First use of DNA fingerprinting to identify viable embryos

• that up to 20 trophectoderm cells can be removed from a blastocyst without adversely affecting its viability and ability to implant;
  
  
• DNA fingerprinting is a very useful technique for discriminating between viable and non-viable blastocysts;
  
  
• trophectoderm cells from viable and non-viable blastocysts have different patterns of gene expression, which, when refined, could be used to select the single most viable embryo from a group for transfer.
  
  

Although more work needs to be undertaken before these findings become applicable in the clinic, the researchers say that their work will also be useful for testing different treatments of embryos without the need to recruit large numbers of women to clinical trials, and DNA fingerprinting could be used to refine existing criteria for selecting embryos for implantation.

Dr Jones said; “Major improvements in IVF practice in the last decade have seen the introduction of better laboratory techniques that allow complete pre-implantation development to the blastocyst stage in vitro. One of the major stumbling blocks to worldwide acceptance of a single embryo transfer policy is the lack of highly predictive criteria to select the single most viable embryo within a cohort. The ability to use objective, measurable criteria rather than subjective observations, such as morphology, should improve the predictive value and provide sufficient confidence for clinicians to shift towards single embryo transfers for all patients without a concomitant drop in pregnancy rates. This would effectively reduce multiple pregnancies, which is a priority in the field of assisted reproductive medicine at present.”

[1] Novel strategy with potential to identify developmentally competent IVF blastocysts. Human Reproduction. Published online under advance access. doi:10.1093/humrep/den123.

[2] The blastocyst is the stage at which the embryonic cells have started to differentiate into the different cell layers that will go on to form the foetus or the placenta.

[3] Messenger RNA (or mRNA) is a key intermediary in gene expression, translating the DNA’s genetic code into the amino acids that make up proteins.