Pregnancy health centre

Twin pregnancy

How common are multiple births?

Discovering that you're having twins can be a shock, and it may mean that your pregnancy is slightly different to what you expected. Here's what you need to know.

How common are multiple births?

Twins and multiple births have become increasingly common over the years and now 1 in every 65 pregnancies results in more than one baby.

This rise is largely down to the introduction of IVF, when more than one embryo is often implanted. One in four IVF pregnancies results in twins.

Not all twins are identical. The odds of having identical twins is around 1 in 250.

Finding out

Most women discover that they're carrying more than one baby during an ultrasound scan. But it is possible to guess that this is the case beforehand. Mums-to-be with twin pregnancies sometimes have more severe morning sickness, start to grow a bump more quickly and feel very tired in the first few months.

Even if you choose not to have an ultrasound and you are carrying twins, it will be picked up in other ways. The midwife will hear two foetal heartbeats when she examines you, or may spot that your bump is particularly large for the stage of pregnancy you're at.

How is a multiple pregnancy different from a single one?

There are several ways in which a multiple pregnancy may differ. Here are the main ones:

• Twin pregnancies tend to last for around 37 weeks, rather than 40 weeks.
• You will go for more scans and antenatal appointments during your pregnancy to ensure that both babies are developing well.
• You will also be checked for signs of pre-eclampsia and high blood pressure at these appointments, as they are more common in multiple pregnancies.
• Greater weight gain - you not only have an extra baby to carry, but also extra amniotic fluid and an extra placenta (if the twins are non-identical).

Giving birth

How you give birth to your babies will probably be determined by what position they are in. About 40% of twins are both head-down, which means it should be fine to have them vaginally. Another 30% of mums have the first twin head-down and the second twin breech, and this position also makes a vaginal birth possible.

If both babies are breech, or if the first baby is breech and the second head-down, they will probably be delivered by Caesarean.

If you are able to have a vaginal delivery, although you are having two babies, you will only have to go through labour once. Each baby will have its own pushing stage, but you will only have one first stage of labour and contractions.

Sometimes - in around 3-4% of multiple births - the first twin will be born vaginally and the second by Caesarean. This usually happens because of complications with the second baby - it may have changed position or complications may have arisen with the birth of the first baby.

Getting support

Finding out you are expecting twins can be exciting, happy, but may also come as a shock. It's quite normal to feel a little daunted, so make sure you get all the help and advice you can.

As multiple births are now more common, it's likely that you'll know, or know of, someone who has twins or triplets. Get in touch with them and ask any questions you may have. They'll be an invaluable source of help and support throughout your pregnancy and after your babies are born.

There are also various support groups for mums-to-be of multiples.