Preimplantation genetic testing for aneuploidies does not improve live birth rates for couples undergoing intracytoplasmic sperm injection because of severe male infertility, according to a large, randomised trial conducted in China. The intervention did, however, significantly reduce pregnancy loss.
Trial Design and Participants
The multicentre, open label randomised controlled trial was carried out across four reproductive medicine centres in China. Researchers enrolled couples with severe male factor infertility who were scheduled to undergo intracytoplasmic sperm injection, a commonly used assisted reproductive technique in this group.
Between July 2018 and January 2023, 1,347 couples were screened, of whom 450 provided informed consent and were randomly assigned in a 1:1 ratio to intracytoplasmic sperm injection with or without preimplantation genetic testing for aneuploidies. Each group included 225 couples. In the intervention arm, embryos were cultured to the blastocyst stage and genetically tested for chromosomal aneuploidies before transfer. In the control arm, embryos were transferred without genetic testing.
The primary outcomes were live birth after the first embryo transfer and cumulative live birth within 12 months of randomisation, allowing up to three embryo transfer cycles. Analyses were conducted according to the intention-to-treat principle.
No Improvement in Live Birth Rates
The study found no significant difference in live birth rates between the two groups. After the first embryo transfer, 48.4% of couples in the preimplantation genetic testing group and 46.2% in the no testing group achieved a live birth, a difference that was not statistically significant.
Cumulative live birth rates within 12 months were also almost identical. A total of 60.4% of women in the genetic testing group and 60.9% in the control group had a live birth, indicating that embryo aneuploidy testing did not increase the overall likelihood of having a baby for couples with severe male infertility undergoing intracytoplasmic sperm injection.
Reduced Pregnancy Loss with Genetic Testing
Despite the lack of benefit for live birth, preimplantation genetic testing for aneuploidies was associated with substantially lower rates of pregnancy loss. After the first embryo transfer, pregnancy loss occurred in 5.8% of couples in the testing group compared with 19.1% in the control group. Cumulative pregnancy loss was also lower, affecting 11.1% of couples compared with 22.7% among those who did not receive genetic testing.
The authors conclude that while embryo genetic testing may reduce miscarriages in this population, it does not improve live birth outcomes. They suggest that routine use of preimplantation genetic testing for aneuploidies for couples undergoing intracytoplasmic sperm injection solely because of severe male infertility should be reconsidered, with counselling focused on balancing lower pregnancy loss against unchanged live birth rates.
Reference
Lin X et al. Preimplantation genetic testing for aneuploidy versus no genetic testing in couples undergoing intracytoplasmic sperm injection for severe male infertility: multicentre, open label, randomised controlled trial. BMJ. 2025;391:e084050.
