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Tick Tock — There's a Male Biological Clock
It's good to know women aren't the only ones battling the biological clock. A recent study in mice found that sperm from middle-aged and older male mice are less likely to lead to a successful pregnancy.
Researchers at the Colorado Center for Reproductive Medicine (CCRM) in conjunction with the National Foundation for Fertility Research found that for mice, sperm quality began to decrease in males at mid-life (12 months and older). This is equivalent to 40 and older for humans.
"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,'" says William Schoolcraft, M.D., founder and medical director of CCRM. "Men in their 30s should consider freezing sperm if they plan to wait to have children. Men in their 40s and 50s should consult a reproductive endocrinologist if their partner is unable to conceive after six months of active trying."
The researchers investigated 10 young male mice with proven fertility. As they naturally aged, the mice were mated every month during their lifetimes with fertile young females. The researchers were able to remove infertility related to female aging from the equation, and they found that when fertile male mice reached mid-life:
- Eggs were less likely to be fertilized by aged sperm.
- Embryos were less likely to develop in vitro.
- Embryos were less likely to implant in the uterus.
- There were far fewer pregnancies achieved naturally. Only 50 percent achieved pregnancy naturally at 12 months (40s) and 10 percent naturally at 15 months (50s).
- Assisted reproductive technologies (ART) improved the chance of clinical pregnancy.
- The natural pregnancies created with aged sperm resulted in significantly smaller fetuses and placental weight.
In a Brazilian study, researchers analyzed the outcome of 570 IVF treatments carried out at a clinic between March 2008 and April 2011, including only cases in which the eggs were donated by young, healthy women. The results showed that the age of men in the group that did not conceive was significantly higher than the age of those who were able to have a baby and revealed that when the husband was 41, the couple had a 60 percent chance of getting pregnant. By age 45, the chances of getting pregnant were down to 35 percent and dropped sharply thereafter.
So it's not just women who need to egg freezing before they get well into their 30s — men may need to think about freezing their swimmers if they are still waiting on Mrs. Right.