Multiple Pregnancy (Twins or more)

TwinsFollowing your first scan, you are likely to be experiencing many emotions after having this news that you are expecting more than one baby.

A multiple pregnancy is more complicated than a single pregnancy. These include slow growth of one or both babies, blood pressure problems and premature labour. For these reasons it is recommended that you are seen regularly at the hospital antenatal clinic and are under the care of an obstetrician (Doctor who specialises in pregnancy and birth). You should still arrange to see your community midwife between any hospital visits.

There are two ways that twins are formed:

Non-Identical Twins (dizygotic twins) - two eggs are fertilised by two sperm. This occurs in 2/3rd of twins. There are always two placentae (afterbirths) and two amniotic sacs (membrane bags surrounding baby) (dichorionic, diamniotic).

Identical Twins (monozygotic twins) -  only one egg is fertilised by one sperm. The egg splits and develops into two babies. How soon the split happens will determine whether there is one placenta (monochorionic) or two (dichorionic), and whether there is one sac around the babies (monoamniotic) or two sacs (diamniotic).

Triplets and above can occur in a combination of the above.

What care can I expect during pregnancy?

You should agree an individual plan of care with your obstetrician taking into account any other factors which may be present, such as any previous pregnancy or problems at birth and any other identified problems.

Multiple pregnancy puts more demand on the mother during pregnancy, so you should take iron and folic acid throughout pregnancy to avoid anaemia which can be bought at most pharmacies or supermarkets.

Twins
Your scan at 11-14 weeks will help us determine how often we will need to see you, and this will depend mainly on whether there is one or two placentae (chorionicity).

If you wish to have screening for Down’s Syndrome (along with two other relatively common chromosome problems, Edward’s and Patau syndrome) this can be done with combined screening of blood tests and an early scan by performing a nuchal  translucency test (measuring the thickness of the back of the babies’ necks).

You need to consider carefully whether to have this done, because there is a chance that only one baby may be affected.

Dichorionic twins
You will be offered a scan at 20 weeks to check your babies are developing normally (anomaly scan).

Monthly growth scans (e.g. 24, 28, 32, 36 weeks of pregnancy) of the babies will be arranged, and then reviewed in the hospital clinic. Growth of twins can be slower than expected in about 25% of dichorionic twin pregnancies. If we find that one or both of your babies are growing slowly, we may offer an increased number of scans.

Your blood pressure and urine should be checked at every antenatal visit (e.g. 10-12, 20, 24, 28 and then every two weeks), because women expecting twins have a higher chance of developing high blood pressure and pre-eclampsia.

By 32 weeks the obstetrician will discuss with you the options for the birth of your babies. If you are having dichorionic twins, complications affecting the well-being of one of the twins can occur towards the end of the pregnancy, therefore we recommend that birth is planned around 37- 38 weeks to reduce the risk.

A planned birth is either by induction of labour (starting labour with a special hormone pessary inserted into the birth canal) or by a Caesarean birth. A Caesarean birth is usually planned after 37-38 weeks as babies born by Caesarean section earlier than this have a higher risk of breathing difficulties.

Monochorionic twins
When twins have the same placenta a condition called twin-to- twin transfusion syndrome (TTTS) sometimes develops. This happens because blood vessels in the placenta can be joined, so that blood can flow from one baby to the other. This can affect the growth and well-being of the babies, with one becoming very small compared with the other. This condition may be picked up early on in pregnancy, so from 16 weeks you will have a scan every two weeks. If this condition is detected a plan will be carefully discussed with you, and may include being referred to be seen in the regional fetal medicine unit at St Michael’s Maternity Unit, Bristol.

Your scan at 20-22 weeks is to check that there are no abnormalities. 

Growth scans will be arranged every 2 weeks, as growth of twins can be slower than expected. If we find that one or both of the babies are growing slowly, we may increase the number of scans that you have.

As with dichorionic twins, your blood pressure and urine should be checked at every antenatal visit. By 32 weeks the obstetrician will discuss with you options for the birth of your babies. You will usually be offered an option for a planned birth of your monochorionic twins at 36 – 37 weeks because complications affecting the well-being of one of the twins can occur towards the end of pregnancy. We may recommend a Caesarean birth, especially if the twins are monoamniotic (in one sac).

Triplets (or more)
A triplet pregnancy has a higher risk of complications than a single or twin pregnancy. An individual plan of care should be discussed and agreed with you. You will be seen by a fetal medicine consultant. You will have frequent scans (at least every 2 weeks), to check the growth and well-being of your babies. You may need to attend the regional fetal medicine unit at St. Michaels Maternity Unit, Bristol.
Birth is usually planned when you are 34-35 weeks and is by Caesarean birth.

What can I expect during labour and birth when expecting twins or more?

If your pregnancy has been straightforward, the position of the babies in the womb is very important and the obstetrician will consider this in discussing with you the safest options to offer you for the birth of your babies.

Continuous heart monitoring - when you are in labour we recommend continuous fetal heart monitoring. Sometimes it can be difficult to clearly monitor both babies hearts, so we often need to use an internal lead (fetal scalp electrode, FSE) which is
applied to the head of twin one during a vaginal examination, and an external lead for twin two. This should be continued until twin two is born.

Pain relief -we expect that labour with twins will progress at a similar rate to labour with a single baby and most options for pain relief can be considered. However, if you wish to consider using an epidural, it can be useful, especially if your second baby is not head down. After the first baby is born, we may need to help
twin two to move into a suitable position to be born. Sometimes this may involve an internal examination, which is easier and more  comfortable for you with good pain relief.

Giving birth to the second baby - the second twin may be born either cephalic or breech. After the first baby is born, a drip (with Syntocinon) is often used to help contractions restart. You are likely to have an ultrasound scan to check the position of the second baby. We sometimes need to help twin two move into a suitable position either repositioning your baby through your tummy, by pressing to move your baby, or by doing an internal examination. We usually expect that the second baby is born within about 40 minutes of the first.

Infrequently the second twin may need to be born by Caesarean Section.

Afterbirth Bleeding - is more likely following twins because the womb has been stretched more than with a single baby. Having Syntometrine or Syntocinon (an injection to contract your womb and assist the delivery of the placenta) and a Syntocinon infusion (drip) after the birth reduces this risk.

Preterm labour -the average gestation (length of pregnancy) with twins is 36 weeks. If you think you are in labour, you should come in to hospital to be assessed. If the babies are unlikely to be born immediately, we are likely to give you two steroid injections. These help mature your babies’ lungs and may reduce the chance of the babies developing breathing problems.

Breastfeeding - many parents are unsure whether it is possible to breastfeed more than one baby. However there are many who do. Breastmilk is designed to be produced by supply and demand so whether feeding one, two or more babies, mums will produce enough breastmilk for their babies’ needs provided the babies continue to breastfeed.

Support with breastfeeding is available from your midwife and health visitor.

For more information visit www.nhs.uk/conditions/pregnancy-and-baby/pages/twins-healthy-multiple-pr...