The meta-regression used 244 estimates from 185 studies of 42,935 men providing samples in 1973–2011. Among unselected Western studies, mean sperm concentration declined 52.4% and total sperm count declined 59.3%; no significant trends appeared in the “Other” geographic groups.
Trends for TSC and SC were similar, with a steep decline among Unselected Western (-5.33 million/year, -7.56 to -3.11; P < 0.001), corresponding to an average decline in mean TSC of 1.6% per year and overall decline of 59.3%.
The meta-regression used 244 estimates from 185 studies of 42,935 men providing samples in 1973–2011. Among unselected Western studies, mean sperm concentration declined 52.4% and total sperm count declined 59.3%; no significant trends appeared in the “Other” geographic groups. The correct journal is Human Reproduction Update 2017;23(6):646–659, not Scientific Reports. “Western” means North America, Europe, Australia, and New Zealand. it does not identify a specific chemical cause.