15 Nov Understanding labour
Labour is caused by the contractions, muscular tightenings of the uterus, controlled by the hormone oxytocin. These contractions soften and thin out (efface) and open (dilate) the cervix making a passage through which the foetus will pass during birth.
The first stage of labour is from the start of labour until the cervix is 10cm or fully dilated. Initially during the early or latent stage of labour a woman may only be becoming aware of the labour and should continue normal gentle activities as far as she is able to. Once the labour is established, during the active phase, the contractions will become more frequent, last longer and get stronger. Eventually contractions will be coming every five minutes and lasting 40 to 60 seconds each as you reach the end of early labour. Each time the baby’s head is pushed down onto the cervix more oxytocin is released increasing the efficiency of the contractions and thus helping the labour progress. An increase in mucousy vaginal discharge may become evident, which may be tinged with blood – the so-called bloody show. This is perfectly normal, but if you see more than a tinge of blood, be sure to call your caregiver.
The transition phase happens between first and second stage. This is a phase of intense contractions and physical sensations. The hormone oxytocin surges and the woman in labour may experience strong contractions, coming very close together. She may lose her ability to keep things in perspective, find it hard to stay on top of each contraction and may experience nausea and vomiting. The cervix dilates from 8 to 10cm during transition. The contractions begin to change their effect from pulling the cervix open to pushing the baby down.
The second stage of labour is from the full dilatation of the cervix until the birth of the baby. Initially there will be a short rest period where the contractions become further apart but change in their function and sensation. This leads into an active phase of second stage where the woman in labour feels the urge to bear down and push with contractions. There is no longer any resistance from the cervix and each contraction will push the baby a fraction of the way along the birth canal (vagina). At this time the woman in labour is encouraged to push as she feels the urge to bear down during contractions until the baby is born.
The third stage of labour is the birth of the placenta (afterbirth). After the birth of the baby the uterus continues contracting, although these contractions are not as intense as the contractions during second stage. Once the shoulder of the baby has been born women are usually given an injection of artificial oxytocin to stimulate uterine contractions and hasten the separation of the placenta from the uterus. This also helps the uterus contract down to decrease the heavy bleeding that follows the birth of the placenta.
The fourth stage of labour is the crucial first hour or two after birth. During this time the baby is put skin to skin on the mother’s chest. This helps warm the baby and promotes the release of further oxytocin in the mother’s body to stimulate gentle uterine contractions to help control the bleeding from the uterus as well as helping the milk to flow in the breast ready for breastfeeding. This time of bonding between mother and baby is very important and should not be rushed. It is called the golden hour or the sacred hour.