Genetic testing for embryos is a controversial issue but one thing is for certain, when women use this screening process – especially older women and those who have had repeat miscarriages – are less apt to miscarry implanted embryos and data from recent studies show that certain methods for genetic screening show significantly higher IVF success rates.
Deciding if Genetic Testing is Right For You? Here Are 7 Things to Consider
It’s widely known that genetic abnormalities are a leading cause of failed implantations and miscarriages. The process of screening the embryos beforehand allows doctors to select the most genetically viable options for an assisted reproductive technology that is never a guarantee.
Here are 7 things you will want to consider before you proceed with genetic testing before your IVF procedure.
- Understanding the difference between PGS and PGD. Not all genetic testing on embryos is considered equal. Currently, there are two different types: Preimplantation Genetic Screening (PGS) and Preimplantation Genetic Diagnosis (PGD).
–PGS. This type is the most commonly used and it solely screens for chromosomal abnormalities – i.e. how many chromosomes are there? Normally, a baby has 23 pairs of chromosomes. If this number is different, the embryo is chromosomally abnormal and would not be selected for implantation. This process does not identify specific indicators for diseases.
–PGD. This type of genetic screening looks for specific genetic conditions, such as cystic fibrosis, some types of cancer, or other hereditary medical conditions. These are rarely a guarantee that the baby will develop the disease but can simply indicate that the gene is present.
- Its history. PGS and PGD have existed since the 1990s but the processes and techniques have evolved considerably since then. They are still relatively new procedures but the success rates continue to improve the more we learn. In most cases, the genetic screening will be done using a single cell (or cells) from 3- to 5-day old embryos, depending on the procedure being used. Your doctor can discuss the various procedures and how timing can affect testing results and implantation with you further.
- Odds are, your embryo is chromosomally abnormal. Thus far, the tests done on embryos used for IVF purposes are considered chromosomally abnormal 50% to 70% of the time. This is worth noting. If you aren’t interested in a multiple birth, you will want a single embryo implanted. However, if it isn’t tested for chromosomal abnormalities first, you are definitely playing against the odds.
- Genetic testing doesn’t harm the embryo. If you are working with a reputable IVF clinic, the processes used for PGD and PGS tests will not harm the embryo. To date, there have not been any increased rates of pregnancy complications or genetic abnormalities in embryos that have been tested prior to implantation.
- 5. Who should consider genetic testing for embryos? The guidelines for who these genetic tests should be offered to are still under consideration. Typically, the most interested parties include:
–Women 38 years or older who are using IVF to get pregnant.
–Any women who have experienced repeat IVF failures to help determine why the embryos aren’t implanting and/or why the women are miscarrying.
–Women who have experienced recurrent miscarriages, typically three or more in a row.
–Couples who suspect or know they carry genes for serious medical conditions and would like to screen for healthy embryos ahead of time.
- 6. Electing to have your embryos screened does not make you a eugenicist. As we mentioned in the intro, eugenics is a hot topic of debate. If you share your decision to screen your embryos with others, be prepared for potential backlash. That being said, electing to have your embryos screened to improve your chances of IVF success does not make you a eugenicist; it makes you a concerned parent who is trying to do everything she/he can to have a healthy pregnancy and baby.
- 7. Preimplantation genetic diagnosis (PGD) does not replace traditional prenatal testing. The results you receive from preimplantation diagnosis (PGD) are only diagnostic indicators. Your pregnancy will still be monitored according to your doctor’s current standard of care. Routine prenatal genetic screening such as an amniocentesis or chorionic villus sampling will still be offered and/or recommended depending on your history.
Have you elected to have embryonic genetic screening prior to your IVF cycles? Please share your story in the RRC comment box below for others to learn from.
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