If you’re pregnant with more than one baby (a multiple pregnancy), a healthy lifestyle and diet will help you cope with your pregnancy and give your babies the best start in life.
The advice for keeping healthy in pregnancy is similar whether you’re expecting twins, triplets or just one baby. Eat well, take gentle exercise, drink lots of fluid and, if you feel stressed, get support from friends and family or talk to your midwife.
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Very little research has been done on nutrition during multiple pregnancy, so the best advice is to eat a balanced, healthy diet. If you feel hungry, fill up on healthy snacks, such as fresh fruit, low-fat yoghurt or sandwiches filled with grated cheese, lean ham or mashed tuna. Expecting two babies doesn’t mean you have to eat significantly more than during a single pregnancy.
You may be offered iron supplements during your pregnancy as you're more at risk from anaemia during a twin pregnancy. Discuss this with your midwife or doctor.
The Twins & Multiple Births Association (Tamba) has produced The Healthy Multiple Pregnancy Guide, which should be given to all women expecting twins or more by their antenatal care team. If you register with Tamba on their website, you can also download it for free.
The guide provides in-depth information on multiple pregnancies, including common health problems, complications, keeping healthy, rights and benefits, preparing for the birth and the birth itself.
What antenatal care can I expect with twins?
Because there are increased risks associated with a multiple pregnancy, especially if your babies share a single placenta, good antenatal care is essential.
It's important to attend the ultrasound scan you will be offered between 8 and 14 weeks. This is the best time to determine the type of placenta and membranes your twins have (chorionicity), check your dates and have a nuchal translucency test for Down’s syndrome done. A scan to check for structural abnormalities will be performed around 18-22 weeks. Find out more about screening for Down's syndrome.
The number of check-ups and scans you will be offered will depend on the type of twins or multiples you're having.
Types of twins
There are three types of twins. The biological principles are the same for triplets, though these are more complex than with twin pregnancy. The three types of twins are:
- dichorionic diamniotic (DCDA) twins: each has their own separate placenta with its own separate inner membrane (the amnion) and outer membrane (the chorion)
- monochorionic diamniotic (MCDA) twins: share a single placenta with a single outer membrane and two inner membranes
- monochorionic monoamniotic (MCMA) twins: share both the inner and outer membranes
All non-identical twins are DCDA, and one-third of identical twins are DCDA. The other two-thirds of identical twins are MCDA, and just 1% of identical twins are MCMA.
The percentages of identical and non-identical twins born in the UK are not routinely recorded but, according to the Multiple Births Foundation, around one-third of twins are identical.
What extra care can I expect with twins?
If your babies are monochorionic diamniotic (MCDA), you can expect more scans and monitoring as these types of twins have the highest risk of Twin-Twin Transfusion Syndrome (TTTS), an abnormality of the placenta. The scans are usually every two weeks from 16 weeks, and you may be referred to your regional hospital with a centre for foetal care to be seen by a specialist doctor.
If your babies are monochorionic monoamniotic (MCMA), you will also have frequent scans, as with these types of twins there is often some cord entanglement, which can cause complications. These types of twins are rare and so you can expect to receive specialist care and close monitoring. You should be seen by a foetal medicine specialist who has cared for these types of twins before. At the moment, the usual practice is an elective delivery at 32-33 weeks pregnant.
If your babies are dichorionic diamniotic (DCDA), the risks to their health in the womb are much lower. You will usually be scanned every four weeks.
It's important to attend all your appointments as this will allow any problems to be picked up early and treatment to be offered where necessary. You can find out more about antenatal checks and tests.
Risks to you in a multiple pregnancy
While most multiple pregnancies are healthy and result in healthy babies, there are more risks to be aware of when you are pregnant with two or more babies. Make sure you go to all your antenatal appointments so that any problems can be picked up early and treated appropriately.
If you're pregnant with more than one baby, you're at higher risk from all the complications associated with pregnancy and birth:
Risks for multiple babies
- half of all twins are born prematurely (before 37 weeks) and have a low birthweight of under 2.5kg (5.5lb); triplets have a 90% chance of being born prematurely and of having a low birthweight
- the risk of death for premature babies around the week of birth is five times higher for twins and nine times higher for triplets than single babies
- identical twins have a higher risk of congenital abnormalities (birth defects)
- twins are four times and triplets 18 times more likely to have cerebral palsy than single babies
Twin-Twin Transfusion Syndrome
Twin-Twin Transfusion Syndrome (TTTS) affects identical twins who share a placenta (monochorionic). The risk is higher for MCDA twins, but it can occur in MCMA twins too. It is caused by abnormal connecting blood vessels in the twins’ placenta. This results in an imbalanced blood flow from one twin to the other, leaving one baby with a greater blood volume than the other.
TTTS affects 10-15% of monochorionic pregnancies and if undetected carries a higher risk of foetal death. Treatment for TTTS varies and is determined by many factors. It's important to discuss it with your consultant, as what works in one TTTS pregnancy may not be appropriate in another. For more information on TTTS, see the Twin2Twin website.