Labour

Labour is the process of Uterine contractions and Cervical dilatation that enables the delivery of a viable foetus, placenta and membranes. It's diagnosed when there are regular and increasingly painful uterine contractions (5 mins apart) that bring about progressive cervical effacement and/or dilatation. This process is monitored with a Partogram, which has 2 aspects:

• Alert line - Line drawn at a rate of 1cm/hr from when cervix enters the active phase

• Action line - Parallel line drawn 4cm to the right of the alert line

  • Intervention is indicated if labour progresses to the right of the Action line (deemed to be slow labour)

First Stage

The overall outcome of this stage is to reach full cervical dilatation. There are 2 phases involved here:

1. Latent phase - Cervix becomes fully effaced and slightly dilated

2. Active phase - Cervix becomes fully dilated

The main substance at work here are Prostaglandins.

Second Stage

The overall outcome of this stage is to deliver the foetus. The steps involved are:

• The baby passes through the pelvic fossa sideways before rotating its head downwards

• Mother pushes until crown of head is out

  • Hand is placed on the head to hold it in place, prevent a tear and the baby being “spurted” out

• Once the whole head is out, it then turns back to the side, with both shoulders in a vertical plane

  • Anterior shoulder (behind pubic symphysis) is pulled out by pushing the baby downwards

  • Posterior shoulder pulled out by pushing the baby upwards

A major complication that can occur here is Labour Dystocia, which means obstructed labour. Here, there's failure of the cervix to dilate, and head to descend, with increased Caput and Moulding. Caput is oedema of the scalp due to the tourniquet effect of the cervix during labour. Moulding is the reduction in foetal head diameter due to overlapping sutures and compressible nature of bones and Fontanelles.

Third Stage

The overall outcome of this stage is to deliver the placenta and membranes. Here, the left hand of the obstetrian/nurse is placed above the pubic symphysis to guard the anterior uterine wall. Then, there's controlled cord traction until the placenta is fully delivered.

Complications:

• Retention of placenta

• Post-partum haemorrhage (PPH)

• Perineal tear

• Herniation of uterus - ensure placenta is fully detached before pulling

To actively manage this stage, IM Syntometrine (Oxytocin + Ergometrine) given on delivery of the anterior shoulder. Complications with giving this include:

• Hyperstimulation

• Iatrogenic foetal distress

• Uterine rupture

• ADH effect and Water intoxication with high dose and prolonged use

  
  

Slow Labour

Causes - 3 P’s:

• Power - Inadequate uterine contractions (Most common cause)

• Passage - Inadequate pelvis (short stature, previous pelvic injury, tumour)

• Passenger - Foetus may be large or may present with a sub-optimal diameter

Complications:

• Maternal dehydration/exhaustion

• Maternal and Foetal infection

• Foetal distress

• Operative delivery

• Uterine rupture

• PPH

• Increased maternal and foetal morbidity

• Vesicovaginal fistula