Induction in Labour

Induction of labour has become an ever increasing fact of life. Regardless of whether you believe social inductions to be good or bad, for some couples, timing of delivery is every bit as important as a medically required induction. I care for many women whose partners travel overseas. For them, induction of labour was the only way DAD would see the baby before it was 6 months old. 

Medical Induction:  Approximately 10% of all pregnant women will require an induction of labour for medical reasons.
Labour is induced if there is more risk in allowing the pregnancy to continue than there is in earlier delivery. Situations where this might occur include:
Social Induction: This means that for various reasons, couples decide that waiting for spontaneous labour has disadvantages that are outweighed by the advantages of undergoing an elective induction of labour.
Why would a woman want to be induced? Their reasons vary and most have thought through the process before making their request.
I have had occasions when the husband is only going to be in town for 48 hours around the expected due date. Timing becomes essential. Other women may have previously had an extremely rapid labour and are in danger of delivering in the car on the way to hospital.

Method of Induction: Before discussing the different methods used to induce labour, it is important to distinguish the induction from the labour. Medical people talk about an: -

Here I will only be discussing the Induction process: -


Prostaglandin:

This is perhaps the most popular method of induction used by Obstetricians. CERVADIL / Misodel is used in preference to Prostin gel as it gives a more even sustained release with a lower risk of hyperstimulation. It is inserted in the vagina, near the cervix. It acts by stimulating the normal cascade of chemicals required to initiate normal labour.


PRO’S: 
CON'S  
What to expect: 

  You will need to arrive at the Maternity unit at 8:30pm and a CTG (cardiotocograph = foetal heart monitor) is placed on your abdomen. At 9pm, a vaginal examination is performed by the midwife and the cervix assessed. Cervadil (a strip of material containing prostaglandin) is inserted behind the cervix at this time. Generally, most women will have some contractions overnight, but this is variable.

I use the lowest dose of prostaglandin available in order to reduce the risk of hyper stimulation. Hyperstimulation can lead to very strong contractions, coming too frequently and too close together. Foetal distress can result from these severe contractions and a caesarean section may need to be done.

I will review you at 7am the next day. If the cervix is dilated, I will break your waters (ARM) to complete the induction process and facilitate the labour. This is not always necessary but can speed things up.

If you are not responding then I may leave the Cervadil in place until lunchtime. If there has been no response by that time then you are faced with a decision:

Misodel :

This agent is Misoprostol and is more effective and therefore more potent than Cervadil. I use this in first time mothers with a very unfavourable cervix. 

ARM (Artificial Rupture of Membranes):  Simply performing an ARM can be enough to stimulate labour for some women.
This is done by performing a vaginal examination and passing a small hook through the cervix. This hook then makes a hole in the membranes, "breaking the waters". Once the membranes have ruptured, the barrier to infection is gone and you are really committed to delivery.

If an ARM is performed a few hours after priming the cervix with Cervadil, it usually augments the process of induction or labour, making it more efficient.


Syntocinon:  In some situations Syntocinon will be used for induction of labour.
This is usually done by performing an ARM and then commencing an intra-venous infusion of Syntocinon. This is similar to Oxytocin, a chemical produced in normal labour that stimulates uterine contractions. The dose of the drug is gradually increased until regular contractions are occurring. This means 2-4 contractions every 10 minutes. Unlike some (but not all) spontaneous labours, your contractions will get painful fairly quickly. This may not allow you to gradually get used to the pain and is a reason why epidurals are more common with this type of induction. I guess it is a bit like Samboys, the flavour really hits you.
Syntocinon is also used to AUGMENT a labour which is progressing slowly.
Once contractions reach a satisfactory level in terms of frequency and strength, the infusion is maintained at that level until delivery.

Strip and Stretch:  A simple, minimally invasive procedure can be performed by your Obstetrician to help "move things along". This is known as "stirring the waters" or a "strip and stretch".
Using sterile gloves the Obstetrician introduces a finger through the cervix (if possible) and sweeps the membranes off the inner aspect of the cervix. This helps release the bodies own prostaglandins which can stimulate labour. It is especially effective for women who have had babies before and have a partly dilated cervix. Like all things, nothing is guaranteed. It should not be done if the placenta is low lying / praevia.

Complications:  95% of inductions will work and the woman will establish in labour. This does not mean that there will be a vaginal delivery.
Successful induction is usually dependent on a number of factors:
Sometimes it works too well and you can get foetal distress from overly strong contractions.


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