Jose G Franco Jr, Claudia Petersen, Laura D Vagnini, Fabiana C Massaro, Bruna Petersen, Andreia Nicoletti, Juliana Ricci, Camila Zamara, Isabela M Pasotti, Renata A Pouza, Bianca C Matuella, Elisangela V. Espirito-Santo, Joao B Meziara, Antonio H Oliani, Joao Batista Oliveira
JBRA Assist. Reprod. - Advanced View
Received June 01, 2026
Accepted June 02, 2026
Abstract
Objective: To determine whether studies evaluating preimplantation genetic testing for aneuploidy (PGT-A) reach different conclusions depending on the denominator used to calculate live birth rates.
Methods: A systematic review of studies published between 2017 and 2025 was conducted using PubMed, Scopus, and Google Scholar. Randomized and non-randomized studies comparing IVF/ICSI cycles with and without PGT-A were included. Outcomes were analyzed per initiated cycle, oocyte retrieval, or embryo transfer. Relative risks were calculated using a random-effects model.
Results: Eleven studies were included. No significant difference was observed when live birth rates were analyzed per initiated cycle or oocyte retrieval (RR 1.04, 95% CI 0.91–1.18). However, PGT-A significantly improved live birth rates when analyzed per embryo transfer (RR 1.21, 95% CI 1.05–1.40).
Conclusion: The apparent benefit of PGT-A depends on the denominator used. Reporting outcomes per embryo transfer introduces selection bias and overestimates treatment effectiveness. Clinically meaningful outcomes should be reported per initiated cycle or oocyte retrieval.
