GoodGirlsGetGutted wrote:Good call.
Semen quantity peaks between the ages of 30 and 35, while overall semen quantity is found to be lowest after age 55. Sperm motility, in other words, how well the sperm swim, is best before age 25 and lowest after age 55. In fact, when comparing the number of “good swimming” sperm in men between the ages 30 to 35 with men over age 55, sperm motility decreased by 54%. These strong variations can not be blamed on sexual abstinence (In other words, the lower quality semen in the older men could not be blamed on infrequent sex, which can also lead to low-quality sperm.)
Besides low-quality semen, age also affects the genetic quality of male sperm. Genetic defects in sperm increase with age in men, possibly leading to decreased fertility, increased chance of miscarriage and increased risk of some birth defects. The scientists reported that older men are not only at risk for infertility, but they are also more likely to pass on genetic problems to their children.
"What is the risk of birth defects in babies of women over 35?
The risk of bearing a child with certain chromosomal disorders
increases as a woman ages. The most common of these disorders is Down
syndrome, a combination of mental retardation and physical
abnormalities caused by the presence of an extra chromosome 21 (humans
have 23 pairs of chromosomes). At age 25, a woman has about a
1-in-1,250 chance of having a baby with Down syndrome; at age 30, a
1-in-1,000 chance; at age 35, a 1-in-400 chance; at age 40, a 1-in-100
chance; and at 45, a 1-in-30 chance."
I think it's both

But we digress
