IVF is a complex process that involves retrieving eggs from ovaries and manually combining them with sperm in a lab for fertilization. It is critical to consider all of the steps that you need personally to have the best IVF cycle with hopeful outcomes. Some IVF experiences span about 4-6 weeks, for those not doing the Preimplantation Genetic Testing or doing it with Aneuploidy (searching for chromosomal abnormalities). When it comes to Preimplantation Genetic Testing for Monogenic Disorders (For me, Huntington’s), this entire process can take 3-6 months, as the probe can take 4-12 weeks for creation, 2-4 weeks for the egg retrieval, and then 1-2 weeks for embryo biopsy, testing and results. I am already feeling the high stress and since I am in the waiting stage of this process, I feel like time is not moving. Waiting the month or more for the creation of the probe, has me feeling incredibly anxious and understand the intense anxiety and stress that other women have mentioned.

The first step is to be in contact with the genetic testing company that is connected with your fertility clinic. For me, it is Cooper Surgical. I collected all of the information I thought they’d need, from medical records (both mine and my fathers) that show our genetic mutations, and signed all the necessary consents. I provided Cooper with the information on my chosen sperm donor as well as plan to buy an extra vial of sperm in case they need it for probe development. I also had a genetic counseling appointment scheduled to go over the information for my specific case of genetic testing before they are able to start creating the probe. They have collected DNA from me, the sperm donor, and my mother in order to continue. My specific sperm bank was able to send a sample for a reduced price for the genetic aspect of my donor so I did not have to purchase another vial of sperm. Once all needed information and DNA has been collected, scientists can analyze the DNA to create a probe that detects the specific gene, in my case the HTT gene. Creating the probe and the full testing process can take about 4 weeks, but luckily, the IVF process can start before the probe is finished. I can move forward with the retrieval process, but the genetic testing does not start until the embryos are created and samples are sent to Cooper. The information above is regarding PGT M but if you were only doing PGT A, the biopsy and results take a significantly shorter timeframe due to not needing a specialized probe.

Once the embryos are created, they are grown to the blastocyst stage (5-7 days after fertilization that consists of the inner cell mass which’ll become the fetus and the trophectoderm which is the future placenta). This is a key stage as it signals high potential for development and implantation rates. At the blastocyst stage, there is a trophectoderm biopsy where they take a few cells from the embryos (5-10 cells), then freeze the embryos and finally test the embryos using the probe that was created. In my case, they would use the probe to test the embryos for the HTT gene. This has about a 95%-98% accuracy rating. The unaffected embryos are eligible to be transferred into my uterus and the affected embryos remain frozen or are donated to scientific research.

Once you receive the results of the embryo biopsy (7-14 days), and know which embryos are affected and which are not (if any), there is a difficult decision to be made. If there are embryos that are affected by the specific gene or have chromosomal abnormalities, the question becomes what will you do with the affected embryos? I believe I’ve spoken about this in another post but you have a couple of options to choose from. You can discard the embryos as medical waste, you can donate the embryos to research (what I have chosen to do to improve the understanding of the HTT gene and how it is transmitted), you can donate the embryos to another couple in need (usually reserved for extra healthy embryos rather than unhealthy ones), or they can be kept in long term storage. There is one other way for these affected embryos, which is less common, which is something called a compassionate transfer, where the embryo is implanted during a non-viable time of a woman’s cycle to allow for a natural end.

The accuracy of PGT is incredibly high at 95%-98%. It significantly improves implantation rates and reduces miscarriages; one potential downside is, it can create embryo mosaicism or other technical factors. Mosaicism is where the biopsied cells may not match the genetic makeup of the inner cell mass that becomes the fetus. There is a potential for misdiagnosis, while rare, which can result in false positives or false negatives potentially leading to the disposal of viable embryos or the transfer of abnormal ones. This does not guarantee a success pregnancy or a healthy baby as there is other factors that can cause miscarriages. An amniocentesis is a type of test that can confirm the PGT results during pregnancy. A limitation is that the test relies on biopsied cells, and if the sample is damaged or poorly representative of the whole embryo, the result may be inaccurate. The accuracy of PGT results depends on the quality of the laboratory techniques and while it is rare, human errors in handling or testing may occur. While PGT has high accuracy rates, it is important to prepare yourself for any outcome regarding your tested embryos.

There are some genetic diseases, such as Huntington’s Disease, that may not develop or show symptoms until adulthood, while still being genetically present. That can make it more difficult to see if the PGT worked the way it should’ve, so couples/mothers are encouraged to pursue additional prenatal testing. One important thing that people need to realize is that Preimplantation Genetic Testing is NOT used to create genetically “perfect” children. While it can choose gender if wanted for family balance, it cannot select physical characteristics such as height, hair or eye color. PGT testing is strictly for those more at risk for a specific disease or abnormal numbers of chromosomes.

The best case scenario is that after testing the embryos, there are a couple with unaffected status’ which are ready to implant. By the time the results are ready, you may have prepared your body for a Frozen Embryo Transfer. These blastocysts have been graded by expansion and given a 1-6 and an A-C for cell quality with 3AA, 4AA, and 5AA as possible top grades. The expansion indicates how much the blastocyst has grown, 1 is early, 4 is expanded, 5 is hatching, and 6 is hatched. When determining the inner cell mass, which turns into the fetus (first letter), ‘A’ is best (many, tightly packed cells), and ‘C’ is poor (few, sparse cells). The Trophectoderm (the outermost layer of the blastocyst), develops into the placenta (second letter), and the A grade is best with many cohesive cells and C is poor with few sparse cells. The excellent and top quality grades are 4AA, 5AA and 3AA, good and fair grades are 4AB, 4BA, 3AB, 3BB, 5BB, and poor are 3BC and 4CC. Good (A-grade) embryos show excellent morphology, while fair (B-grade) embryos are slightly less compact or symmetric but still yield high pregnancy rates.

Once a graded embryo is chosen for implantation, the embryo transfer can occur, which typically only takes around 2-5 minutes. The process is fast because it requires no anesthesia, relies on ultrasound guidance for speed and accuracy, and is performed after weeks of preparation have already taken place. The transfer is the final step after weeks of medication to prepare the body for implantation. There is then a 2 week wait before you go back in for a pregnancy test to see if the transfer took. I’ve heard this time is excruciating and women are told to not take a pregnancy test at home as those may not be as accurate. If you receive a positive pregnancy test, an amniocentesis procedure is recommended between weeks 10-15 of pregnancy to confirm the genetic test result from the embryo biopsy. Genetic testing is about 98% accurate, but it is recommended to double check in pregnancy to be sure.