the rectus abdominis muscles 1
- The condition is highly prevalent in late pregnancy and the postpartum period, though prevalence decreases after delivery 2
- Hormonal changes during pregnancy contribute to connective tissue laxity, facilitating muscle separation 1
Primary Causes in Men
- Rectus muscle diastasis without skin laxity is common in men older than 30-40 years of age 3
- History of weight fluctuations and obesity-related chronic abdominal distension are significant contributing factors 3
- Improper exercise techniques, particularly weightlifting and full-excursion sit-up exercises, progressively separate the rectus muscles over time 3
- Familial weakness of the abdominal musculofascial tissues represents an inherited predisposition 3
- Advancing age contributes to progressive weakening of the linea alba 3
Mechanism of Development
- The condition involves disintegration of both rectus abdominis muscles to the sides, accompanied by extension of the linea alba tissue and bulging of the abdominal wall 1
- Chronic or intermittent abdominal distension creates sustained pressure that stretches the linea alba beyond its elastic capacity 3
- While DRA may result in herniation of abdominal viscera, it is not a true hernia 1
Important Clinical Distinction
A critical pitfall is confusing diastasis recti with other abdominal conditions. The diagnosis is established when the inter-rectus distance exceeds 2 cm 4. Unlike hernias, there is no fascial defect—only stretching and thinning of the linea alba 1. This distinction is essential because management strategies differ fundamentally from hernia repair.
The evidence consistently demonstrates that while pregnancy dominates as the cause in women, men develop diastasis recti through entirely different mechanisms related to mechanical stress, improper training, and constitutional factors 3. Recognition of these distinct etiologies is crucial for appropriate counseling and prevention strategies.