Tummy Muscle Separation in Pregnancy - It's a needed & necessary thing. Abdominal doming however is not!
Tummy muscle separation is a needed and necessary part of pregnancy. At TPS our pregnant patients are often concerned about the changes they are observing in their tummy muscles. But we assure you that these changes are a normal and necessary adaptation that occurs in 66-100% of pregnant women.
Tummy muscle separation (known medically as rectus abdominis diastasis) refers to an increased distance between your abdominal muscles. To explain this further let’s first talk about your anatomy – Your left and right abdominal muscles join together at the front via a central ligament/connective tissue called your linea alba (easy to remember by thinking about actress Jessica Alba).
During pregnancy a hormone called relaxin gets released that loosens your connective tissues making them stretchier. This relaxin allows your linea alba to soften, and the gap between your tummy muscles to widen. This thinning and widening of your linea alba creates room for your baby.
In your third trimester, about an 8cm gap between your abdominal muscles is considered normal. As stated previously, these changes occur to create room for your growing baby but also to preserve the function of your abdominal muscles. In other words, if your linea alba widens that means your tummy muscles won’t have to lengthen quite as much. This will in turn preserve your core and its ability to stabilise and support your trunk and pelvis.
As your linea alba thins and widens you may start to notice doming in the centre of your tummy with coughing, laughing, getting out of bed and with certain exercises.
Although tummy muscle separation is a normal and necessary part of your pregnancy, doming in the centre of your tummy is not.
Doming, although a commonly observed side effect of tummy muscle separation, should not be ignored. As it is ultimately a sign that the load on your tummy is beyond the capability of your linea alba. If doming occurs repetitively it may result in further thinning and subsequent weakening of the linea alba. This can lead to a poor abdominal recovery postnatally, such as excessive or prolonged tummy muscle separation and/or abdominal hernia.
If you notice abdominal doming please seek the advice of a trained health professional. At TPS we are strong advocates for prenatal physiotherapy assessments being a standard part of your antenatal care. A prenatal assessment includes a thorough abdominal assessment, reviewing the function of your deep core. A well functioning deep core can help to prevent and/or treat abdominal doming in pregnancy. In our next blog we will discuss why the deep core is so important when it comes to tummy muscle separation.
Reference
Mota et al. 2018 Normal width of the inter-recti distance in pregnant and post - partum primiparous women.