It’s widely known by many that a woman’s fertility takes a hit around the age of 35. By the age of 30, 90% of a woman's eggs are depleted in their ovaries, and by 40 years old, 97% of their eggs are gone. The ones that remain are not as healthy, leaving women at risk of having babies with genetic abnormalities or miscarriage.
The concept of the biological clock has been most associated with women. However, research shows it is not exclusive to women and men’s fertility also has a great deal to do with their age. In fact, a man’s age can have a significant effect on pregnancy and the health of the baby.
The European Society of Human Reproduction and Embryology meeting in Geneva in July 2017 found that some women benefited from being with a younger man. When women aged between 35-40 partnered with men aged 30-35, their chances of having a baby was 54%, and their chances rose to 70% when the man was under 30.
Women's biological clock has been a topic of discussion since the late 70's, and the cultural expression has been used since. However, the idea that a man would have a biological clock was far less accepted and quite laughable to some men who refused to accept that their testosterone levels could ever decline.
However, in the last decade or so, research has revealed the male biological clock exists, and it can affect fertility in 3 major ways. The first is that older fathers have a harder time conceiving. Secondly, pregnancies fathered by older men are more likely to result in miscarriages. And lastly, the age of the father affects the health of the baby; the younger the father, the less likely the baby is to have abnormalities.
It’s true that men produce sperm throughout their whole lives. However, with age comes a decrease in libido and erectile dysfunction. There’s also the matter of a decline in the quality and quantity of sperm.
If the ticking of the biological clock starts to get louder for women at age 35, it’s a little later for men. It appears that the changes appear to happen in their 40s and 50s. However, as a man ages, so does his sperm. In fact, the American Society for Reproductive Health recommends that sperm donors should "ideally be less than 40 years of age to minimize the potential hazards of aging."
But while the biological clock applies to both men and women, the problem lies in societal differences. Women feel more pressure to have babies sooner than men do. Nosy relatives and eager-to-be-grandparents are less likely to pressure the men they know about starting a family when they turn 35. The misconception remains that age-related fertility concerns are predominantly a female issue.
Harvard Medical School and Beth Israel Deaconess Medical Center revealed their study on the impact of a man’s age and its effect on naturally conceiving.
Dr. Laura Dodge, a lead author of the study, said, “The impact of age seems to focus almost exclusively on the female partner’s biological clock … When making this decision, [couples] should also be considering the man’s age.”
The study looked at 19,000 IVF cycles performed between 2000 and 2014 in an in vitro fertilization center in Boston. The couples were categorized by age, and the results clearly show that a man’s age is a predictor of success of IVF. The older the men were, efficacy rates dropped.
And in another research, scientists at the University of Copenhagen found that children born to older fathers had an increased risk of developing autism, prompting them to remark, “This reminds us that it takes two to tango and it’s not just down to the age of the woman.”