Sperm quality lowers with age
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.
Sperm quality diminishes after age 40
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.