Latest research suggests a male biological clock

Colorado Researchers Confirm Men, like Women, have a Ticking Biological Clock that Impacts Fertility

A new study conducted by the Colorado Center for Reproductive Medicine (CCRM) in conjunction with the National Foundation for Fertility Research (NFFR) concludes that sperm from middle-aged and older male mice is less likely to lead to a successful pregnancy. The study, the first-of-its-kind, found that sperm quality began to decrease in males at mid-life, 12 months and older (equivalent to forty and older for human males).

This study found that when proven fertile male mice reached mid-life (12 months = forties in human male):

1. Eggs were less likely to be fertilized by aged sperm.

2. Embryos were less likely to develop in vitro.

3. Embryos were less likely to implant in the uterus.

4. Natural conceptions were far fewer. Only 50 percent achieved pregnancy naturally at 12 months (forties) and 10 percent naturally at 15 months (fifties).

5. Assisted reproductive technologies (ART) improved the chance of clinical pregnancy.

6. The few successful natural conceptions with aged sperm resulted in significantly smaller fetuses and placental weight.

"There is much focus in society on the 'maternal biological clock.' This study shows us that we also need to be concerned about the 'paternal clock,'" said William Schoolcraft, M.D., Founder and Medical Director of CCRM. "Men in their thirties should consider freezing sperm if they plan to wait to have children. Men in their forties and fifties should consult a reproductive endocrinologist if their partner is unable to conceive after six months of active trying."