Preimplantation Genetic Testing for Aneuploidy Versus Morphological Selection in Women Aged 35-42: Results of a Pilot Randomized Controlled Trial

Abstract

Background/Objectives: Embryo selection in IVF is traditionally based on morphology, yet many high-quality embryos fail to implant. Preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing (NGS) has been proposed to improve selection by identifying euploid embryos. However, its effectiveness in women of advanced maternal age remains unclear due to limited randomized data. This pilot trial assessed the feasibility of a full-scale RCT comparing PGT-A to morphology-based selection in women aged 35-42. Methods: This single-centre, two-arm parallel RCT (NCT05009745) enrolled women aged 35-42 undergoing IVF/ICSI with ≥3 good-quality day-3 embryos. Participants were randomized (1:1) to either embryo selection by morphology with fresh transfer or PGT-A with frozen transfer of a single euploid embryo. Allocation concealment was achieved via a secure web-based randomization platform; patients and clinicians were unblinded, but the biostatistician remained blinded. The primary outcome was feasibility of recruitment, randomization, and adherence. Results: Between June 2021 and January 2023, 138 women consented (recruitment rate: 55.8%, 95% CI: 49.7-62.0%) and 100 were randomized. Protocol adherence was 94%. Barriers to recruitment included preference for private PGT-A (19%) or fresh transfer (6%). Among biopsied embryos, 51.4% were euploid and 6.6% low-level mosaic. Intention-to-treat analysis showed no significant differences between PGT-A and control groups in clinical pregnancy rate (50% vs. 40%), live birth rate (50% vs. 38%), or miscarriage rate (12% vs. 8%). Cumulative live birth rate after up to three SETs was 72% vs. 52%, respectively (p > 0.05). No multiple pregnancies occurred. Conclusions: RCTs of PGT-A in older women are feasible. A multicentre design with broader inclusion criteria could improve recruitment and allow better assessment of clinical benefit.

Keywords: IVF; aneuploidy; embryo mosaicism; preimplantation genetic testing.

Figure 1

Patient flow diagram outlining recruitment, randomization, treatment allocation, and follow-up in the trial assessing the effectiveness of PGT-A on clinical outcomes.