Research looking at difference in pregnancy and live birth rates in good quality embryo’s vs. low quality ones.
Egg being fertilized in IVF treatment
In this research they compared good quality embryos to poor quality embryos. They had 3 different age categories under 35, 35 - 39 and 40 and older. They also compared genetically tested (PGT) embryos to ones that were not PGT tested. They found that for < 35 and the 35 - 39 age group embryo quality made a difference for pregnancy and live birth rates. For the over 40 the difference was less. For the poor quality embryos they found that genetic testing also led to higher pregnancy and birth rates (40% for both), but still a pregnancy rate of 29 % and a live birth rate of 22% for non-tested poor quality embryos.
Link to research