The Centers for Disease Control and Prevention (CDC) reports that most men experience significant age-related fertility decline after they reach the age of 40 yrs.
Men typically never stop producing sperm, but there is a measurable decline in sperm quality as a man ages. The World Health Organization (WHO) has a set of benchmarks, known as semen parameters, for healthy sperm, including count, morphology (shape), and motility (movement). Starting around the age of 35, men may see their semen parameters worsen.
Paternal age is among the most significant factors affecting a couple’s chance of conceiving and their pregnancy outcomes. Men over the age of 35–40 typically experience a decrease in sperm health, which affects:
- Pregnancy rates. Pregnancy rates decrease with paternal age.
- Time to conception.
- Miscarriage risk. Pregnancy loss between the 6- and 20-week gestation period increases.
- Adverse pregnancy outcomes. Pregnancies that involve a male over the age of 45 see an increased risk of birthing complications
Offspring health risks.
The probability is still generally low but can pass genetic mutations to a child and increase their chances of developing a psychological or neurocognitive disorder.
Sperm motility is expected to decrease by about 0.8% per year of age. When comparing the sperm in men between the ages 30 to 35 with men over 55, sperm motility
Studies show that sperm morphology decreases by about 0.65% per year of age.
Sperm DNA fragmentation index refers to the amount of abnormal genetic material (damaged DNA) inside a sperm. The better your sperm quality, the lower this number should be. Studies show that sperm DNA fragmentation increases by 0.3% per year of age.