Giving Families a Chance: Non-Invasive Genetic Testing

What Is Genetic Testing?

Pre-Implantation Genetic Screen (PGS or PGT-A) is a preventative measure used to screen embryos for chromosomal abnormalities. Chromosomes determine everything from hair color to what diseases a person may be susceptible to. An average fertilized egg has twenty-three pairs of chromosomes—forty-six in total—received from the sperm and ovum that form the embryo. These include two sex chromosomes (XY for males and XX for females). These healthy embryos are called euploid. PGS aims to search for aneuploidy or the presence of an abnormal number of chromosomes in a cell or structural abnormalities with those chromosomes.

Chromosomal abnormalities are common causes of birth defects that can affect the brain and other parts of the body. An example of aneuploidy includes Trisomy-21, also known as Down Syndrome, where there are three copies of chromosome 21 rather than the typical pair. A chromosome may have a structural abnormality, including a missing portion of a chromosome, a duplication, or a transfer to another chromosome. These genetically abnormal embryos are unlikely to survive. An aneuploid embryo most likely will not implant and thus will not result in pregnancy, but it can also cause a miscarriage later on in the pregnancy, and in rare cases, it can lead to a genetic disorder in the child. PGS increases the chance of pregnancy and lowers the rate of miscarriage by ensuring that only genetically healthy embryos are transferred into the surrogate.

A Non-Invasive Approach

When intended parents previously considered PGS, the only option was an invasive approach that created a risk of damaging the embryo. Under that method, the eggs and sperm were combined in a lab, and the embryo developed for five to seven days. At that point, the embryo had about 100 to 150 cells. Invasive PGS requires placing a needle into the embryo’s outer layer and removing a few cells. These cells in the outer layer develop into the placenta that surrounds a developing fetus.

A new technique has been proven to be a safer alternative to invasive PGS. Non-invasive Preimplantation Genetic testing (Ni-PGTA) is a method based on sampling DNA from the culture media surrounding the embryo. Cultural media is designed to mimic the composition of fluids in an embryo’s natural environment that allows it to develop. As those embryos develop, they release DNA into the media. Ni-PGTA is a cell-free technique that takes the DNA shed by embryos rather than removing cells from the embryo itself. The Ni-PGTA report from the genetics lab will indicate which embryos have the usual number of chromosomes. Additionally, intended parents can know the sex of the embryos if they wish.

The Cost of Ni-PGTA

Not only is Ni-PGTA safer for the embryo, but it is also less expensive. PGS is an invasive procedure that carries high costs attributable to staffing embryologists, purchasing special equipment, and conducting embryo biopsies. Intended parents can expect to pay between $2,000 to $10,000 depending on insurance coverage. Non-invasive PGTA is less labor-intensive and a more cost-effective method that is covered under some insurance.

Ni-PGTA can also save intended parents time and money in the long run. While the pregnancy itself can sometimes alter an embryo’s health, the chromosomes themselves will usually determine how well the baby develops. By using genetic testing, intended parents can catch abnormalities early and assess the viability of the embryo. For example, imagine that intended parents decided not to do the test and went on with the pregnancy. In this case, the surrogate may experience a difficult pregnancy, or even a miscarriage, because of an abnormality within the embryo. This takes the family back to square one of fertility treatments. By using Ni-PGTA, intended parents can assess from the beginning whether an embryo has a chance of surviving. When the test comes back that the embryos are healthy, they can be transferred to the surrogate and assure all the parties that there is a greater likelihood of a successful transfer.

Is It Right for Me?

Ni-PGTA testing can be beneficial for intended parents that are:

• Over the age of 34;
• Have experienced repeated IVF failure;
• Have a history of miscarriage;
• Wish to reduce the risk of miscarriage and genetic abnormalities;
• Are interested in sex selection; and
• Don’t want to incur cryo-storage fees for chromosomally abnormal embryos.

For families forming embryos specifically for the purposes of conceiving with the assistance of a gestational surrogate, there is an added set of considerations. The first is financial: Intended parents incur fees associated with the transfer, often travel expenses, and compensation for the surrogate beginning with the confirmation of fetal heartbeat. If the embryo is chromosomally abnormal, they can avoid these costs. The second is emotional: Each embryo step of the process is an emotional roller coaster. Will the embryo transfer be successful? Will the fetus grow and develop? Will the baby be healthy? Will there be an issue with the fetus that will cause the intended parents to ask the surrogate to make the difficult decision to terminate the pregnancy? While there are no guarantees in surrogacy, intended parents can help control this variable and minimize some of the emotional toll on themselves and the surrogate.

The decision to use assisted reproductive technology (ART) is often a long and winding journey filled with tearful moments and heartache. ART and genetic testing can give back power to those couples to help finally achieve their dream of building a family.