Embryo Testing Before Transfer
Couples pursuing in vitro fertilization (IVF) may want to consider preimplantation genetic testing (PGT) to learn more about the health of the embryos. PGT is performed on embryos before the specimen is transferred to the uterus to look for genetic problems. Although there are many benefits to the procedure, some patients may wonder if the embryo biopsy causes damage.
The IVF approach
With traditional in vitro fertilization, the woman is given medication to stimulate the growth of eggs in the ovaries. Next, the eggs are retrieved and combined with a sperm sample to create embryos. Once the embryos have grown for a few days in the lab, the specimen is transferred into the uterus in hopes of implantation. Although IVF is very successful, not every transferred embryo will result in a healthy baby. In some cases, the baby will be affected by a genetic condition like cystic fibrosis (CF) or a chromosomal abnormality, such as Down syndrome.
The power of PGT
With preimplantation genetic testing, a small number of cells are biopsied or removed from the trophectoderm of the early embryo. The cells are tested in a lab, and the patient receives the results shortly thereafter. Different types of genetic tests are available, with PGT-A screening for chromosomal abnormalities, PGT-M looking for specific genetic conditions, and PGT-SR used to find structural rearrangements. Depending on health history and carrier screening results, the fertility doctor will recommend the best test. Being able to identify the healthiest embryos for transfer can reduce the risk of miscarriage and increase the chance of a successful pregnancy. Here are 3 essential facts about preimplantation genetic testing.
1. No risks for the patient
Since the PGT procedure is performed in the lab, there are no additional risks to the patient from having this test done. However, in some cases, especially if the woman is older, a cycle may result in no genetically normal embryos. This means that an additional IVF retrieval and subsequent genetic testing will need to take place before a healthy embryo can be located.
2. Small chance of damage
In about 5% of cases, damage to the embryo can occur during the handling, biopsy, freezing, and thawing process. If this were to occur, the embryo would be discarded. In 95% of cases, the test is performed flawlessly, and a genetically normal embryo is transferred into the uterus, resulting in no additional risks for the pregnancy or the future child.
3. Not 100% accurate
Although preimplantation genetic testing is generally a safe procedure that increases a patient’s knowledge about the future child’s health, the woman or couple should understand that PGT is a screening test, not a diagnostic test. Although most individuals will garner helpful information from the test, the results are not 100% accurate.
Empowered with information
Preimplantation genetic testing is a game changer for future parents who want to learn more about the health of the embryo before transfer. Able to identify chromosomal problems and inheritable genetic issues, PGT can increase the chances of a healthy pregnancy. Risks to the embryo are small, and in most cases, the procedure is performed seamlessly.
