Clarke Gary N, Stewart Tanya, Baker H W Gordon
Andrology Unit, The Royal Women's Hospital and Department of Obstetrics and Gynecology, Melbourne University, Melbourne, Victoria, Australia.
Reprod Med Biol. 2004 Dec 3;3(4):211-216. doi: 10.1111/j.1447-0578.2004.00073.x. eCollection 2004 Dec.
To compare sperm counts for two groups of men who had presented for infertility investigations approximately 20 years apart. The study compared results for 309 men tested between 1977 and 1981 with those of 559 men tested between 1997 and 1998 using identical methodology. In order to approximate the normal population, only those men with counts above 5 million/mL were included in the final analysis. Bias, due to repeated testing after an initial abnormal result, was minimized by including only the patient's first test results. In addition, to allow for time-dependent changes in the requirements for semen samples, results were included only if a complete sample was produced by masturbation after 3-5 days abstinence. There was a small, but statistically significant drop in ejaculate volume (3.9-3.6 mL, = 0.015) and a significant increase in the patient's mean age (32.18 vs 35.08, < 0.001). Both groups had median abstinence of 3 days and no difference in sperm counts with a mean (median) count for the early group of 87.9 (75) versus 92.0 (76) for the recent group ( > 0.80). The significant drop in ejaculate volume was not reflected in a difference ( = 0.45) in total sperm numbers in the ejaculate with 320.7 (255) versus 313.1 (234). This study found no evidence of a decrease in sperm counts or total sperm output in men (excluding those with severe oligospermia) presenting for infertility investigations in Melbourne, Australia, over the last two decades of the twentieth century. (Reprod Med Biol 2004; : 211-216).
为比较两组间隔约20年前来进行不孕不育检查的男性的精子计数。该研究使用相同方法，将1977年至1981年间接受检测的309名男性的结果与1997年至1998年间接受检测的559名男性的结果进行了比较。为了接近正常人群，最终分析仅纳入精子计数高于500万/mL的男性。由于初始结果异常后重复检测导致的偏差，通过仅纳入患者的首次检测结果而降至最低。此外，为考虑精液样本要求随时间的变化，仅当在禁欲3 - 5天后通过手淫获得完整样本时，结果才被纳入。射精量有小幅但具有统计学意义的下降（从3.9 mL降至3.6 mL，P = 0.015），患者平均年龄有显著增加（32.18岁对35.08岁，P < 0.001）。两组的禁欲时间中位数均为3天，精子计数无差异，早期组的平均（中位数）计数为87.9（75），近期组为92.0（76）（P > 0.80）。射精量的显著下降并未反映在射精总量的差异上（P = 0.45），分别为320.7（255）和313.1（234）。本研究未发现20世纪最后二十年在澳大利亚墨尔本前来进行不孕不育检查的男性（不包括严重少精子症患者）精子计数或总精子输出量下降的证据。（《生殖医学与生物学》2004年； ：211 - 216）
