Many environmental contaminants are potentially toxic to eggs and sperm and there are increasing numbers of men and women of late reproductive age, who are having difficulty producing a sufficient number of good gametes to conceive. The evidence suggests that fertility is influenced by lifetime exposure, probably at very low levels to oxidative stress via reproductive toxicants.
In addition, despite antibiotic treatment, early life exposure to immune challenges suggest that increased proinflammatory signalling within the neonatal gonads may be responsible for the depletion of the primordial follicle pool and spermatogenic dysregulation. These findings also have implications for late female and male fecundity as major determinates of reproductive longevity.