PGT-A did not improve live birth rate in clinic trial

A recent study found that preimplantation genetic testing for aneuploidy (PGT-A) may not improve live birth rate.

PGT-A is an add-on that many fertility clinics offer, due to the belief that not transferring aneuploid embryos will help to reduce miscarriage rate and improve live birth rate. Previous research had suggested that it could help improve live birth rate for older women but there was little research into how it impacted outcomes for young, healthy women. PGT-A is also potentially undesirable as it involves discarding aneuploid embryos, which can leave intended parents with fewer to have transferred than conventional IVF treatment.

Professor Richard Paulson director of USC Fertility in Los Angeles, California who was not involved in the research said: 'If you are someone who is in a good prognosis group ... and you have three blastocysts, it is in your best interest to not do the genetic testing.'

The research, detailed in the journal New England Journal of Medicine, was carried out across 14 fertility centres in China. The randomised, controlled trial involved 1212 subfertile women, ages 20-37, who had a good likelihood of having a live birth due to no history of recurring miscarriages or IVF cycles where the embryo had not implanted.

Split equally into two groups the trial looked at the live birth rate within a year and with up to three embryo transfers for women who had IVF with ICSI with PGT-A, and without PGT-A. They found similar rates between the two groups with a live birth rate of 85.3 percent for women whose embryos received PGT-A screening and 82.5 percent for women whose embryos did not.

A lower rate of miscarriage was found in the group who received PGT-A (8.7 percent compared to 12.6 percent), but more women in the conventional IVF group had second or third transfers of their embryos within a year, suggesting there were more embryos available for this group.

The authors of the study conclude that while PGT-A is not supported for women with a good prognosis, their results are not necessarily applicable to older women or women who have experienced multiple pregnancy loss or implantation failure. They also note they used ICSI for all women in the study which is not used for all IVF patients and that the results could be affected by their decision to not transfer mosaic embryos in the PGT-A group.

In a commentary that accompanied the piece Dr Sebastiaan Mastenbroek an embryologist from University Medical Centres in Amsterdam, the Netherlands and others who were not involved in the research noted: 'According to the 2018 Fertility Clinic Success Rates Report of the Centres for Disease Control and Prevention, PGT was used in 37.7 percent of all IVF cycles that resulted in an embryo transfer,' in the USA. He went on to point out that although the FDA does not regulate some fertility clinic 'add-ons' in the USA now, the public is calling for increased regulation. He warned the sector must be careful to innovate 'responsibility 'to avoid potential class-action lawsuits in future.