Men Have a Biological Clock, too. This Is the Age That Heightens High-Risk Pregnancies, Birth Defects

Father Toddler Daughter Read Together
Father Toddler Daughter Read Together  Layland Masuda / Getty Images

For women, it’s well known that putting off having kids until middle age can be risky, both for their health and the health of their child. But men have never really been a part of that picture. Until now. New research suggests men need to be aware of their biological clocks, too.

Men who have children at the age of 45+ put their partners at risk for pregnancy complications, and their children have elevated risks of birth defects, childhood cancers, and other health issues, according to a study published in Maturitas. Researchers reviewed 40 years worth of studies on how parental age affects fertility, pregnancy, and a child’s well-being over time.

The findings come at a time where more and more men are delaying having children. The number of infants born to fathers over 45 has risen 10 percent in the U.S. over the past 40 years. To address the impacts of this trend, the study focused on three main risk areas: fertility, pregnancy, and children’s health. The researchers found that men 45 and older can experience decreased fertility, and if they decide to have children, their partners may experience a higher risk of pregnancy complications such as gestational diabetes and premature birth. The data also showed that their children had a higher risk of issues like low scores on the Apgar test (a basic examination used to assess a baby’s heart rate, breathing, and overall health), low birth weight, congenital heart disease, and cleft palate.

The potential issues continued as the children grew up. Children born to older fathers had an elevated risk for several other mental and physical health problems, including childhood cancers, psychiatric and cognitive disorders, and autism.

Bachmann points to the natural process of aging as the root cause of most of these issues, although she cautions that more research is needed to really clarify how they’re all related. As men get older, their testosterone levels decline, and the quality of their sperm and semen starts to degrade as well, which helps explain the fertility issues older men often deal with. In addition, aging can cause genetic changes in male sperm, and these mutations may explain the correlation between high paternal age and increased risk of health issues in their children.

Overall, the study illustrates the importance of understanding how fertility changes with age, regardless of gender.

“Women tend to be more aware and educated than men about their reproductive health,” says study author Gloria Bachmann, director of the Women’s Health Institute at Rutgers Robert Wood Johnson Medical School. “Most men do not consult with physicians unless they have a medical or fertility issue.”

But this doesn’t mean you have to have kids while you’re young, researchers say. Sperm banks provide another option. The researchers recommend men who want to delay fatherhood should bank their sperm before they turn 35, which should mitigate the risks to their partner and child.