Health · Medical Research · 1 hr ago
Study compares reproductive health in 117 father-son pairs
Researchers in Finland and Denmark compared reproductive traits in 117 father-son pairs.
The sons were aged 18 to 23, and the fathers had a median age of 52.2.
The study examined sperm, reproductive hormones and physical traits, against a background of declining fertility rates in several countries and concerns about semen quality.
Fathers had larger testes and higher sperm counts and concentrations than their sons.
Fathers also had lower total and free testosterone, while sons were more likely to have smoked daily in the previous three months.
The findings show differences between these generations, but the study does not establish what caused them.
Researchers compared reproductive traits in 117 father-son pairs from Finland and Denmark.
The study examined semen measures, reproductive hormones and physical characteristics.
Fathers had higher total sperm counts and sperm concentrations than their sons.
Fathers also had higher FSH and SHBG levels, lower testosterone levels and larger testes.
The study investigated how closely reproductive traits resemble those of fathers and sons.
- Who
- Researchers studied 117 father-son pairs from Finland and Denmark.
- What
- The study compared reproductive traits, including semen measures, hormone levels and testicular characteristics.
- When
- The sons were born during 1997–2002 and attended follow-up visits with their fathers during 2017–21. The study was published on 22 October 2026.
- Where
- Finland and Denmark.
- Why
- To investigate how closely men's reproductive characteristics resemble those of their fathers.
This story does not have two clearly opposing sides.
The sons in the Finnish-Danish Boy birth cohort were born.
Sons aged 18–23 attended follow-up visits with their fathers.
The study was published in Andrology.
- Father-son pairs
- 117 total: 79 from Denmark and 38 from Finland
- Median age
- Fathers: 52.2 years; sons: 19.6 years
- Birth cohort
- Sons born in 1997–2002
- Follow-up visits
- 2017–21
- Sperm concentration
- Below 1 million/mL for five participants; below 15 million/mL for 23 additional subjects