A new international study presented today at the 41st Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) reveals that IVF cycles involving male partners over the age of 45 carry significantly increased miscarriage risks and lower live birth rates – even when young donor eggs are used.
PARIS, June 30, 2025 /PRNewswire/ -- By isolating paternal age from female reproductive factors through the exclusive use of donor eggs from young women, the study provides robust evidence that male age plays a critical role in reproductive success, challenging the common assumption that sperm age has little impact once fertilisation occurs.
The retrospective study analysed 1,712 first oocyte donation cycles conducted between 2019 and 2023 across six IVF centres in Italy and Spain. All cycles used fresh donor oocytes and frozen sperm from male partners, with only the first single blastocyst transfer included. Female recipients had a mean age of 43.3 years.
Participants were divided into two groups: men aged 45 or younger (n=1,066) and those over 45 (n=646). While fertilisation rates and embryo development were comparable between groups, significant differences emerged in clinical outcomes.
Miscarriage rates were notably higher among couples where the male partner was over 45, reaching 23.8% compared to 16.3% in the younger paternal age group. Similarly, live birth rates were significantly lower in the older paternal age group, at 35.1% versus 41% for men aged 45 or younger.
Discussing the findings, Dr. Maria Cristina Guglielmo, Embryologist at Eugin Italy, said, "Traditionally, maternal age has been the central focus in reproductive medicine, but our results show that the age of the male partner also plays a crucial and independent role. Even when using eggs from young, healthy donors and transferring only a single, high-quality embryo, we observed poorer outcomes in men over 45."
She also emphasised the importance of examining how paternal age affects the health of offspring. "There is growing evidence linking advanced paternal age to an increased risk of neurodevelopment disorders in children. Our future work will investigate the long-term health and developmental outcomes of children conceived through donor egg cycles with older fathers, where maternal factors are minimised, to isolate paternal effects more clearly."
The study abstract will be published today in Human Reproduction, one of the world's leading reproductive medicine journals.
