Subscribe to the BioNews newsletter for free

Advanced Search

Search for

Print Page Follow BioNews on Twitter BioNews RSS feed

Like the Progress Educational Trust on Facebook

King's College London - Health: More than a medical matter

Correction: Slow-frozen embryos seem to produce healthier babies in IVF

24 November 2008

By BioNews

Appeared in BioNews 485

In BioNews 484, we published a story reporting on new evidence to suggest that in IVF 'vitrified' embryos may be better than 'fresh' embryos. It has been brought to our attention that the technique used to store embryos in these studies was in fact 'slow-freezing', or 'controlled-rate freezing', and not vitrification as reported.

Controlled-rate freezing avoids the formation of potentially damaging ice crystals by allowing time for the concentration of solutes in the embryo to reach equilibrium in a cryoprotectant (a form of anti-freeze), before cooling in a predetermined, controlled way. Vitrification also aims to avoid the formation of ice crystals in the embryo, but does so by boosting the levels of cryoprotectant in order to avoid freezing and produce a glassy or 'vitreous' state at very low temperature.

While controlled rate freezing has been used in embryo storage since the 1980's, resulting in hundreds of thousands of healthy births, vitrification is, by comparison, a relatively new technology, which has so far only been attempted in a relatively small number of births. It would therefore have been impossible to achieve the large sample sizes recorded in these studies if not using the significantly more established slow-freezing technique.




17 November 2008 - by Alison Cranage 
Three new independent studies have provided further evidence that embryos stored using slow-freezing techniques may be better than fresh for IVF. The studies were presented at the American Society for Reproductive Medicine conference in San Francisco, US, last week. The studies indicate that using frozen embryos rather... [Read More]

Be the first to have your say.

You need to Login or Register to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions



- click here to enquire about using this story.

Printer Friendly Page

Published by the Progress Educational Trust
FREE public event in central London, 6.30pm on Thursday 8 May 2014 - find out more HERE

Please donate HERE, so that the Progress Educational Trust can continue throughout 2014 (and beyond) while keeping BioNews FREE for you to read

The Progress Educational Trust was shortlisted for the Charity Times Awards 2011

Advertise your products and services HERE - click for further details

Good Fundraising Code

Become a Friend of PET HERE, and give the Progress Educational Trust a regular donation