Management of labour

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Slow Progress

Slow labour is a rate of <1cm/h after the latent phase. Prolonged labour is >12h after the latent phase.

Powers

Ineffective uterine action is the most common cause of slow progress in labour and happen almost exclusively in nulliparous women. In multiparous women, malpositions and malpresentations must be checked for carefully. It is managed using augmentation i.e. amniotomy with oxytocin.

Hyperactive uterine action is excessive, prolonged and frequent contractions. This can cause fetal distress and this distress indicates Caesarean section.

Passenger

If you don't know the nomenclature for the different presentations, go here.

Malpositions

Breech presentations (where the baby's bum is the presenting part) is usually discovered before labour. It can be delivered vaginally or by Caesarean and about 50% are successfully delivered vaginally. It is more common in premature labour.

Transverse lie (where neither bum nor face but arms or back are the presenting part i.e. the foetus is lying transversely) is impossible to deliver vaginally. Elective Caesaerean is indicated

External cephalic version (ECV) is an attempt to turn the baby from breech to cephalic presentation. Terbutaline is given to relax the uterine muscles and the obstetrician attempts to turn the baby. Fetal heart monitoring is done before, during and after the procedure and an ultrasound scan is done beforehand.

Malpresentations

Occipito-posterior (OP) presentation occurs in 5% of deliveries and generally results in longer and more painful labour. Delivery is by flexion of the head the head, rather than extension, over the perineum and towards the abdomen. Instrumental delivery can turn the head round to face the right way.

Occipito-transverse (OT)" needs to be manually rotated by instrumental delivery, either forceps or a Ventouse if the labour has already reached the second stage.. Brow and Face presentations must be delivered by Caesarean section.

Pain Relief

There are basically three main areas: non-medical, drugs and anaesthaesia.

Non-drug

Transcutaneous electrical nerve stimulations (TENS) applies a mild electrical current to the skin via electrodes. Theoretically, it stops pain pathways working effectively but the evidence is pretty rubbish. Complementary therapies can also be used along with a water or birthing pool (not necessarily the same as a water birth). These are offered as they are cheap and can be helpful to some women, even if only psychologically.

Drugs

Nitrous oxide and oxygen (Entonox) affectionately and colloquially known as gas and air is as 50:50 mixture which is used during the first two stages of labour. It is under the mother's control and works quickly and lasts for a short period of time. Half of women achieve satisfactory relief. It is also very safe.

Pethidine is an opioid analgesic given intramusclarly which takes around 15 mins to work and lasts 2-3 hours. It's efficacy is debated. Remifentanil is patient-controlled analgesic which has been proven effective in small, intermittent boluses.

(It is important to note that with opiate analgesia, babies may develop respiratory distress after delivery which is treated with naloxone.)

Anaesthetic

Epidural

This involves blocking the central nerves using local anaesthetic, using a needle and catheter to adminster the medicine very close to the nerves which transmit pain. It is the most effective way to relieve pain during labour and provides complete relief in 95% of cases. There are however some disadvantages:

  • Increase duration of 2nd stage
  • Increased rate of instrumental deliver
  • Dural tap in 1% - the needle penetrates the dura and goes into the CSF which causes a severe headache.
  • Transient hypotension (20%)
  • Higher number of abnormalities in fetal heart rate (possible relation to point above)

There is also the possibility of an ambulatory epidural. The dose is lower so the woman can still walk. Combined spinal-epidural is being introduced as it reduces the adverse effects of an normal epidural.

Local

When instrumental delivery or episiotomy/perineal tear repair is necessary but an epidural has not already been given, local analgesia is used

  • Pudendal nerve block uses lignocaine (10ml, 0.5%) injected behind the ischial spines of the pelvis via vagina.
  • Perineal nerve infiltration is acheived with lignocaine injection (20ml, 0.5-1%) around the posterior fourchette (the point where the labia minora meet).

Foetal Monitoring

This about making sure that the foetus is OK. This basically consists of cardiotocography (CTG) and if fetal distress is suspected, fetal blood sampling.

Cardiotogography

All mothers who have babies in hospital have periodic foetal heart rate monitoring. This is using a Doppler ultrasound. Continuous fetal heart rate monitoring is NOT indicated in normal labour with no associated risk factors and is only used when there is a reason to. It is only an indirect guide to the health of the foetus but since it is one of the few ways of being able to tell, many treat it as a direct monitor.

Indications

Having said this, there are a variety of indications for CTG and they can be split into three different sections: risks in the mother, risk to the foetus and risks during labour.

The following table classifies CTG findings:

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