The Sperm Epigenome, Male Aging, and Potential Effects on the Embryo

The effect of paternal aging on fertility, embryo quality, and offspring health is an important area of study that has received far less attention than the age effect in women. This is, in part, due to the fact that in females there are dramatic alterations to fertility and pregnancy outcomes that abruptly occur as a female ages. Such abrupt alterations to pregnancy success and/or embryonic and offspring health are not seen in males. Instead, there are subtle alterations to pregnancy success and offspring phenotypes that occur as a man ages. It is believed that, at least in part, these alterations can be explained by perturbations to the sperm epigenome that occur over time. This chapter will explore the effect of aging on the sperm epigenome and the potential impacts these perturbations may have on embryonic development and ultimately offspring health.