Your amazing birth muscles

Your amazing birth muscles

Your body is amazing. Full stop.

I bet you haven’t thought too much about how the muscles in your uterus work, have you? I know that for many women, understanding the power of their incredible body is very empowering and comforting, so let’s come to a simple understanding about how this set of birth muscles are some of the strongest and most effective muscles you have in your body,

Your uterus allows a tiny, microscopic ball of cells to nestle in, set up shop and grow. Before you got pregnant it was around the size of your fist and was tucked down in your pelvis, weighing around 100 – 150 grams. As your pregnancy progresses your uterus grows to accommodate your growing baby and by the time you are full-term, your uterus will weigh about 1.5kgs. It’s at this point when baby is ready to arrive that this marvellous set of muscles transforms into a powerful machine that births your baby out into the world.

Three layers of muscles make up the uterus and all of them work together.

The outer muscle layer (as pictured above on the left ) is full of strong vertical fibres concentrated at the top of the uterus, reaching up and over. When you go into labour these muscles move up and down; drawing up, pressing down.

The middle muscle layer (which is not pictured) is full of blood vessels delivering oxygenated blood to all muscle layers.

The inner muscle layer (see the right-hand image) is full of soft, flexible, circular muscles. They circle the base of the uterus, near the opening – the cervix.

In your pregnancy, the soft circular inner muscles are holding the cervix closed, keeping your baby safe inside. But in labour, they need to relax. They allow the cervix to soften, thin and open (which is what is happening when you’re dilating).

As these soft circular muscles draw back, they’re also drawn upwards so that they collect at the top of the uterus ready to help support the next stage of birthing.

When you are fully dilated the Natural Expulsive Reflex kicks in and the muscles actively help baby get down, through and out into the world.

It’s thanks to the outer muscle layers that, when they are working beautifully, they draw these circular muscles up and away from the cervix so you’re able to fully soften, dilate, open.

Imagine the process like a dance – a complex interaction between the muscles. The best thing is that you don’t need to know all the steps of the dance, you just need to sit back, relax and allow it all to play out, as it will.

One of the most important things to know is that the muscles work most efficiently and comfortably when you are calm and relaxed and no tension is present.

It’s all designed to work beautifully, so start recognising your body as the incredible superbly-designed machine that it is.

Throughout your pregnancy you may feel the muscles of your uterus tighten and harden, this is just the muscles warming up, doing a bit of a flex. It’s called Braxton Hicks and you’ll often find that if you use the breathing techniques you are learning the sensations will fade away.

A helpful visualisation to use in your labour and birthing is to imagine the powerful work that these birth muscles are doing. The outer muscles drawing up and pressing down, the soft relaxed inner muscles relaxing and opening. By thinking about how our body is working effectively and efficiently helps us to think positively about the process – your body is doing amazing work.

Your body was designed to birth your baby. But, there’s a big topic we need to consider getting ‘out of the way’ which is – Fear. We need to be free of fear and relaxed to fully allow our body to do the work it’s designed to do.


“We both loved our HypnoBirthing course and have really missed it since it’s ended. We found the course gave us a toolkit to not only prepare for the birth but to also cope with the general stress of big life changes. The strategies we developed during HypnoBirthing will continue to be applied even after the birth of our child. It really is a toolkit for life!”

Sarah and Gareth


… for the partners — do not underestimate your value, I know I could not have done it without Warren and our bond has been strengthened by such a powerful and emotional shared experience. He is my rock and already the best father imaginable.”


Positive Births

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