Texas Fertility Center (TFC) physicians provide explanations about the embryo biopsy process
When patients need the help of assisted reproductive technology to create or expand their families, our TFC physicians often employ in-vitro fertilization (IVF) techniques. With IVF, the eggs and sperm are combined in a laboratory setting and then develop into embryos that are eventually transferred back into the uterus, hopefully resulting in a healthy pregnancy.
As part of the IVF process, our embryologists may perform embryo biopsies to assess the viability of the embryos before they are transferred into the woman’s uterus.
Understanding Day 3 (blastomere) embryo biopsy
Although originally embyo biopsies were performed on Day 3 (at the multi-cell stage), we now perform embryo biopsy on Days 5, 6, or 7 of embryonic development, at the blastocyst stage. Blastocysts have at least 128 cells, and during the biopsy process, 6-8 cells are removed. In contrast, Day 3 embryos typically have 6-10 cells and during biopsy, only a single cell (blastomere) is removed and then sent to the genetics lab for evaluation.
After the genetics lab performs the testing, they will send us a report for each embryo so that we will know which embryos are normal (have a normal number of chromosomes and/or are unaffected by genetic mutations), and which are abnormal. We then can transfer a single “normal” embryo and offer patients a much higher chance for pregnancy and delivery of a healthy baby. With a Day 3 biopsy, the evaluation occurs quickly enough that a normal embryo can be transferred during the same cycle as the egg retrieval. Because only one cell is removed, results from Day 3 biopsies are not as accurate as those obtained from Day 5-7 embryo biopsies. In addition, removing one cell from an embryo with only 6 to 10 cells can create more trauma to the embryo than removing 6 to 8 cells from a blastocyst that has developed to the point that it contains at least 128 cells.
Explaining the advantages of Day 5 (trophectoderm) embryo biopsy
Embryo biopsy performed on Day 5, 6 or 7 following the egg retrieval is called a trophectoderm biopsy. Although the actual procedure is similar to biopsies performed on Day 3, the embryo is much more developed with a trophectoderm biopsy, which allows the embryologist to removes several cells, rather than just one cell. Consequently, we see better accuracy of the testing as well as a reduced risk to the embryo. In addition, with trophectoderm biopsy, the embryo has developed to the point where only cells that will eventually form the placenta are removed instead of cells that will eventually form the baby.
During the biopsy procedure, our Austin embryologists use a laser to make a very small hole in the outer membrane that surrounds the embryo. They then very carefully remove the cells and send them to one of the country’s leading genetics labs for testing. Results typically return within seven-ten days. Although this is very fast, the primary disadvantage of trophectoderm biopsy is that we cannot get biopsy results back quickly enough to perform a fresh transfer. Therefore, all healthy appearing embryos are frozen after the biopsy is performed, and the transfer is performed in the following cycle.
At TFC, we have transitioned almost all of our patients to frozen embryo transfer, not only so that we can get the results of the biopsy, but also because recent data suggest that babies born following frozen embryo transfer may be even healthier than babies born after a fresh transfer.
Our team at Texas Fertility Center understands that the infertility treatment process is very involved. Our physicians and staff will answer questions and provide details about IVF, including embryo biopsy every step of the way.
Contact us for more information or to schedule an appointment with one of our fertility specialists.