Labour - what happens in the three stages

Know what to expect when the contractions start, with Christine Hill’s blow-by-blow account of labour

There are three main stages to labour. The third stage is the aftermath once your baby’s born, stage two should be the hard work bit with a good end result, while the first stage can be long and tiring. It’s easier to understand what’s going on with your body during labour, if you brush up on a bit of basic anatomy first:

The uterus (womb) is the shape of an inverted pear It’s made of muscle fibres which run from top to bottom The opening of the womb (the stalk end) is called the cervix The cervix is made up of much stronger muscle fibres which are less elastic. It has to remain tightly closed during pregnancy, so the baby doesn’t fall out The end of the cervix rests at the top of the vagina.

First stage of labour

What’s happening?
1. When the baby’s ready to be born, the muscles of the uterus start to contract, in order to pull the cervix open.
2. The cervix has to dilate to 10cms, which is the average width of a baby’s head.
3. As well as the cervix dilating, the contractions also have to rotate the baby’s head.

The position of your baby’s head is one of the factors that dictate the type of labour you’ll have. Because of the shape of a woman’s pelvis, when a baby engages, she lies with her head facing her mother’s hip. But it’s easier if babies are born with the narrowest diameter of their head coming first, and that’s the crown or top back bit. (Think of pulling a polo necked sweater over a child’s head if you start at the back of the head it slides down OK; if you start at the front of the head, it gets stuck.) So during labour, the contracting uterus is doing two things at the same time:
1. Dilating the cervix
2. Gradually turning the baby’s head round so she faces your spine when she’s born.