Yes, though the risk of having a child with a birth defect due to the father’s advancing age is hard to quantify and is probably “very tiny – a fraction of one percent,” said Dr. Aubrey Milunsky, director of the Center for Human Genetics at Boston University School of Medicine.
Still, the more researchers probe the genetic risk of birth defects, the more they are finding that it is not just a woman’s age that raises risk, but the man’s, too. “The age of the male does matter and the genetic quality of sperm does decline with age,” said Dr. Harry Fisch, professor of clinical urology at Columbia University Medical Center.
In birth defects associated with advancing maternal age, the problem is often with a whole chromosome. Down syndrome, for instance, occurs when the fetus gets an extra copy of chromosome 21, as occurs more often in women over 35.
With paternally-caused defects, the problem is usually a mutation in just one gene. Most diseases that pop up for the first time in a family are due to mutations in the DNA of the father, not the mother.
One reason is that, unlike eggs, sperm cells are constantly dividing to make more sperm. “Because this happens in men constantly, there’s more of a chance for mistakes to occur,” said Dr. Ethylin Wang Jabs, a geneticist at Johns Hopkins University.
In 2001, Dr. Dolores Malaspina, a Columbia psychiatrist, found that advancing paternal age accounted for as many as one in every four cases of schizophrenia. Other conditions associated with advancing paternal age include dwarfism, Marfan’s syndrome (which can lead to fatal rupture of a major blood vessel) and malformation of the skull, hands and feet. For more specific questions, it might be wise to consult a genetic counselor.