Everyone knows about a woman’s biological clock. It stops ticking at menopause, and along the way, it can make conceiving increasingly difficult (these are the factors that affect fertility). But when it comes to fertility, men have a biological clock too—and their age is especially important in couples where the woman is older than age 30. Those are the findings from a group of researchers led by Laura Dodge, ScD, of the Beth Israel Deaconess Medical Center and Harvard Medical School in Massachusetts, in a study presented at the 33rd Annual Meeting of the European Society of Human Reproduction and Embryology.
According to a statement by Dr. Dodge in the Science Daily, it is already well established in the scientific community that a man’s chances of getting his partner pregnant without a medical intervention such as in vitro fertilization (IVF) decrease with age. Dr. Dodge and her fellow researchers wanted to study the relationship between male age and fertility in couples undergoing IVF. Specifically, they studied 19,000 of them between the years 2000 and 2014, all of them at leading IVF centers in the Boston, Massachusetts area. The results show that male fertility drops with age, and this dynamic is especially evident where the age of the woman would not otherwise be a factor due to her biological clock (i.e., where the woman is under the age of 30).
In fact, couples in which the female partner was under age 30 had significantly lower IVF success rates if the man was older than 40 (the conception success rate was 46 percent in these couples), than if he was between 30 and 35 (the success rate was 73 percent in these couples).
Couples in which the female partner was 35 and older had 30 percent more success conceiving when the male partner was under the age of 30, as opposed to between the ages of 30 and 35 (live births increased from 54 percent to 70 percent with the younger men). Accordingly, it would appear that any woman can significantly increase her chances of conceiving via IVF by having a male partner who is younger than 35, and a woman aged 35 or older can increase her chances by having a male partner under the age of 30.
Although the reasons behind the age-related decline in male fertility are not completely clear, a previous study in the United Kingdom suggests it may be due to decline in sperm count and quality, an increase in DNA fragmentation, and a greater incidence of medical conditions that might affect fertility, such as heart disease and diabetes. Without clear evidence of why fertility drops off in men after a certain age, the “best preconception advice we can offer is to maintain a healthy lifestyle,” Dr. Dodge says.
If you’re a man interested in conceiving, here are the things you can do to boost your fertility.