4 randomized controlled trials have recently shown that PGS for 23 chromosome pairs increases implantation rates at least by 1/3.
PGD for 23 chromosome pairs increases implantation rates at least by 1/3.
|Randomized controlled trials||Patient group||Fresh or freezing||Implantation rate after PGD for 23 chromosome pairs vs control|
|Yang et al. 2012||<35||day 5 biopsy, day 6 fresh transfer||40% increase|
|Schoolcraft et al. 2012||>35 (av 39)||day 5 biopsy, freezing, FET||32% increase|
|Forman et al. 2013||>35||day 5 biopsy, day 6 fresh transfer||32% increase|
|Scott et al. 2013||20-42 (av. 32)||day 5 biopsy, day 6 fresh transfer||28% increase|
For example :
Schoolcraft et al. 2012 have shown in women above 35 year old (mean age 39) implantation rates is 56,7% after PGS for 23 chromosome pairs and only 38% implantation rates in controls after frozen embryo transfer. Miscarriage rates in control group were 17% and 0% after PGS.
The same results were shown in 2013 by Forman et al in the same patient group (women in the age 35 or older: 58,3% implantation rates in PGS group and 39,8% implantation rates in control group.
In summary the benefit of PGS for 23 chromosome pairs is:
- Helps to choose the right embryo for transfer to the uterus not only on the basis of “good looks” but also with the knowledge of correct chromosome set
- Increases pregnancy and live birth rates per embryo transfer
- Reduces time to pregnancy via excluding chromosomally abnormal good looking embryos from usage
- Helps to avoid unnecessary embryo transfers
- Helps to avoid freezing of chromosomally abnormal embryos
- Reduces miscarriage rates
- Reduces the Down syndrome risk
- Explains multiple unsuccessful IVFs (RIF)
- Eliminates negative effect of maternal age on implantation