Since time immemorial, the pregnant mother undergoes a process called labour before the unborn child is delivered. It is only in recent times that this process has been circumvented by Caesarean section in certain groups of pregnant women.
Labour comes about following changes in the biochemical structure of the uterus, leading to regular uterine contractions of sufficient intensity, frequency and duration that results in the gradual thinning and opening up (dilatation) of the cervix.
Labour is a clinical diagnosis. Cervical dilatation without uterine contractions is suggestive of cervical weakness, whereas uterine contraction without cervical dilatation does not meet the definition of labour.
There are three stages in labour. The first stage involves the gradual cervical dilatation from 0 to 10cm, and the descent of the foetal presenting part, i.e. head or buttocks (breech position) through the mother's birth canal. The second stage involves the baby's birth, and the third stage involves the separation of the placenta from the uterine wall and its delivery.
Start of labour
The uterus, which comprises muscle, starts to contract regularly when labour commences. There is noticeable hardening of the abdomen during a regular, painful contraction, and softening when the contraction ceases.
The signs and symptoms of the start of labour include:
·A feeling that the foetus has dropped lower into the pelvis (lightening). This occurs between a few weeks to a few hours before labour starts.
·A pink or bloodstained vaginal discharge from the mucous plug at the cervix (called show), which is pushed out when the cervix starts dilating. This occurs between a few days to the start of labour.
·Backache and/or period-like cramps.
·A dribbling or gush of liquid when the "water bag" (waters) surrounding the foetus breaks.
If there is bleeding or the waters break, one should proceed to the hospital immediately, even if there are no contractions.
The uterus may contract on and off long before labour starts. These contractions (Braxton Hicks contractions) are sometimes mistaken for labour. They occur irregularly from the middle of pregnancy onwards and are usually not painful, although they sometimes can be painful.
There are ways of distinguishing true from false labour. Braxton Hicks contractions are irregular and do not increase in intensity with time. True labour contractions are regular and increase in intensity, with shortening of the interval between contractions as time passes.
Braxton Hicks contractions may stop with walking, resting or even a change of position. True labour contractions continue irrespective of what one does.
A practical method of distinguishing between the two is to time the duration of the contractions.
It would be prudent, when in doubt, to seek professional assessment by a doctor or midwife. A vaginal examination would provide definitive information about the start of labour.
This stage involves the gradual thinning and dilatation of the cervix from 0 to 10cm and the descent of the foetal presenting part, ie head or bottom (breech) through the mother's birth canal.
There are two phases.
The initial latent phase involves the thinning and dilation of the cervix from 0 to 3cm. This may take days or hours during which there are contractions, which may be regular or irregular. Some women feel the contractions whilst others do not notice them at all.
The subsequent active phase is characterised by strong and painful contractions, which last 30 to 60 seconds. The cervix dilates from 3 to 10cm. The interval between the contractions is between three to four minutes apart initially, and later, it shortens to about one to two minutes apart as the cervical dilatation gets to 8cm or more.
There may be an urge to go to the toilet as the presenting part exerts pressure against the rectum in its passage down the birth canal.
Once labour is established, the first stage lasts between 6 to 12 hours in those having their first baby. If one has had a baby previously, this stage is often shorter.
The mother and foetus are monitored throughout labour. This involves checking the mother's general condition, blood pressure, pulse, contractions and pain levels.
The foetal heart is monitored throughout labour to detect any changes which may indicate that the foetus is in distress. This is done by periodic listening every 15 minutes with a foetal stethoscope or a hand-held ultrasound device; or continuous electronic monitoring with a device called cardiotocograph (CTG) through a monitor fastened by a belt to the abdomen.
An alternative approach is through an electrode placed on the foetal head after the waters have broken and attached to the CTG.
It may be necessary to speed up labour if the contractions are not strong or frequent enough, or because the foetal position is abnormal. The doctor will explain the need and the manner in which this will be done.
During this stage, you can walk around the labour room if you feel like doing so. Fluids and food can be taken unless advised otherwise. (Pain relief will be discussed in a subsequent article.)
You should not feel embarrassed by your appearance or behaviour, as the midwife has seen it all. It is important to adhere to the midwife's advice to resist the urge to push until the cervix reaches 10cm dilatation.
This stage starts from the time the cervix is dilated to 10cm until the baby is born.
The contractions are strong, regular and appear to merge from one to another. There is an urge to bear down and push as if you have not passed motion for a few days.
This can be done by taking two deep breaths at the start of the contraction and pushing downwards for as long as is possible until the contraction stops. Another breath may be taken if necessary.
One needs to rest after each contraction and gather up the energy for the next contraction. The attending healthcare professional (accoucheur), who is a midwife or doctor, will provide the encouragement for this hard work.
There are various positions for this stage. They include lying in bed with pillows propping up the back, lying on the side, sitting, kneeling or even squatting.
What is important is to choose a position that one is comfortable with. It may help if you have tried out some of the positions beforehand.
If it is the first baby, this stage can last up to one to two hours. If one has had a baby previously, this stage is frequently much shorter.
When the presenting part appears at the vulva, which is the opening of the birth canal, the mother may feel that the area between the vulva and anus (perineum) is being stretched. The accoucheur will advise the mother to stop pushing and to pant some rapid short breaths.
This provides time for the perineum to stretch without tearing, thereby facilitating a gentle birth of the baby. However, the perineal skin may tear in some mothers.
If there is evidence that the perineum is going to tear or if there is a need to hasten the delivery, the accoucheur will ensure it is anaesthetised before making a cut in the perineum (episiotomy), which will be stitched up later.
After the foetal head is delivered, a gentle push is all that is necessary for the rest of the baby's body to be delivered. The umbilical cord is then cut. (A subsequent article will discuss vaginal breech delivery.)
This stage involves the separation of the placenta from the uterine wall and contraction of the uterus, which pushes the placenta out of the birth canal. The process takes between five to 30 minutes after the baby's birth.
The accoucheur usually administers an injection of a hormone called oxytocin to assist the process, and for the uterus to contract to reduce heavy blood loss, which occurs in some women.
The cuddling of the baby after birth helps in bonding between mother and baby. This can be done before the baby is cleansed of the messiness on the skin. As many labour rooms are air-conditioned, it is essential that the baby is kept warm.
It is the practice to inject a newborn baby with vitamin K to prevent haemorrhagic disease of the newborn. If there are objections to an injection, the midwife should be notified as oral doses are available.
The baby will be weighed, measured and examined by the midwife and/or paediatrician. An identification band with the mother's name will be attached to a part of the baby's body.
There are occasions when the mucous in the baby's nose, mouth and throat needs to be sucked out. There are also occasions when the baby requires assistance to start breathing.
The mother will then be assisted in washing and freshening up prior to transfer to the postnatal ward.