Embryo Genetic Screening

One of the greatest advances in the field of IVF is the opportunity to incorporate some incredible technologies developed in the diagnostic and genetic screening spaces.

With my background in genetics, I generally see quite a number of patients who come to see me with either a known family history of a genetic condition or who themselves are carrying a known genetic condition. In some circumstances, people may choose embryos screened before implantation to preferentially select those that don’t carry specific genetic issues.

This process usually involves generating embryos by IVF and growing these in the incubator to the blastocyst stage. At that point, a few cells are removed from a specific part of the developing embryo, and those cells are used for the genetic test. The embryo is then frozen until the test results are available. Various testing strategies can be adopted.

PGT-A - Preimplantation Genetic Testing for Aneuploidy

We have 46 chromosomes. When an embryo is generated, 23 chromosomes come from an egg, and the other 23 chromosomes come from the sperm. The most common cause of miscarriages occurs when an embryo has either too many or too few chromosomes. Screening for these chromosomal changes can potentially reduce the time taken to achieve a live birth.

Alternatively, some people may choose to strategically bank screened embryos so they can have some element of confidence if they are planning for several children and are aware that ovarian reserve decreases with age and risks of chromosomal issues increase with increasing age.

PGT-M - Preimplantation Genetic Testing for Monogenic (single gene) conditions

I will offer a wide variety of genetic screening tools to you to consider as part of your initial fertility workup. Whilst you obviously don’t have to screen for any condition, you may decide to screen for just a few genes, or conduct an extensive screen of over 1000 genes.

Occasionally, both you and your partner/donor are carriers of a specific autosomal recessive condition. In these cases, we have an extensive chat with our genetics team and consider the option of screening embryos that are unaffected by the condition.

We can also screen for X-linked and autosomal dominant conditions. On occasion, you may have a family history of certain conditions that can be inherited dominantly, but you may have made the decision that you do not wish to know your individual status. We do have the opportunity to screen embryos for such conditions without you finding out your status. In these circumstances, we can combine PGT-A and PGT-M screening techniques, and the only information we have is whether embryos are suitable or not for transfer.