Cross SectionalHumann = 2,4302025Italy
Obesity has a detrimental impact on temporal decline of sperm quality in normospermic patients: insights from a cross-sectional study of 2,430 patients over 14 years.
Plain-language summary
This study looked at whether obesity speeds up the decline in sperm quality that has been seen over time. Researchers reviewed semen tests from 2,430 men with normal sperm counts evaluated between 2010 and 2024, grouped them by weight, and tracked how sperm count, movement, volume, and shape changed across that 14-year span. Sperm quality drifted down over the period for every weight group, but the drop was steepest in men with obesity, especially in total sperm count and volume. Even normal-weight men showed some decline across the years, so this is a broad downward trend over time that carrying extra weight makes worse.
Key findings
- Higher BMI correlated with declines in sperm quality in normal sperm men.
- Normal-weight men showed decreases in total sperm count, motility, volume, and morphology.
- Overweight men had reductions in sperm motility and volume.
- Obese men exhibited significant declines in total sperm count and semen volume.
How to analyze the study yourself
- Study type
- Cross-sectional studies are good at identifying associations at a single point in time but cannot establish cause and effect.
- Population
- The study included men with normal sperm counts.
- Funding
- Not reported
- Watch for
- This study found that sperm quality has been sliding over time across the board, and that men with obesity had the steepest drop. The decline showed up over the 14-year window, not from any single weight change. If fertility is a concern, keeping a healthy weight looks like one lever that slows the slide.