What role does BDNF play in fertility?

BDNF (Brain-Derived Neurotrophic Factor) is best known for its role in neuroplasticity, but it also plays a significant role in fertility. It is expressed in the ovaries, endometrium, and sperm, and influences oocyte maturation, embryo implantation, and sperm quality. Observational studies suggest that lower BDNF levels may be associated with fertility issues such as endometriosis or recurrent miscarriage. However, the evidence is primarily observational and mechanistic; direct clinical recommendations for measuring or supplementing BDNF to improve fertility are not yet supported by robust trials. Genetic variants like BDNF Val66Met (rs6265) are sometimes included in consumer DNA tests, but their impact on fertility is small and not actionable. Blood or saliva BDNF testing is not standard in fertility workups. A healthy lifestyle with regular exercise, adequate sleep, and omega-3 fatty acids can support BDNF levels, which may indirectly benefit fertility. Evidence is rated human-moderate due to the lack of randomized controlled trials targeting fertility outcomes.