The Leeds Teaching Hospitals NHS Trust

Leeds Maternity Care

Multiple Pregnancies Clinic

Multiple Pregnancies Clinic

Multiple pregnancies are exciting both for parents and doctors. At the same time there is no doubt that these pregnancies can carry more risks for both mother and babies. For this reason, twin (and triplet pregnancies) are managed by consultant led care in Leeds. We run a specialist multiple pregnancies clinic with care being shared with specialist multiple pregnancy midwives and consultant obstetricians with special interest in multiple pregnancy and obstetric ultrasound.

Sometimes women will be invited to participate in research, aiming to improve the outcome of multiple pregnancies. Participation in any research is always voluntary, and deciding not to take part will not negatively influence your care.

The Royal College of Obstetricians and Gynaecologists has produced an information leaflet that couples expecting twins or triplets may find a useful source of information.

Frequently Asked Questions:

Which consultants in Leeds look after multiple pregnancies?

While women may wish to deliver at either of Leeds Teaching Hospitals, we have a specialist clinic for women expecting twins or more, which is based at St James’ University Hospital. This clinic usually runs all day on Mondays.

A team of four consultants shares responsibility for the multiple pregnancies clinic. The consultants are Dr Andrew Breeze, Dr Jo Pierce, Dr Medha Rathod and Dr Mark Osmond.

If there are concerns about the development of the twins, sometimes women will be referred to the Fetal Medicine Unit, which is based at the Leeds General Infirmary/

How do I get referred to the multiple pregnancy clinic?

When you are confirmed to have a multiple pregnancy you should automatically be referred by your midwife. If this does not happen, please contact the secretaries of the consultants listed above.

When will I be seen in the multiple pregnancy clinic?

We aim to see all multiple pregnancies for the first hospital appointment between 11-14 weeks. Thereafter if your twins are non-identical you will be seen for a routine anomaly scan and then back in the multiple pregnancy clinic at approximately 24, 28, 32 and 36 weeks. If your twins are identical you will be seen more regularly in the multiple pregnancy clinic, approximately every 2 weeks. For triplets or more an individual management plan will be made at your first hospital visit.

What is the difference between identical and non-identical twins?

The majority of twin pregnancies, around 80%, are non-identical, that is they come from two eggs (released at the same time) and two sperm fertilising them. In medical terminology, these are described as ‘dizygous twins’. These twins are as similar as siblings, but importantly have their own pregnancy sacs (diamniotic) and individual placentas (medically this is called ‘dichorionic’).

The majority of twin pregnancies resulting from IVF are from two implanted embryos and are therefore non-identical.

Identical (or ‘monozygous’) twins come from one fertilised embryo. They usually share the same placenta (monochorionic), but have separate amniotic sacs. However, a proportion of monozygous twins also have their own placentas and are ‘dichorionic’. Therefore, just because twins have their own placentas does not help us to determine if they are identical or not.

Very rarely twins can be in the same sac (monoamniotic, monochorionic). As they come from the same original fertilised egg, such identical twins would be expected to be genetically identical (and therefore have to be of the same sex).

I have been told my twins are Monochorionic, why is this important? (TTTS)

There are several additional problems that may affect monochorionic twins, but the biggest of these is Twin-Twin- Transfusion Syndrome (TTTS).

Twin-twin transfusion syndrome (TTTS) is a problem with the babies’ shared placenta that can arise at any time in pregnancy but most commonly between 16- 22 weeks.

It only affects monochorionic twins and occurs in about 10-15% of such pregnancies. Usually there are blood vessels that run backwards and forwards between the two halves of the twins’ shared placenta and each baby receives the same amount of blood from you. In TTTS there are blood vessels in the placenta that shunt blood from one twin, the donor, to the other, the recipient. As a result, the donor twin receives too little blood from the shared placenta. They are usually smaller than the other twin. The donor twin does not produce as much urine as normal, so the amount of fluid in their gestational sac is low. This can be measured on ultrasound scan and is called oligohydramnios.

Conversely the recipient twin receives too much blood from the shared placenta. They are usually larger than the other twin and the extra blood may put an additional strain on their developing heart. The recipient twin produces more urine than normal, so the amount of fluid in their gestational sac is high. This is called polyhydramnios. You yourself may feel breathless and uncomfortable with a swollen tummy due to this extra fluid. More seriously, the extra fluid increases the pressure on the opening of the womb, the cervix. This extra pressure can cause early contractions and premature labour.

TTTS is detected by ultrasound scan. Assessment of the twins’ overall sizes, their bladder sizes, the volume of fluid around each one and blood-flow studies or ‘Dopplers’ are checked at each scan. The severity of TTTS ranges from mild to severe. Mild TTTS does not necessarily require treatment and can be monitored by ultrasound scanning in Leeds. It may resolve spontaneously. More severe TTTS requires treatment. For this you may need to be referred to a specialist clinic outside of Leeds.

TTTS can be a serious condition and untreated can result in the loss of one or both babies.

If you would like more information about TTTS please visit the Twin-Twin Transfusion Syndrome Foundation website at

Will I be treated differently if this is an IVF pregnancy?

No, once we have determined the chorionicity of your twins we have shown that IVF twins have similar outcomes as twins arising spontaneously, and you will therefore be treated with the same care.

What about antenatal screening for Down's Syndrome?

For women who are seen early enough in the pregnancy, we offer combined screening for Down syndrome using nuchal translucency and maternal blood tests. This ultrasound based test can only be performed between 11 weeks and 13+6 weeks so if referral occurs after this time it will not be possible.

Will my twins or triplets be born early?

Full term for twins is considered to be 37-38 weeks and this is when you will ideally deliver your babies. Some twins will deliver before this and depending on when this occurs depends on how significant it is. Around a half of twin pregnancies will deliver at or before 36 weeks either because labour starts early or because of complications that lead to a recommendation of an earlier birth – either for the mother’s health reasons or for those of one of both twins.

The birth of triplets is usually planned at around 34-35 weeks, but again this may happen earlier if there are complications during the pregnancy or labour starts prematurely.

If you go into premature labour attempts may be made to stop labour, but if this is not possible the babies will need extra care on the neonatal unit (NNU). Unfortunately, it is not always possible for the SCBU to accommodate all preterm babies and there is a chance that you and the babies will need to be transferred to another unit elsewhere in the region or even in the country to ensure they get the best available care.

If you experience intermittent or constant abdominal pain, bleeding from your vagina, loss of fluid from your vagina or reduced movements of your babies, please ring the Maternity Assessment Centre at the hospital where you are planning the birth of your babies:

Leeds General Infirmary                0113 3926731  or

St James's University Hospital         0113 2065781

How will my twins be born?

For women with a twin pregnancy, the way you give birth to your babies will depend on the position of the first baby closest to the cervix (or opening of the womb), if the babies are to be born prematurely, if the woman or her babies have any health complications, as well as your own preferences.

Essentially the process involved, whether a Caesarean or vaginal birth, will be very much the same as for women having single babies, but there are some aspects that can vary.

Vaginal birth or Caesarean Section?

The decision to plan a vaginal birth or have an elective Caesarean section is often based on the same reasons for women having a single baby. These can include health complications such as the woman having very high blood pressure, placenta praevia or placental abruption, concerns about the wellbeing of the baby or babies before or during labour, problems with the labour not progressing, an unsuccessful induction or an increased risk of a cord prolapse. Twins that are very premature may be more likely to be delivered by Caesarean section.

Factors influencing the decision of how a woman with twins gives birth tend to centre around whether the first twin (the baby lying closest to the cervix) is in a head down position and what position the other baby is in.
Vaginal birth for twins is possible, but a less common occurrence when compared to women having only one baby. In the Multiple pregnancy clinic in Leeds the Caesarean rate for twins is ~50% (about twice the rate for single babies at 20%)

However, if there are no major complications, the first baby is lying in a head down position, you are keen to have a natural birth and your caregiver is supportive, it is good to know that it is achievable. Around 50% of twins are born at term (often around 37 to 39 weeks); the other 50% are born prematurely (before 37 weeks).

The first baby born vaginally is the one situated closest to your cervix and is referred to as Twin 1; the second baby born is called Twin 2. If you have a Caesarean the babies will be born in whatever order is most convenient for the doctor. So Twin 1 may not necessarily be the baby that was lying closest to your cervix and they may not be born in the order you labelled them with ultrasound before birth.

As well as the RCOG information leaflet, there is further information on multiple pregnancies available from the NHS websites, TAMBA (the Twins and Multiple Births Association) and NICE (National Institute for Health and Care Excellence):


NHS information on multiple pregnancy:

NICE information on Multiple Pregnancy: