Age & male fertility

How testosterone declines with age

Testosterone declines gradually with age, starting at around 40 years old and at a rate of approximately 1% to 2% per year.
Revised on
July 16, 2026
Adult with arm around child's shoulders walking on outdoor basketball court holding a basketball.

Misconceptions about age and male fertility

Advanced paternal age reduces conception chances, while women may conceive more easily with younger partners.
Revised on
March 17, 2020
Adult with arm around child's shoulders walking on outdoor basketball court holding a basketball.

Paternal age and adverse birth outcomes

Scientists discovered that fathers pass more genetic mutations to offspring than mothers, a theory first proposed in the 1930s.
Revised on
March 17, 2020
The risk of genetic mutations with paternal age

The risk of genetic mutations with paternal age

Healthy sperm from older and younger men appear nearly identical under a microscope.
Revised on
March 17, 2020