Single egg transferred IVF babies less likely to be born prematurely, underweight or stillborn

The health of artificially conceived children has steadily improved in the last 20 years with fewer babies being born prematurely or affected by low birth weight, research has shown. Researchers who analysed data from Nordic countries described the decline in premature and stillbirths as “remarkable“.

This was the main finding of a large cohort study comparing the health of babies born using assisted reproduction technology (ART), such as in vitro fertilisation (IVF), with those conceived naturally over the last 20 years.

Researchers found big improvements over time in a number of areas, including reductions in the number of miscarriages and babies born prematurely or with a low birth weight. All of these can be complications of multiple births (twins, triplets, or sometimes more).

The study looked at ART in Norway, Sweden, Denmark and Finland, and it is unclear whether we could expect to see similar improvements in the UK.

While it is likely we share similar advances in technology and improved protocols with Nordic countries, there may be other important differences as a result of eligibility for treatment.

In some Nordic countries, eligibility for reproductive treatment has been extended to include couples with less severe fertility problems. This may have accounted for some of the improvements seen over the years.

The most recent UK data from 2013 reports the ART multiple birth rate has fallen from 25% in 2008 to 16% in 2013. This would suggest a potentially similar improvement in UK outcomes for ART.

The study carried out at the University Hospital of Copenhagen found implanting one fertilised egg back into the womb reduces the chance of twins or triplets, which increase risks for the unborn babies. Where one egg was transferred babies were less likely to be born prematurely, underweight or stillborn.

Sources and more information

• Trends in perinatal health after assisted reproduction: a Nordic study from the CoNARTaS group, Oxford Journals, Hum. Reprod. (2015) doi: 10.1093/humrep/deu345, January 20, 2015. Full study PDF.
• Largest study of babies born after infertility treatment shows significant improvements in health over past 20 years,
  Oxford University Press (OUP), 19 January 2015.
• IVF babies see health improvement with fewer underweight or stillborn,
  theguardian, 21 January 2015.
• IVF babies are less likely to be born prematurely or die in infancy than 20 years ago, study reveals, DailyMail, 21 January 2015.
• Nordic IVF outcomes improving – is the same true for the UK?,
  nhs.uk/news, 21 January 2015.