Evolution of Assisted Reproductive Technology in Thailand: A National Registry Analysis of the Freeze-All Era (2017-2023) in a Global Context

Introduction: Thailand’s assisted reproductive technology (ART) practice has shifted towards a “freeze-all” embryo transfer strategy following regulatory reforms in 2015, but national outcomes in this post-regulation era have not yet been analysed. Aims: To analyse ART treatment trends, efficacy and safety in Thailand from 2017 to 2023 and compare these outcomes with prior Thai registry data and international benchmarks. Methods: We performed a retrospective analysis of 105,354 ART cycles reported in the Thai national ART registry from 2017 to 2023. Cycle volume, the utilisation of fresh versus frozen embryo transfer (FET), clinical pregnancy rate (CPR) per transfer, live birth rate (LBR) per transfer and complications (e.g. ovarian hyperstimulation syndrome, OHSS) were assessed over time. Outcomes were compared with earlier Thai registry phases (2001–2007, 2008–2014) and with the International Committee for Monitoring ART (ICMART) global most recent reports (2017–2021). Results: The number of initiated ART cycles grew from 11,924 in 2017 to 18,189 in 2023. By 2023, 94.7% of embryo transfers were performed as FET. This shift was accompanied by higher efficacy, with a CPR per transfer of 52.0% for FET versus 33.7% for fresh transfers. Thai FET outcomes surpassed international averages (2021 LBR: 36.3% vs. 29.5% globally). The safety profile also improved, as the mean number of embryos transferred declined to 1.34 and the incidence of severe OHSS was 0.4%. Conclusions: From 2017 to 2023, Thailand achieved marked improvements in ART success rates and safety by embracing a freeze-all strategy. These national results surpassed previous domestic benchmarks and compare favourably with global standards, underscoring the maturity of Thailand’s ART practice.