Fisch H, Goluboff E T
Department of Urology, Squier Urologic Clinic, Columbia-Presbyterian Medical Center, New York, New York 10028, USA.
Fertil Steril. 1996 May;65(5):1044-6. doi: 10.1016/s0015-0282(16)58284-3.
To determine whether geographic variations in sperm counts might bias conclusions drawn from studies of semen quality.
Reanalysis of published data from a meta-analysis of 61 studies from 1938 to 1990 that concluded a worldwide decline in semen quality over the last 50 years.
Influence of geographic location on sperm counts.
Of 61 studies in the meta-analysis, only 20 included > or = 100 men. These 20 studies collectively comprised 91% of the total men studied. We focused our reanalysis on these 20 studies. Of the studies before 1970, all were from the United States and 80% were from New York. These studies represented locations with the highest sperm counts. In contrast, after 1970, 80% of the studies were from locations not represented earlier, including five studies from third world countries, where sperm counts were low.
Sperm counts vary dramatically among different geographic locations.
确定精子计数的地理差异是否会使从精液质量研究得出的结论产生偏差。
对1938年至1990年61项研究的荟萃分析中已发表数据进行重新分析，该荟萃分析得出结论称过去50年全球精液质量呈下降趋势。
地理位置对精子计数的影响。
在荟萃分析的61项研究中，只有20项纳入了≥100名男性。这20项研究共涵盖了所研究男性总数的91%。我们将重新分析聚焦于这20项研究。在1970年之前的研究中，所有研究均来自美国，且80%来自纽约。这些研究代表了精子计数最高的地区。相比之下，1970年之后，80%的研究来自之前未涉及的地区，包括来自第三世界国家的五项研究，这些地区的精子计数较低。
不同地理位置的精子计数差异巨大。
