IVF births using frozen embryos will be compared to births from 'fresh' embryos in a large-scale multi-centre trial which is the first-of-its-kind in the UK and led by a team from the University of Aberdeen in collaboration with the NPEU Clinical Trials Unit, University of Oxford.
Researchers want to see which method produces the greater number of healthy* babies, as well as considering the health of the mother and costs to the health service and longer-term to society.
1,086 couples will be recruited for the Randomised Controlled Trial (RCT), funded by £1.41m from the Health Technology Assessment (HTA) Programme. This is the first IVF trial ever funded by the body.
Principal Investigator Dr Abha Maheshwari made headlines in 2012 when she published a paper calling for a debate into whether freezing embryos is healthier for mother and baby than using fresh embryos.
Previously it was argued that using frozen embryos could result in fewer births but current research has found that using frozen embryos can lead to a lower chance of haemorrhage, premature birth and deaths in the first few weeks of life.
Participating couples will be randomly split into two groups – the ‘fresh’ group will have their embryos created and transferred in the same week, whilst the ‘frozen’ group will have the transfer completed sometime within three months of embryo creation.
In the context of the trial, a ‘healthy’ birth will be considered to be one baby delivered after 37 weeks, within normal weight parameters.
Each patient will be treated according to their own individual clinical needs and national guidelines will be followed. The only intervention will be regarding delayed or immediate embryo transfer.
Dr Masheshwari said: “Since our 2012 paper, support for our view that frozen embryos can lead to better, or at least equal results to using fresh embryos has gained more support and it is generally accepted that the quality of the embryo is not compromised via the freezing process.
“Using frozen embryos is potentially also better for the mother as we avoid the risk of ovarian hyperstimulation, which can make mothers extremely ill and can require hospital admission and, in some rare cases, even lead to death.
“This trial will help to gather robust data allowing us to compare the advantages and disadvantages of each method in a large number of couples.
“Another aspect that we will be considering is the cost of each method to the NHS and the long-term cost to society. There are financial implications for caring for a preterm baby, for example, so these are aspects that will be taken into account.
“We are all excited about getting this trial up and running. It has already received publicity at conferences and the fact that 12 centres across the UK will participate in this trial is testament to how interested the medical community is in evaluating the use of frozen embryos which in future could affect almost every aspect of IVF.”
Recruitment for the study got under way this week, with the trial set to conclude by the end of 2017.
* In the context of the trial, a healthy birth will be considered to be one baby delivered after 37 weeks, within normal weight parameters.