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Men's Biological Clocks are Ticking, Too
Evidence is piling up that men, or at least our reproductive parts, have a "best before" date. Not only is it harder to create a pregnancy after the age of 35 or 40, researchers are finding that our sperm quality decreases with age. This can result in a higher-than-normal incidence of offspring with schizophrenia, autism and low IQ, as well as an increased chance of miscarriage.
Quite a few experts are calling for more awareness of this problem, partly to balance out the "grandpa-daddy" trend among high-profile celebrities. Yes, Celine Dion, 41, is pregnant and her husband Rene is 67. Sure, actor Anthony Quinn became a father at age 81 and Charlie Chaplin was able to mock his biological clock at age 73. Pierre Trudeau's last child was born when he was 72.
Still, for most of us, baby making is a game best played by the young. A study of more than 12,000 couples treated at the Eylau Centre for Assisted Reproduction in Paris found a man's fertility drops off in his late 30s and plummets after 40. The researchers also found if the father was over the age of 44, almost a third of the pregnancies ended in miscarriage.
They attribute this at least in part to a kind of "sperm decay," marked by DNA fragmentation and other abnormalities. Unlike women, who are born with all their eggs, men do not make any sperm until they reach puberty. Then we make up for it by generating up to 100 million new ones per day. Because of all this sperm-copying, mutations can accumulate with age.
Writing on healthline.com,fertility specialist Dr. Carl Herbert likens the process to photocopying a cake recipe over and over until the "3 cups of flour" looks like "2 cups" and the recipe doesn't work any more.
"These subtle copying defects cause a long list of diseases in the children of older fathers," he writes. "Lesch Nyhan syndrome, polycystic kidney disease and hemophilia A are among the most well known. For fathers over age 40, the risk of having a child with a disease-causing mutation is similar to the risk the mother has for a child with Down syndrome." Other factors, ranging from high or low body weight to diabetes, can also adversely affect sperm quality.
Columbia University urologist Dr. Harry Fisch is one of the high-profile experts speaking out about the risks of geriatric fatherhood. He's appeared on the Today show and written a book called The Male Biological Clock, as well as an article in the medical journal Geriatrics. There he warns "couples are waiting longer to have children, and advances in reproductive technology are allowing older men and women to consider having children. The lack of appreciation among both medical professionals and the lay public for the reality of a male biological clock makes these trends worrisome."
Since there's no turning back our biological clocks, Fisch advises older dad-wannabes to "have a thorough history and physical examination focused on their sexual and reproductive capacity. Such examination should entail disclosure of any sexual dysfunction and the use of medications, drugs, or lifestyle factors that might impair fertility or sexual response."
Other experts suggest older couples trying for a baby should at least consider an assisted reproductive technology such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI.) IVF is the classic "test tube baby," fertilized outside the body and implanted in a uterus.
ICSI is a fancier technique that involves injecting a specific sperm into an egg, again outside the woman's body. While there's no guarantee that a spermatozoon that looks good during this procedure will be genetically sound, at least the duds with two heads or two tails can be eliminated. Contrarians argue that piercing the egg with a needle might allow a sperm that should never succeed to penetrate the egg. With these procedures, you pay thousands of dollars and you still take your chances.
One cheerful bit of sperm news was presented in July at the European Society of Human Reproduction and Embryology meeting. Australian researcher Dr. David Greening reported that having sex (or at least ejaculating) every day improved sperm DNA quality.
He studied 118 men with higher-than-normal sperm DNA damage and instructed them to ejaculate daily for seven days. He found this somewhat pleasant prescription produced a significant reduction in DNA-damaged sperm. Asked why this happened, he suggested the sperm spent less time in the male plumbing system, where they can be exposed to DNA damage.
A blurb on the back cover of Harry Fisch's book notes "male sexuality is a topic discussed far more by standup comics than by responsible physicians." Which, of course, leads to the classic "Why does it take millions of sperm to fertilize one egg? Because they won't ask for directions."
Now it seems that, as we get older, this little jest becomes even more appropriate!
Tom Keenan, I.S.P., is an award-winning science writer, professional speaker and professor at the University of Calgary. He welcomes your questions at firstname.lastname@example.org. When sending an e-mail, please insert 'Attention Tom Keenan' in the subject line.