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Frozen embryos are more likely to produce successful, complication-free IVF pregnancies than those that are fresh, research suggests.Read the full story ›
Daybreak's Health Editor Dr Hilary Jones has said that more research is needed before scientists can say for certain that frozen embryos are more likely to better IVF pregnancies.
The results of this analysis are counter-intuitive since 'second best' embryos are generally selected for storage, and are then subjected to freezing and thawing procedures each of which carries risk.
Albeit that the findings are difficult to explain, they are important in that they provide reassurance for cryopreservation programmes about short-term outcome.
This is an encouraging study that provides some evidence that the pregnancy and early outcome for babies may be better after embryos have been frozen.
It is of some concern that conclusions have been drawn, incorrectly... that we should routinely freeze all embryos and transfer them in a future menstrual cycle.
There is ample evidence to show that this would result in fewer pregnancies even if the outcome for those pregnancies were better.
I'd have to sound a cautious note about suggesting that all IVF embryos should be frozen, because the study doesn't support that.
It only looked at successful frozen cycles. What it does do is give support to the idea that transferring one fresh embryo and freezing the others is okay.
Freezing all embryos would have a catastrophic effect on pregnancy rates.
The existing data do have a number of limitations which need to be addressed in the context of further research before this strategy should be rolled out into routine clinical practice.
The initial step must be to provide robust evidence to demonstrate that elective freezing of embryos can increase the chances of having a healthy baby, which would be best performed in the context of a large randomised controlled trial.
In the meantime my advice to women undergoing IVF is that there is no reason, yet, to change the way they approach IVF.
- Frozen embryos are more likely to produce successful, complication-free IVF pregnancies than those that are fresh, new research suggests.
- Scientists made the discovery after analysing data from 11 international studies involving more than 37,000 IVF pregnancies.
- In some cases, newly conceived fresh embryos were used. In others, embryos that had been frozen and stored for two to three months were implanted.
- Standard practice is to choose the best embryos for fresh transfer, and only freeze those of good enough quality that are spare.
- But the new results suggest it might be wise to freeze all embryos.
During in vitro fertilisation (IVF) or intra-cytoplasmic sperm injection (ICSI) treatment, fertility drugs are used to stimulate the ovaries to produce more eggs than usual.
These are then fertilised with your partner’s, or a donor’s sperm to create embryos.
Because there is normally a number of unused embryos, some people choose to freeze the good quality unused embryos for use in later treatment cycles or for donation.