Drugs Used to Contract the Uterus During Third Stage
These are also called uterotonic drugs or sometimes oxytocic drugs as they act in a similar way to the hormone oxytocin which naturally contracts the uterus. Use of these drugs for preventing and managing postpartum haemorrhage (PPH) varies widely between the different countries in Europe, including the type of drug and the timing of its use.
Oxytocin (Trade names: syntocinon, pitocin)
This is the most commonly used drug for active management of third stage in Europe. It is a synthetic form of the hormone oxytocin which is produced naturally during labour, after the birth when the placenta is being delivered, and when the baby is being breastfed. It makes the muscle of the uterus contract strongly. It can be given as an intramuscular injection, intravenous injection or by intravenous infusion (drip).
Research evidence shows that it reduces PPH (measured as both 500ml blood loss or 1000ml blood loss). The European Consensus on Prevention and Management of Postpartum Haemorrhage recommends this as the drug of first choice for management of the third stage of labour. The usual dosage is 5 or 10 International Units.
Ergometrine (an ergot alkaloid)
This drug produces intense contractions of the uterus which close the blood vessels at the site of the placenta. It can be given on its own to women at high risk of PPH, following administration of oxytocin and the delivery of the placenta. When given intravenously it works within a minute and is extremely effective at stopping bleeding but may cause side effects such as retained placenta, nausea, vomiting and high blood pressure.
Syntometrine® (combination of syntocinon and ergometrine)
This has been shown to be more effective at preventing postpartum haemorrhage than using oxytocin (syntocinon) alone but is associated with more nausea, vomiting and high blood pressure. It is widely used in the UK and in Ireland but should not be used in women with high blood pressure.
The dosage is 5 IU oxytocin with 500 micrograms of ergometrine in a single 1 ml ampoule. Syntometrine® is not licensed for use in many European countries.
Misoprostol (a prostaglandin)
Misoprostol has been found to be less effective at preventing PPH than the uterotonics discussed above and has more side effects. However it has the advantage that it can be given by mouth and does not need to be refrigerated so it can used in circumstances when it is not possible to store or inject other uterotonic drugs.