text: child birth? what is it like? how do u start preparing? what exactly happens? the person with the best detail but informative is gauranteed 5 stars! : ) the birth starts with the onset of labour, which is usually marked by the beginning of regular uterine contractions. these are felt as tightenings either in the back or across the top of the womb. sometimes the baby's waters break before the beginning of the contractions or, more commonly, once labour is under way.  a mucous show is often passed through the vagina at the beginning of labour, which may have streaks of blood in it. some women pass the show days before going into labour, other women do not pass a show at all, so it is not a reliable sign of labour.   during a natural birth, the muscles in the uterus (womb) contract and it's this contraction that's felt as labour pains. labour is a painful experience, but breathing techniques learned in antenatal classes can make early labour less stressful.   the contractions cause the baby's head to be pressed down through the pelvis and against the inside of the cervix. this causes the cervix to stretch open (dilate) allowing the baby's head to pass through (descend) into the vagina and onwards into the outside world.   the birth begins when labour contractions start becoming frequent, intense and of sufficient duration to cause the cervix to open. at the beginning of labour, you will usually be examined externally (abdominal examination), to see how the baby is lying and to be certain that the baby is coming head first.   when labour starts, the cervix gets shorter (a process called effacement) and opens (dilates). the cervix is fully dilated when it has opened 10cm. during labour, it's important you don't start pushing before you are fully dilated, because there will be a danger of tearing the cervix.  once your cervix has fully dilated, the first stage of labour is completed and the second stage is about to begin. the first stage generally lasts up to 12 hours in a first labour and seven hours in subsequent deliveries, but each labour is different.  the second stage starts when your cervix is completely open (10cm). usually, there is a sensation of fullness in your vagina or bowel and you wish to push.   most women will find that the labour pains in the second stage of labour are more bearable, because you can now actively help yourself by pushing.   the second stage of labour ends with the delivery of the baby. it usually lasts for 45 minutes to two hours in a first labour and 15 to 45 minutes in subsequent deliveries.  during this stage the afterbirth (placenta) is delivered. the placenta is usually delivered within 5 to 15 minutes after the birth of the baby.   the last stage of birth is a co-operation between yourself and the midwife, although little effort is required to deliver the placenta.  after your baby's born, it's routine that you will be given an injection to stimulate the uterus to contract, which helps delivery of the placenta.   making the uterus contract in this way reduces the risk of heavy bleeding during delivery of the placenta (post-partum haemorrhage).