Normal Labour

Definition: labour is called as normal when:

• It is spontaneous in onset,
• At term (after 37 completed weeks)
• with singleton fetus in vertex presentation,
• minimally assisted vaginal delivery and
• normal maternal and neonatal outcomes.

Normal labour is divided into four stages.

First stage

• The first stage starts with onset of regular uterine contractions and ends with full dilatation of cervix (10 cm).

First stage can be divided into:

• Latent phase:
• It is termed when cervix is less than 3 cm dilated. Here, contractions occur at an interval of 5- to 10-minutes.
• With time the contractions become stronger with shorter intervals, whereas the cervix dilates at a very slow rate
• Active phase:
• It starts when the cervix is 3-4 cm dilated. The cervix now dilates at a rate of 0.5-1.0 cm/hour.
• More the cervix dilates, stronger the uterine contractions get. There is an urge to push down even before the cervix if fully dilated.
• Pushing is undesirable until the cervix is fully dilated as this may lead to maternal exhaustion and unnecessary interventions later on.
• Maternal pelvic examination is done every 4 hourly to keep a check on cervical dilatation.

The first stage of labour, on an average lasts for 5 to 8 hours depending on the maternal factors like age, parity, BMI etc. However, it should not cross 18 hrs. in primigravida and 12 hrs. in multigravida. This is a red flag sign and warrants immediate intervention.

Management

• It primarily includes, continuous reassurance and counseling of the pregnant lady in labour.
• Maternal pulse and BP are measured every 4 hrly.
• Check is kept on maternal uterine contractions.
• The fetal heart rate is measured for at least 1 minute immediately after a contraction. Normal FHR varies between 110-160 beats per minute (bpm)
• 4 hrly. pelvic examination is done to keep check on cervical dilatation and also gives idea of fetal presentation and station of presenting part.

Second stage

It starts with the full dilatation of cervix i.e. 10 cm and ends with the birth of the baby.

• Contractions become stronger with shorter intervals (occur at 2- to 5-minute intervals and last 60-90 seconds).
• There is continuous bearing down by the mother as an effort to push out the baby.
• It usually lasts for about 2 hours in primigravida and 1 hour in multigravida.
• As the baby descends down, large part of the head can be seen through the cervix.
• Fetal head is born with the forehead first, followed by nose, mouth and chin. Subsequently, the shoulders, trunk and legs follow.
• The baby starts to breathe and cry as soon as it is outside.

Management

• The doctor/nurse is present at all times to keep note of the degree of pain and to encourage pushing during contractions and relaxing with deep breathing in between.
• Fetal heart rate and contractions are measured ever 5 minutes
• Instrumental delivery is considered in cases where second stage lasts >2 hours in primigravida and >1 hour in multigravida.
• Liberal episiotomy is given under local anaesthesia as soon as crowning is seen.

Third stage

It lasts from the birth of the baby to the delivery of the placenta and membranes.

• It usually takes up to 5 minutes, but can be longer.
• There is contraction and retraction of the uterine muscles thereby reducing the surface area of placental bed and preventing haemorrhage

Management

Active management of third stage of labour (AMTSL) is preferred over traditional conservative management.

• Intra-muscular injection of oxytocin 10 IU with the delivery of the anterior shoulder.
• Controlled cord traction- here slight downward and backward traction is applied on the umbilical cord after clamping and cutting it. Simultaneously, upward and forward push is given to uterine fundus to prevent inversion of uterus.
• Fundal massage- gentle massage is given to the uterine fundus till it is strongly contracted.

Fourth stage

This is the last stage of labour. Here the mother is kept under observation for 1 hour. Vitals are monitored along with amount of bleeding and uterine contraction. It is very crucial period as strict vigilance during this time can help in timely diagnosis and management of post-partum haemorrhage and significantly reduce maternal morbidity and mortality.