A Danish Study found that men of parents who were diagnosed with subfertility levels, had lower sperm counts and fewer normal looking sperm. The study authors concluded that at least some causes of infertility are hereditary. 311 Danish men were studied, ages 18-21 and those with parents who took longer than one year to conceive were more likely to have sperm issues. It could be a combination of lifestyle factors, such as nutritional and fitness factors that are passed from generation rather than simple physical hereditary factors. Visit Keithconnectsthedots to learn more.