Twins and multiple pregnancies
Monochorionic diamniotic twins, Monochorionic monoamniotic triplets or Higher order multiples
How common are multiple pregnancies?
Women who are pregnant with more than one baby are said to be carrying a multiple pregnancy. This happens in 1 in every 80 pregnancies and as often as 1 in every 4 pregnancies for women who have had fertility treatment. Twin pregnancies are the most common type of multiple pregnancy. Carrying more than two babies (higher order multiples) is much rarer.
Confirming your multiple pregnancy
This is usually confirmed when you have your first scan, between 10-14 weeks. Sometimes this is identified earlier if you have reasons to have an earlier scan (such as bleeding or pain). This scan helps us to find out what type of multiple pregnancy you have.
What are the types of multiple pregnancies?
When a multiple pregnancy is found, it is important to find out if the babies share a placenta (afterbirth). This is called ‘chorionicity’ and we can check this using ultrasound scanning. It is important that we know this information, so that we can plan your care during your pregnancy. Twin pregnancies or higher order multiples (triplets, quadruplets, etc.) can be monochorionic (share a placenta) or dichorionic (each have their own placenta).
What are monochorionic diamniotic twins (MCDA)?
These are identical twins which have developed from one fertilised egg. They share a placenta (monochorionic) and outer membrane (chorion) but have their own inner membrane or ‘amniotic sac’ (diamniotic). These details may be written as ‘MCDA’ in your maternity notes.
What are monochorionic monoamniotic twins (MCMA)?
These are identical twins which have developed from one fertilised egg and share the placenta (monochorionic), outer membrane and inner membrane (monoamniotic). These details may be written as ‘MCMA’ in your maternity notes.
What are higher order multiples?
These pregnancies develop from one, two or more fertilised eggs and can be a combination of chorionicities (shared or individual placenta).
How will my pregnancy be managed?
Multiple pregnancies can have more complications than a single pregnancy. For this reason you will be referred to a Consultant Obstetrician. Your care will be shared between the hospital, your Community Midwife and GP.
It is important that we closely monitor both you and your babies’ health when you are expecting more than one baby. This is known as antenatal care and will be carried out by the Fetal Medicine Team at Stoke Mandeville Hospital, from the twelfth week of your pregnancy.
We will check your blood pressure, urine and carry out general wellbeing assessments at every appointment. We will also take regular blood tests to check different levels of vitamins and minerals in your blood. You may be prescribed folate tablets (folic acid) and iron tablets to prevent iron levels in your blood from getting too low.
These checks are important, as women who are carrying more than one baby are at a higher risk of developing pre-eclampsia; a condition in pregnancy that can affect blood pressure and the kidneys.
Common problems that occur in most pregnancies can be more troublesome in multiple pregnancies; such as morning sickness, tiredness, swollen ankles, backache, pelvic girdle pain, varicose veins and anaemia. Your Midwife and GP can give you advice and support you with these common problems. They can also refer you to other professionals if required, such as the Physiotherapist.
You will have more frequent scans to check the health and growth of your babies. These will be every two weeks between 16 and 24 weeks of your pregnancy and, as a minimum at least every 3 weeks after that.
Twin to Twin Transfusion Syndrome (TTTS)
As monochorionic twins share a placenta, they also have connections in their blood circulation. This can cause a rare but serious condition known as ‘twin to twin transfusion syndrome’ or TTTS. This can develop due to uneven sharing of the blood flow between the babies. In twin to twin transfusion syndrome part of the blood flow is diverted from one twin (known as the donor) to the other twin (known as the recipient). The lack of blood supply can affect the growth of the donor twin, so they will be smaller than the other. They will also have less amniotic fluid around than normal (known as oligohydramnios).
Having a higher blood volume can make the recipient twin larger and they may have more amniotic fluid surrounding them than normal (known as polyhydramnios) which can put a strain on the baby’s heart. All monochorionic and higher order multiples will have a detailed fetal heart scan while they are in the womb, to check on how their hearts are developing.
The Fetal Medicine Obstetric Consultant will manage your care. If there are any signs of TTTS present, they will discuss the findings with you and will explain how they will monitor your babies during the rest of your pregnancy.
Signs and symptoms of TTTS
You will have regular ultrasound scans in the Fetal Medicine Unit, which will monitor the growth of your babies, the amniotic fluid levels and the blood flow. Symptoms of TTTS that you may notice are:
- Sudden weight gain
- Feeling bigger in a short space of time
- Tummy tightness
- Feeling short of breath
- Tightening across your tummy
If you experience any of these symptoms, please contact the Fetal Medicine Unit or the Maternity Assessment Unit straight away. Treatment for TTTS is available and your consultant will discuss the different options with you.
Other problems with monochorionic twins
The shared placenta may cause other problems, including slow growth. How this could affect your babies and the treatment that is available will be discussed with you by your doctor.
Labour and birth
Your Consultant will discuss with you the timing and way that you give birth to your babies. Induction of labour (when labour is started artificially) is usually offered at 36 weeks for monochorionic diamniotic twins with no complications, and between 32-34 weeks for monochorionic monoamniotic twins.
If the plan is for babies to be born early, then it may be necessary to give you a steroid injection. This helps the babies’ lungs to mature in preparation for birth and reduces the risk of breathing difficulties that can happen when babies are born early.
It is often possible to have a vaginal birth if the first baby is coming down head first. The second baby will deliver either head first or breech (bottom first). If you are expecting triplets or higher multiples you will usually be offered a Caesarean section. We may also recommend that you have a Caesarean section if there have been complications during your pregnancy.
You may go into labour naturally yourself or your waters may break. Multiple pregnancies often go into labour earlier than expected. If this happens, or you are unsure, you can contact the Labour Ward Triage (please see page 7 for contact details.)
The choice of pain relief during labour is your own. You will be given information about the different options at your antenatal classes and also by your Midwife, so you can make an informed choice. It is likely that the obstetric team looking after you will recommend that you have an epidural for pain relief. This is because twins and multiple pregnancies often require more intervention (such as forceps or Caesarean section) at the time of birth.
Whilst you are in labour, you and your babies will be watched closely to monitor both your and their wellbeing. The babies’ heart rates will be monitored using a machine that records their heartbeats and your contractions.
When you are ready to give birth you will be taken to the birthing room or the theatre on the Labour Ward. It is likely that there will be more people present for the birth than if you were having one baby. Your partner can be present and there will be at least one Midwife and the Senior Obstetricians.
There may also be a Specialist Nurse/Midwife to care for the babies, an Anaesthetist and a Paediatrician (baby doctor). However, this should not mean that you cannot give birth naturally and with privacy.
After your babies are born you will be cared for on the Labour Ward or the Observation Ward (if you have had a Caesarean section) until the Midwives feel you are well enough to be transferred to the postnatal ward. Your babies will stay with you unless they are premature or require care in the Neonatal Unit.
Most women need support and help after having a baby and are likely to need extra help when there is more than one baby to care for. Whilst you are in hospital the midwives, maternity support workers and nursery nurses will help you with feeding and general baby care. You may need to stay slightly longer in hospital if your babies are small or born before 37 weeks.
Once at home, your partner, family or friends are likely to be keen to help. This can be very useful when you are tired, need to recover from the birth and are getting used to breastfeeding more than one baby. Breastfeeding twins or more is rewarding and beneficial for both mother and babies, but it requires a little more support, help and organisation.
Your Midwife will see you regularly after you go home, to help with any questions you may have. There are also other organisations that can offer support and advice about caring for twins and multiples (see below for details).
Useful contact numbers
Stoke Mandeville Hospital
- Consultant obstetricians – 01296 316239/6548
- Labour ward – 01296 316103
- Consultant obstetricians – 01494 425009/425724
TAMBA – Twins and Multiple Births Association
Twinline: 0800 1380509 (10am-1pm and 7-10pm daily)
Multiple Births Foundation
Tel: 0208 3833519 or 0203 3133519
The National Childbirth Trust
Tel: 0300 3300772