Twins & Triplets

I have been diagnosed with twins – what does this mean for my pregnancy?

Approximately 1-2% of pregnant women carry twins, although this figure is increasing with the widespread use of assisted reproductive technologies. Any pregnancy where there are two babies is naturally more complicated than where there is only one. Unfortunately, all the common symptoms of pregnancy are more pronounced in women carrying twins including morning sickness, constipation, tiredness, anaemia, varicose veins and back pain.

In addition, some serious pregnancy complications are more common with twins:

  • Miscarriage
  • Premature delivery
  • Pre-eclampsia / high blood pressure
  • Gestational diabetes
  • Fetal growth problems

Dr. Colin Walsh is very experienced in caring for twins. He offers complete private care of your twin pregnancy, including antenatal care, all ultrasound scans, labour and delivery and post-natal follow-up. Colin has cared for hundreds of twin and triplet pregnancies. He has cared for complex monochorionic (identical) twins, has diagnosed and managed twin-twin transfusion syndrome and has personally performed hundreds of ultrasound scans in twin and triplet pregnancies. He is very experienced in both vaginal twin delivery and caesarean section and has published several papers on twins in international scientific journals.

Twins & Triplets

I don’t fully understand the different types of twin pregnancy. Can you explain them?

Twin pregnancies are classified according to the number of placentas (chorionicity) and the number of sacs (amnionicity). This is determined by ultrasound scan and is most accurately assessed in the 1st trimester. In general terms, the more structures the twins share, the higher the risk:

  • Dichorionic-Diamniotic (DCDA twins) are the commonest type (80% of twins). Each twin has his/her own sac and his/her own placenta. Most dichorionic twins will be “non-identical”, that is the result of 2 eggs being fertilised.
  • Monochorionic-Diamniotic (MCDA twins) are the second most common type (20% of twins). The twins share a single placenta but each have their own sac. These twins are always “identical” and will be the same gender.
  • Monochorionic-Monoamniotic (MCMA twins) are very rare (<1% of all twins). These identical twins share both the placenta and the same amniotic sac.

My twins are sharing a placenta – what risks does this pose?

Approximately 20% of twins share a single placenta (monochorionic). These twins are always identical. In addition to the risks for any twin pregnancy listed above, MC twins also have an added 10-15% risk of twin-twin transfusion syndrome (TTTS). TTTS is a very serious condition, in which the placenta is not shared equally by the twins (leading to one twin receiving too much blood supply and the other not enough). This condition is diagnosed by ultrasound scan after 16 weeks. We are very experienced in caring for couples expecting twins, have performed ultrasound surveillance for hundreds of monochorionic twin pregnancies and have diagnosed and treated TTTS.

What about triplets?

A triplet pregnancy is a rare event whereby the woman falls pregnant with 3 babies. Naturally-occurring triplet pregnancies happen only in approximately 1-in-6000 pregnancies. Most triplet pregnancies these days are as a result of fertility treatment. Higher-order multiple pregnancies, such as quadruplets (4 babies) or quintuplets (5 babies) are even less common.

What implications do triplets have for my pregnancy?

As with a twin pregnancy, the main determinant of risk in triplets is the number of shared placentas (chorionicity). In most triplet pregnancies, there are 3 placentas and 3 sacs – one for each triplet (trichorionic triplets). In the remaining triplets, the placenta is shared – usually there is a pair of identical twins (with one shared placenta) and a singleton (with another placenta), called dichorionic triplets. Triplet pregnancies where all 3 triplets share a single placenta are very rare.

A triplet pregnancy is considered very high risk of complications and you should be cared for by a fetal medicine specialist with experience in complex multiple pregnancy. Triplets should be delivered by caesarean section by 34 weeks gestation. The team at SHORE FOR WOMEN are experienced in providing antenatal care and performing ultrasound scans in triplet pregnancies.

Other High-risk Pregnancy Lists

  • Mater Hospital
  • North Shore Private Hospital
  • The University Of Sydney
  • Royal College Of Obstetricians and Gynaecologists