what happens at birth
1 The first stage, when your contractions make your cervix gradually open up (dilate). 2  This is usually the longest stage. 3  The second stage of labour is when your cervix is fully open and you give birth.This is the part of labour where you help your baby move through your vagina by pushing with your contractions. The third stage of labour is after the birth, when your womb contracts and causes the placenta to come out through the vagina.he first stage of labour â dilation. The cervix needs to open about 10cm for a baby to pass through. This is what's called being fully dilated. Contractions at the start of labour help to soften the cervix, so that it gradually opens.