Male Biological Clock Puts Children at Risk

Reviewed By:
Rafiu Ariganjoye, M.D., MBA, FAAP

Women aren't the only ones with ticking biological clocks. There's growing evidence that children of aging fathers face increased risk of many diseases and even premature death. But the good news is that there are ways to reduce this risk.

The most starting finding: Children fathered by middle-aged men (45 or over) are nearly twice as likely to die before adulthood. This comes from a 2008 study of about 100,000 Danish children born between 1980 and 1996.

Even after adjusting for the mother's age and other factors, researchers found an increased risk of death for children of older fathers. The mortality rate for children of men 45 and older was almost double that of children fathered by men in their late 20s. Children of teenage fathers also had higher mortality rates, but that was blamed on other factors such as poverty and the risks of teen motherhood.

Birth defects and injuries were leading causes of the greater mortality in the older men's children. The researchers speculated that the injuries may be related to conditions such as autism, schizophrenia or epilepsy. The study was published in the European Journal of Epidemiology.

As men age, fertility declines because the quantity and genetic quality of sperm decreases. In recent years, scientists have linked aging sperm to higher risk of diseases in offspring including Down syndrome, certain other congenital disorders, autism, schizophrenia, epilepsy and possibly cancer, Alzheimer's disease, multiple sclerosis and type 1 diabetes.

Health risks associated with mother's age are more generally known, which is why experts are working to make more people aware that the father's age increases risk too. One of those experts is Harry Fisch, MD, a specialist in male fertility and professor at Columbia University Medical Center at New York Presbyterian Hospital.

"It has long been known that a woman's chance of having a baby with Down syndrome rises dramatically after age 35, but it had been thought that the man's age had nothing to do with it. Now we know that this is false--men also have a higher likelihood of fathering a Down syndrome baby as they get older," writes Dr. Fisch in his book The Male Biological Clock.

If you're nearing your 40s and thinking of having kids, remember that a risk factor only means that something has an above-average chance of happening--not that it will definitely happen. The majority of older fathers and mothers have healthy children, and you can take steps to lower certain risks. Consult your doctor if you have concerns.

Positive actions

Is there any way to slow the biological clock and boost the chances of fathering a healthy child? It's a myth that the quality and quantity of sperm can't be improved, according to Dr. Fisch. He suggests that men:

Get regular, moderate exercise
Eat a nutritious diet
Avoid things that can damage sperm, including cigarettes, anabolic steroids and hot tubs

In addition, pregnancies that are planned have a reduced risk of birth defects. It's important for mothers to follow through with all the prenatal care recommended by their doctor, such as having regular checkups, taking folic acid (a B vitamin) and not smoking or drinking any alcohol. Higher-risk parents may also wish to consider genetic counseling and, where appropriate, genetic testing or assistive reproductive technology.

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