A meta review of 11 studies comparing outcomes of some 37,000 pregnancies using IVF shows that cryopreservation seems to reduce the chances of premature birth, low birth weight and ante-partum haemorrhage. An associate risk with the use of cryopreservation seems to be an increase in caesarean section, although overall the difference in risks following fresh and cryopreserved embryo transfer was low.
Researchers from the University of Aberdeen and Aberdeen Maternity Hospital, lead by Dr Abha Maheshwari, undertook the study and published results in the journal Fertility and Sterility presenting it at the British Science Festival recently. http://www.fertstert.org/article/S0015-0282(12)00573-0/abstract
This follows another study undertaken by the British Fertility Society, who presented similar findings, reported by the BBC http://www.bbc.co.uk/news/health-16430139
Estimates say there have been perhaps half a million cryopreserved births since Zoe Leyland's in 1984. The Aberdeen research goes back many years in some cases - when nearly all embryos were cryopreserved using slow freezers. The new vitrification technique has been experimented with since the 1980s but has only been in mainstream use over the last four or five years, so much of the data being used may relate to controlled rate freezers.
Dr Abha Maheshwari is interested in expanding the study and if researchers have data to share she is happy for them to contact her at This email address is being protected from spambots. You need JavaScript enabled to view it.
For more information on our range of freezers, please visit to the Planer Cryo Freezer page. http://planer.com/products/cryo-freezers/small-crf/kryo-360.html