Male fertility and sperm quality generally peak in a man's 20s and early 30s.
While men can father children later in life, a gradual decline in sperm motility (movement), morphology (shape), and DNA integrity typically begins around age 35, with more pronounced reductions often occurring after age 40 to 45.
Key Sperm Parameters by Age:
Age 20s to Early 30s: This is the period of peak male fertility. Sperm count, motility (swimming ability), and the percentage of normally shaped sperm are generally at their highest.
Age 35–40: Semen volume and the percentage of active, properly shaped sperm begin to decrease. Sperm can take longer to swim to an egg, which increases the time it takes to conceive.
Age 40–45: Men in this age bracket see a more rapid decline in total sperm count and morphology. The likelihood of sperm DNA fragmentation (damage to the genetic code) rises significantly, which can lead to higher rates of miscarriage and a slight increase in certain genetic conditions in offspring.
Age 50+: Men over 50 are significantly more likely to present with anomalous semen volumes and lower overall sperm counts compared to younger males.
Factors Impacting Sperm Health Over Time:
Unlike women, who are born with a fixed number of eggs, men produce new sperm continuously. However, because sperm stem cells continually divide and replicate as a man ages, the risk of genetic damage and mutations increases.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6993171/
Varför skulle unga kvinnor vilja ha en slöa spermier som orsakar missfall och som ger ökad risk att barnet får genetiska defekter?