Male Age and Fertility
It's common knowledge that the age of a woman affects her ability to conceive. Egg quality diminishes as women get older. Pregnancy can be challenging to achieve if the woman is past 35 years old even if she takes advantage of the artificial reproductive technologies available like in vitro fertilization.
There's a great deal of literature written about the age of women and fertility, but very little (in comparison) available about the impact a man's age has on his fertility. One may begin to wonder: Is a man forever fertile?
Sperm Studies and Male Age
Although not much is available in mainstream media about the connection between a man's age and his fertility, numerous studies have been done on the topic. The University of California, School of Public Health conducted a study in 2003 to "characterize the association between age and semen quality. The study was published in the US National Library of Medicine in the National Institutes of Health.
The study collected samples from 97 non-smoking men from between the ages of 22- and 80-years-old. None of the men had known fertility problems. Each man provided a semen sample as well as information about his diet, occupation, lifestyle and medical history. Total sperm count, sperm concentration, sperm mobility and sperm volume were all measured.
The study concluded that the volume of the semen decreased by 0.03 ml per year. Motility decreased by 0.7 percent per year and progressive motility decreased by 3.1 percent per year. The researchers at the U of C School of Public Health concluded that there was a "suggested decrease in sperm concentration and count."
Another study, conducted at the Soroka University in Israel also looked into the effect of age on male sperm quality. The participants were all normal, healthy men who divulged personal information about their health and their sex lives along with their semen samples. (This study included information about sexual abstinence. There is a scientific connection between semen quality and the frequency of sexual intercourse.)
The Soroka University Study concluded that semen quality peaked between the ages of 30 and 35. Semen quality was lowest after 55. The speed at which the sperm swim (sperm motility) was best before the age of 25, according to the study, and lowest after 55 years old. Sperm motility decreased by 54 percent in men over the age of 55 compared to men in the age bracket of 30 to 35.
Some might argue that older men have less frequent sex which can eventually lead to low quality sperm. Because this study also tracked sexual activity, this reason for lower quality sperm was eliminated.
Genetic Defects and the Age of Male Sperm
A study done at the Lawrence Livermore National Laboratory (LLNL) and the University of California at Berkeley showed increased genetic quality in sperm as a man gets older. The conclusion of the study is that older men are likely to pass on genetic problems to their offspring and that older sperm can increase the chance of some birth defects and the risk of miscarriage.
Men's Age and IVF
Another study done by the Assuta Medical Center in Rishon, LeZion, Israel found a link between IVF success rates and the age of the biological man. In many cases, women over 40 who get pregnant using IVF use donor eggs and their partner's sperm so all participants in this study used donor eggs. The study showed that the outcome of the procedure was also impacted by the age of the partner.
According to the study, any amount of decreasing in sperm quality didn't have a significant effect on the IVF procedure up until the age of 40. After 40 the sperm quality began to diminish significantly and this was connected to possible IVF treatment failure. IVF embryos created with sperm of a man over 40 and an egg from a woman under 35 were found to be of lower quality in the study.