Is embryo testing worth it?

If you’re going through IVF, you may be offered a test to assess your embryos called PGT-A. It stands for preimplantation genetic testing for aneuploidy.

PGT-A is an ‘add-on’ used to help choose embryos with the right number of chromosomes. It is often recommended for women over the age of 35 who have a higher rate of embryos with an abnormal number of chromosomes than younger women. It may also be recommended for women who have previously experienced miscarriages or a diagnosis of chromosomal abnormality during pregnancy.

The idea is to avoid the time and stress of transferring embryos with an abnormal number of chromosomes and to prioritise the ones that are most likely to work.

While this might sound helpful, there is debate among fertility specialists and scientists about how beneficial PGT-A is. Some experts say it may even reduce your chance of having a baby. So, here is our independent summary of what is currently known about the test.

Does PGT-A improve the chance of a having a baby?

While some studies have demonstrated a higher implantation rate for embryos that were selected after a PGT-A test there is no reliable evidence that it improves the chance of having a baby.

Some researchers have also questioned the design of research showing PGT-A improves outcomes, saying the studies were done in selective populations and that the results therefore cannot be trusted.

What are the potential downsides?

Some researchers say that PGT-A may reduce a woman’s chance of having a baby for the following reasons:

• The removal of cells from an embryo to do the test may affect the implantation potential of the embryo.
• PGT-A can lead to ‘false-positive’ results, meaning healthy embryos are discarded. This is based on the potential for PGT-A to classify ‘mosaic embryos’ (embryos with a mix of normal and abnormal cells) as abnormal. The problem with this is that mosaic embryos are surprisingly common and can grow into healthy babies. Healthy babies have been born to people who have chosen to have mosaic embryos transferred. In a study of 98 women who had mosaic embryos, 32 (33 per cent) elected to have at least one transferred. Of these, 11 (34 per cent) had a successful pregnancy.
• The cost of using the test is about $700 per embryo, so if you used it to test seven embryos from one cycle of IVF, the cost may be the equivalent of having another cycle that produces more embryos.

If you are considering PGT-A, VARTA recommends asking your doctor the following questions promoted by Choosing Wisely: ·

• Do I really need this test?
• What are the risks?
• What are the costs?
• Are there simpler, safer options?
• What happens if I don’t use it?