Multiple pregnancies are less likely to go to full-term (40 weeks) than single pregnancies. Twin births may take place at 37 weeks, triplets at 34 weeks.
In a 2008 Tamba survey, only 43% of twin pregnancies and 1.5% of triplet pregnancies lasted more than 37 weeks.
In the UK, more than half of twin babies are born by Caesarean section, so familiarise yourself with the procedures. See our birth section for information. You are most likely to have a C-section if you are expecting triplets or quads.
It is rare but possible that you may manage to deliver the first twin vaginally but the second twin may get into distress and need to be delivered by Caesarean.
It is standard practice to monitor your babies during a multiple delivery. A fetal heart monitor will be strapped round your abdomen to assess your babies' heartbeats and the intensity and frequency of your contractions.
Monitors can be bulky but you should still be able to move into different positions with the help of your midwife.
If the external monitors are not able to pick up your babies' heartbeats accurately, the first baby will be monitored internally via a fetal scalp electrode attached to the baby's scalp.
You may be advised to have an epidural due to the higher risk of intervention during a multiple birth. Discuss this in advance with your midwife and medical team.
When you give birth, your birth team is likely to include an obstetrician, an anaesthetist, two midwives, one paediatrician per baby, plus students or junior staff.
If you feel you do not want lots of people present, you can ask for all non-essential staff to wait outside the room until they are needed.
You may be encouraged to give birth on your back, but with the support of your midwives, it may be possible to deliver twins safely while standing, squatting or on all fours.
After the first baby is born, doctors will feel the position of the second twin and if necessary attempt to manually move it into a vertex (head down) position. This can sometimes be done externally, but it may be necessary to do a breech extraction (pull baby out by the feet) or to turn the baby internally. This requires pain relief if you haven't already had it.
Your babies may be born one after the other in the space of a few minutes and are usually both delivered within 20 minutes of each other.
While the second baby is being delivered, your birth partner can put the first twin onto their chest (under their shirt) for warmth and bonding.
After the babies have been delivered, you enter the third stage of labour - delivery of the placenta. Natural delivery of the placenta is generally not recommended with a multiple birth because of the increased risk of bleeding with a larger placenta. An injection of Syntometrine will contract the uterus and expel the placenta.
You should be prepared for the fact that your babies may spend some time in neonatal care. In the 2008 Tamba survey, 44% of mums of twins said at least one of their babies had spent time in neonatal intensive care.
This figure rose to 91% for mothers of triplets.
More than half of all twin babies and 99% of triplets weighed below 5lb 8oz at birth.
Remember though, that studies show premature multiples mature more quickly than single babies born at a similar time, and multiples are often better equipped for early starts. Visit our premature and special care baby section for advice about looking after early babies.
See tamba.org.uk for more information, and to download Tamba's free Healthy Multiple Pregnancy Guide for everything you need to know about multiple pregnancies.