Statistic
−52%
Sperm concentration fell about 52% between 1973 and 2011
The largest meta-analysis of the question found sperm concentration among Western men declined by 52.4% between 1973 and 2011 — a real, ongoing fall, though its cause is unresolved and the "spermageddon" framing overstates it.
The number
Across the best-quality studies of men not selected for fertility problems, sperm concentration in North America, Europe, Australia and New Zealand fell 52.4% between 1973 and 2011 — about 1.4% a year. [1]
the mean SC declined, on average, 1.4% per year with an overall decline of 52.4% between 1973 and 2011
What it does and doesn't establish
The decline is real, large and — per the 2022 global update — ongoing and not confined to the West. What the figure does not settle is the cause (obesity, chemical exposures, measurement changes and selection are all debated) or the leap to a fertility "apocalypse": the measure is sperm concentration, not a demonstrated collapse in men's ability to father children. For the full argument, see the claim check is sperm count declining? and the underlying study, Levine et al. 2017.
Sources
1 source · all archived at publication
- [1]Temporal trends in sperm count: a systematic review and meta-regression analysis · Human Reproduction Update · 2017-11-01 archived ↗
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