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Sperm counts of men in North America, Europe, Australia and New Zealand are plunging, according to a new analysis published Tuesday.
Among these men there has been a 52% decline in sperm concentration and a 59% decline in total sperm count over a nearly 40-year period ending in 2011, the analysis, published in the journal Human Reproduction Update, said.
Scientists determine sperm count by looking at a sample of ejaculate under a microscope. For sperm concentration, they measure how many millions of sperm there are in each milliliter of fluid. Sperm count, then, is sperm concentration multiplied by the total volume of an ejaculate.
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