Preimplantation genetic testing for aneuploidy (PGT-A) in the USA avoided nearly 15 000 miscarriages and over 6500 preterm births in 2023: an opinion

Recently, through analysis of Society for Assisted Reproductive Technology (SART) data, we provided evidence that preimplantation genetic testing for aneuploidy (PGT-A) improves implantation, miscarriage and pregnancy rates per egg retrieval. In this review (using 2023 SART data), we concentrate more closely on pregnancy loss, preterm birth and elective single embryo transfer (eSET). Aneuploidy causes ~65% of pregnancy losses and we ask: (1) what is the association between pregnancy loss and PGT-A (with/without eSET)?; (2) is there an association between (very) preterm birth and PGT-A?; (3) how many pregnancy losses or (very) preterm births were avoided using PGT-A?; and (4) how many could have been avoided using PGT-A? Significant associations were observed between miscarriage rate and PGT-A: a greater rise associated with maternal age in the PGT group. The youngest age group showed a significant effect of PGT, the oldest PGT patients having a similar miscarriage rate to the youngest not using it. Effects were greater in the eSET group, and there was a significant difference in favour of PGT when considering the rate of (very) preterm birth. We calculate that ~14 983 miscarriages were avoided by using PGT, and that ~11 419 could have been avoided if PGT had been used; ~6619 (very) preterm births were avoided by using PGT and ~3636 could have been avoided. These analyses complement clinical trial studies with profound implications for the use of PGT-A; moreover, although groups are not randomised nor matched as in trial studies, sheer force of numbers suggests that we are observing genuine biological phenomena.