Risks to the child

Many people think ‘What could be better than completing your family in one go, with twins or even more babies?’ After all, most of us know normal, healthy twins, or read the heart-warming newspaper stories of families who are delighted with their quads, quins, or even more babies, following IVF.

Sadly, this is not the whole picture – the reality is that for many twins and triplets, life can be fragile and difficult.

Why are twins and triplets at greater risk of problems?

The health risks for twins and triplets are significantly higher compared with those for singletons, mostly because multiple babies tend to be born prematurely and underweight. The risk of early and late miscarriage is also higher for twins than for singleton pregnancies.

The chance of a single embryo dividing and resulting in identical twins is higher after IVF though it is not yet known why this happens. So it is possible to end up with identical twins from a single transferred embryo, or triplets from two embryos.

The majority of these identical babies share a placenta and are at even higher risk from complications during pregnancy than non-identical twins, such as twin-to-twin transfusion syndrome, which can cause serious health problems and death.

If a multiple pregnancy is thought to be a serious health threat to mother or babies, the clinician may suggest a fetal reduction to improve the chances of survival and healthy outcome for the remaining fetus(es), whilst reducing the chance of losing the pregnancy altogether. For more information contact the Multiple Birth Foundation at mbf@imperial.nhs.uk

The expert says...

Jane Denton"The aim of all infertility treatment should be to have one live, healthy baby. The anguish of watching one or more of your children die or living with a severe disability is a situation no parent would wish to face, yet it is a frequent consequence of multiple births that is so often underestimated."

Ms Jane Denton, Director of the Multiple Births Foundation

Premature birth – the facts

Many twins and triplets are born prematurely, meaning that these babies are born before the normal time for healthy singleton babies:

  • Singleton babies are usually born at around 40 weeks of pregnancy, and tend to have normal birth weights.
  • At least half of twins are born before 37 weeks, with low birth weights, making them at high risk of serious health problems and death. Many are born before 35 weeks, when they often need neonatal care. Their birth weight is around 800–1000g less than singletons.
  • Over 90% of triplets are born before 37 weeks and many are born so early that they have a greater risk of long-lasting, serious health problems or may die soon after birth.

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The expert says...

Jane Denton"Although there are many joys for these [multiple birth] families, far less well known are the higher risks for the mothers and babies. Prematurity and low birth weight are the main reason for increased mortality and disability for these children."

Ms Jane Denton, Director of the Multiple Births Foundation

What are the common problems with premature births?

Prematurity can cause many problems and may even result in the death of the baby. The problems caused by prematurity can range from those that affect only the early stages of the child’s life to those that have a devastating and lifelong impact.

Early stage problems

  • Between 40–60% of IVF twins need to be transferred to the neonatal care unit when they are born. By comparison, only 20% of singleton IVF babies need the same level of care.
  • 8% of twins need help with their breathing and 6% suffer from respiratory distress syndrome (breathing difficulties) compared with 1.5% and 0.8% for singletons respectively.
  • The overall risk of death during birth or the first year of life is higher for twins than for singletons.
  • The risk of death around the time of birth is three to six times higher for twins and nine times higher for triplets. A study from 2003 estimated that if all IVF babies born in the UK had been singletons, the deaths of 126 babies could have been avoided.

Longer term health and development problems

  • A small percentage of twins have severe health problems that will affect their entire lives (for example cerebral palsy, which affects between four and six times as many twins compared with singleton babies).
  • Prematurity and low birth weight carry the risk of lower IQ and are linked with Attention Deficit Hyperactivity Disorder (ADHD) and long-lasting behavioural difficulties.
  • Problems with language development are more common in twins. Twice as many twins need speech therapy compared to singletons.
  • According to a Japanese study, in 7.4% of twin pregnancies, at least one child had a disability, such as cerebral palsy, impaired sight, or congenital heart disease. For more information see Research.

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Have you had or begun IVF treatment recently?

The HFEA want to hear your views on single embryo transfer.

Your feedback will help them develop their approach to the risk of multiple births from fertility treatment.

  • What did your clinic discuss with you?
  • How did you decide on the number of embryos to transfer?

Let them know in this patient questionnaire