Most women carrying twins, triplets or more will go on to have healthy babies

Women pregnant with twins, triplets or more are often alarmed to find themselves automatically placed in a ‘high-risk’ category. In fact, most women carrying twins, triplets or more will go on to have uneventful pregnancies and healthy babies.

However, there are conditions that can arise in any pregnancy, such as anaemia, preeclampsia or gestational diabetes, which are more common in multiple pregnancies and are therefore worth watching out for.

There are also some complications that arise only in twin, triplet or more pregnancies. These are rare, but when they happen they do need medical attention and monitoring.

Fortunately, much more is known about these rare conditions than was once the case, and the medical expertise now available is outstanding – as parents of twins, triplets or more who have dealt with such problems can testify.

A woman pregnant with twins, triplets or more


What to look out for in a multiple pregnancy

If you are concerned about any of the issues listed below, talk to your doctor or midwife. 

Here’s a brief list of what to watch out for.

This is a rare complication that only affects twins who share a placenta (Monochorionic). In TTTS, a blood transfusion occurs from one twin (the ‘donor’) to the other (the ‘recipient’). The donor twin becomes smaller and may suffer anaemia, while the recipient twin is put under strain. Often the donor twin also has less amniotic fluid but the recipient has lots, which can cause the mother’s belly to become larger than would be expected. If TTTS is diagnosed, your pregnancy will be closely monitored by frequent ultrasounds to check on the babies’ growth. If necessary, you may be offered laser ablation therapy to separate the blood vessels in the placenta. Twins Trust has developed a range of TTTS resources including personal experiences to provide you with more information on the condition.

Although monochorionic monoamniotic twin and triplet pregnancies are very rare, they have a high risk of adverse pregnancy outcomes (MCMA pregnancies occur in about 1 in 10,000 pregnancies overall and triplet pregnancies occur in about 3 per 10,000 pregnancies).

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What is TTTS?
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TTTS and treatment options

Twin Anaemia-Polycythaemia Sequence (TAPS) is a rare complication that is specific to monochorionic pregnancies (babies who share a placenta) and occurs in 3-5 percent of these pregnancies.

Small blood vessels can form in the placenta between the babies, connecting their blood supplies, allowing a slow passage of blood from one baby to the other. This can cause the baby donating the blood (donor) to become anaemic (low blood levels), and the baby receiving the blood (recipient) to become polycythaemic (high blood levels), which can lead to overload and strain on the heart.

Most twins and triplets grow normally in the womb, although they do tend to be a little smaller than singleton babies.  In all pregnancies however, there is a risk that the placenta(s) will not keep pace with the needs of the growing baby and this can cause their growth to slow down.  This can put the baby, or babies, at risk if it goes unrecognised. Fetal growth restriction is more common in twin pregnancies and even more so in triplets and higher order multiples.  Regular ultrasound scans will be offered to you to monitor the growth of your unborn babies.  Premature delivery is sometimes recommended if one or more of your babies is very small. Find out more about growth restriction.

Fighting with Selective Intrauterine Growth Restriction
Born prematurely in July 2021, twins Chester and Otis met outside the womb for the first time in September.

Twin Reversed Arterial Perfusion sequence (TRAPs) is a very rare complication that is specific to monochorionic pregnancies (babies who share a placenta) and occurs in roughly 1 percent of these pregnancies.

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Multiple pregnancies and potential issues

Our Complications Guide is designed to help you to understand some of the conditions associated with twin, triplet and higher-order pregnancies. Although these complications are rare, we hope the information in this booklet will help you understand what to expect if you are diagnosed with any of these conditions.

We are researching and campaigning for better care for families with multiples

Over recent years, Twins Trust has followed a strategy of undertaking, commissioning and encouraging research so we can better understand our families’ experiences with twins, triplets or more. The findings from our research can be found in our recent reports. This research has enabled us to campaign to seek improvements in the care families’ receive. 

Twins Trust will be commissioning further research over the coming years to help improve the care for parents with pregnancy complications, such as MCMA pregnancies and Twin to Twin Transfusion Syndrome. Keep an eye on our website and social media channels for updates.

Bereavement support

Sadly there will be some rare circumstances in which one or more multiple pass away. If this has happened to you, our Bereavement Team is here to support you.

Our Early Pregnancy Workshop is aimed at pregnant women and their partners before 20 weeks. Get your questions answered in a friendly, non-judgmental environment.