Talk:Embryo cryopreservation

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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 20:39, 17 January 2022 (UTC)

Unreferenced text on safety

The following piece of text was found in IVF. However, since equivalent reports are already given in this article, I think this text needs a more specific link to the original study to justify insertion. Mikael Häggström (talk) 07:54, 8 June 2011 (UTC)

On the safety of embryo cryopreservation, a 2008 study reported at the European Society of Human Reproduction and Embryology discovered that children born from frozen embryos “did better and had a higher birth weight” than children born from a fresh transfer. The study was conducted out of Copenhagen and evaluated babies born during the years 1995–2006. 1267 children born after Frozen Embryo Replacement (FER), via controlled-rate freezers and storage in liquid nitrogen, were studied and categorised into three groups. 878 of them were born using frozen embryos that were created using standard in vitro fertilisation in which the sperm were placed into a dish close to the egg but had to penetrate the egg on their own. 310 children were born with frozen embryos created using ICSI in which a single sperm was injected into a single egg, and 79 were born where the method of creation of the embryos was not known. 17,857 babies born after a normal IVF/ICSI with fresh embryos were also studied and used as a control group or reference group. Data on all of the children’s outcomes were taken regarding birth defects, birth weights, and length of pregnancy. The results of the study showed that the children who came from frozen embryos had higher birth weights, gave longer pregnancies and produced fewer “pre-term” births. There was no difference in the rate of birth defects whether the children came from frozen embryos or fresh embryos. In the FER group, the birth defect rate was 7.7% compared to the fresh transfer group which was slightly higher at 8.8%. The scientists also found that the risk for multiple pregnancies was increased in the fresh embryo transfers. Around 11.7% of the ICSI and 14.2% of the IVF frozen cases were multiple pregnancies. In the case of fresh embryos, 24.8% of the ICSI and 27.3% of the IVF were multiple pregnancies. It should also be noted that maternal age was significantly higher in the FER group. This is significant since based on age one would have expected a higher rate of problems and birth defects. The study adds to the body of knowledge suggesting that traditional embryo freezing is a safe procedure. It was unclear however why the frozen embryo children did better than their fresh embryo counterparts.

It seems the text refers to this study:

• Wennerholm, U. -B.; Soderstrom-Anttila, V.; Bergh, C.; Aittomaki, K.; Hazekamp, J.; Nygren, K. -G.; Selbing, A.; Loft, A. (2009). "Children born after cryopreservation of embryos or oocytes: A systematic review of outcome data". Human Reproduction. 24 (9): 2158–2172. doi:10.1093/humrep/dep125. PMID 19458318.

I added some results of it. Still, feel free to complement if you find anything important missing from it. Still, let's try to keep it short and simple. Mikael Häggström (talk) 08:22, 8 June 2011 (UTC)

Alternative to abortion?

Is it possible to use this as an alternative to aborting an unwanted embryo or are the timescales incompatible. i.e you don;t find out your pregnant until after the timepoint where you would need to remove the embryo for preservation.131.251.252.33 (talk) 19:41, 15 October 2013 (UTC)

the history section is confusing. Did Trounson & Mohr discover embryo cryopreservation, or was it Subash Mukhopadyay?

History The first ever pregnancy derived from a frozen human embryo was reported by Alan Trounson & Linda Mohr in 1983 (although the fetus aborted spontaneously at ten weeks of gestation); the first term pregnancy derived from a frozen embryo was born in 1984.[15] Since then and up to 2008 it is estimated that between 350,000 and half a million IVF babies have been born from embryos frozen at a controlled rate and then stored in liquid nitrogen; additionally a few hundred births have been born from vitrified oocytes but firm figures are hard to come by. It may be noted that Subash Mukhopadyay, from Kolkata, India reported the successful cryopreservation of an eight cell embryo, storing it for 53 days, thawing and replacing it into the mother’s womb, resulting in a successful and live birth as early as 1978- a full five years before Trounson and Mohr had done so. A small publication of Mukherjee in 1978 clearly shows that Mukherjee was on the right line of thinking much before anyone else had demonstrated the successful outcome of a pregnancy following the transfer of a 8-cell frozen-thawed embryo into human subjects transferring 8-cell cryopreserved embryos." (Current Science, Vol .72. No. 7, 10 April 1997)

Perhaps the section should be rewritten along the lines. Credit for the first ever pregnancy is usually given to Alan Trounson & Linda Mohr in 1983...but some historians believe the first case was carried out by Subash Mukhopadyay, from India....