Here is some more information about diastasis recti and how the intra-recti distance changes across postpartum period.
What is divarication of the rectus abdominus muscles?
The abdominal wall is a muscular structure that serves to protect the abdominal viscera, maintaining their intra-abdominal position against changing gravitational forces and increases in compartmental pressures. Diastasis or divarication of the rectus abdominus muscles is a separation of the two muscles, usually as a result of the linea alba thinning and stretching (1). The extent of the divarication may be measured by the inter-recti distance. Once separated, the function of the anterior abdominal wall may become comprised (2). Secondary divarication is an acquired phenomenon and may result from excessive exercise, significant weight loss, and most commonly following pregnancy (3). In this condition, the altered angle of attachment, hence the angle of pull of the muscle, is a mechanical weakness.
Diastasis recti in pregnancy
The study examining women after childbirth demonstrated that women had an increased intra-recti distance in the antenatal period. Relaxin has been suggested to induce ligamentous laxity of the body joints during pregnancy. It has been shown that the recti fascia in pregnant women is weak, with decreased tensile strength, such that tissue creep and stress relaxation of the recti fascia, especially during the rapid foetal growth period, is necessary. This may also explain the second sudden increase in intra-recti distance demonstrated in the second post-term week. In all measurements in the antenatal period, the distance is largest at the level of the umbilicus where it may be a potential weak point.
Postpartum changes in muscle structure
Changes in intra-recti distance immediately postpartum is a conflicting issue. In the case, when woman pushes very hard during bearing down in the lithotomy position in the second stage of labour, the upper rectus abdominis is expected to work considerably. With the already stretched linea alba, the force and pressure generated from bearing down may have further stressed the anterior abdominal wall, causing further stretching and thinning out of the linea alba (4). While during regular childbirth intra-recti distance is expected to decrease immediately postpartum, due to the removal of stretch on the anterior abdominal wall.
The resolution of intra-recti in the postpartum period progressed at different rates and in different patterns. It has been reported that the intra-recti distance at eight weeks postpartum decreased to a level similar to 22 weeks gestation. However, other studies demonstrated that intra-recti distance at 12 weeks postpartum had not even resolved to the level at 36 weeks gestation. As it would be expected that intra-recti distance would resolve gradually with time in the postpartum period. Nevertheless, external factors may complicate the natural resolution of intra-recti distance. When the tissue is still under the effect of relaxin, increased physical demands may stress the linea alba further. Moreover, muscle fatigue may be responsible for some variability. Other factors may also account for some variability. Foetal position may affect the intra-recti distance. Individual differences in tissue architecture (especially collagen) may play an important role in determining how much stress and strain the tissue can sustain, how it would react to the stress and hormones and recover afterwards.
Activity in postpartum period
Considering exercises, the anterior abdominal wall may not be protected sufficiently to withstand the additional stress from increased activities. Therefore, women should refrain from vigorous physical activities and maintain correct posture in activities like lifting and carrying their baby, baby bathing and pushing the pram, for at least 12 weeks after delivery.
1. Moore KL, Dalley AF (2006) Clinically orientated anatomy, 5th edn. Lippincott Williams and Wilkins, Baltimore
2. Hickey F, Finch JG, Khanna A (2011) A systematic review on the outcomes of the correction of diastasis of the recti. Hernia 15: 607-614
3. Palanivelu C, Rangarajan M, Jategankar PA, Amar V, Gokul KS, Srikanth B (2009) Laparoscopic repair of diastasis recti using the ‘Venetian blinds’ technique of placation with prosthetic reinforcement: a retrospective study. Hernia 13(3): 287-292
4. Hsia M, Jones S (2000) Natural resolution of rectus abdominis disatasis. Two single case studies. Aust J Physiother 46(4): 301-307
