Frequently patients ask me if I can screen their embryos to ensure they are free of genetic disease. Genetic disease is either expressed though a specific genetic problem such as Cystic Fibrosis or through a mathematical error in chromosomal division and multiplication that improperly renders the genetic blueprint.
While the human body is very good at “screening” embryos – abnormal embryos will most often fail to implant and grow – new technology provides reproductive specialists further insight as to why an embryo doesn’t result in a healthy baby.
If, after consultation with a doctor, it is determined that a patient is a good candidate for embryo screening, they will undergo an IVF cycle with pre-implantation genetic screening (PGS).
After egg retrieval and fertilization, in most cases RSC will biopsy the embryos at the blastocyst stage. The embryos will then be safely stored at our clinic, while a sample of cells from each embryo will be analyzed at a laboratory that specializes in PGS. Once the results are received, patients undergo a frozen embryo cycle and transfer back one or two healthy embryos.
As new technology emerges, scientists continually debate over which technique will produce the best results. Currently, a hot topic among reproductive specialists is the choice between CGH and SNP microarray. At RSC we have the ability to choose a local laboratory for the best test, based on the clinical scenario specific to each patient.
RSC utilizes the SNP microarray at Natera for the following reasons:
- “Natera can detect haploidy, triploidy and UPD across all chromosomes and determine the parental source of the aneuploidy.”
- A three-step process ensures the greatest chance for detecting chromosomal deficiency.
- “Natera collects a sample from each of the gamete contributors (parental blood, cheek cells or sperm) and receives biopsy samples from each embryo created in the IVF laboratory.”
- “Whole Genome Amplification (WGA) + Single Nucleotide Polymorphism (300,000 SNPs) microarrays are performed.”
- “The parent blueprints and each embryo measurement are analyzed together using a combination of five different proprietary algorithms allowing Natera to provide an individual confidence for each chromosome pair with typically ≥99 percent accuracy.”
A higher confidence of a true result, the ability to know “who caused the error” and why, and the ability to detect UPD – which can be missed with CGH – are all reasons why we use SNP most often.
Combining our excellent blastocyst culture conditions, delicate biopsy of the embryo and outstanding frozen embryo transfer results, we are able to provide patients with knowledge of the best chance for success, providing them the confidence they need to move forward as parents.