Sripada Sreebala, Fonseca Sofia, Lee Amanda, Harrild Kirsten, Giannaris Dimitrios, Mathers Eileen, Bhattacharya Siladitya
Aberdeen Fertility Centre, Aberdeen Maternity Hospital, Aberdeen, Scotland, UK.
J Androl. 2007 Mar-Apr;28(2):313-9. doi: 10.2164/jandrol.106.000729. Epub 2006 Nov 1.
The data on trends in semen quality are conflicting and sensitive to geographical variations. Although previous British surveys on semen quality indicate a decline, the northeast of Scotland has never been included in these surveys. This is an area with low out migration rates where andrology services for a population of 500 000 are centralized within a single laboratory, thus providing a unique opportunity to study population-based trends in semen quality over time. We investigated trends in semen parameters between 1994-2005, in a cohort of 4832 men attending for routine semen analysis at the Aberdeen Fertility Centre who had a sperm density of greater than 20 million per mL. The main outcome measures were trends in sperm density, sperm motility and motile density in the first semen sample. Linear regression and time series analysis were used to examine trends over time in the semen parameters. The mean and standard deviation (SD) age of all men (n=5204) in the study was 34(6) years. The median (inter quartile range) for sperm density and motile density for the study population were 61 (40-91) million/mL and 99 (47-181) million. The mean (SD) sperm motility was 49 (19)%. Among 4832 men (with sperm count >20 million per mL), data adjusted for age and period of abstinence showed a decreasing trend for sperm density over time, R2=0.45 (P=.017). There was no such trend in sperm motility and motile density. However, this trend has to be interpreted with caution due to fluctuations in semen parameters, population bias and the retrospective nature of the analysis.
关于精液质量趋势的数据存在矛盾，且对地理差异敏感。尽管此前英国关于精液质量的调查表明精液质量有所下降，但苏格兰东北部从未被纳入这些调查。该地区人口外流率较低，为50万人口提供男科服务的机构集中在一个实验室，因此提供了一个独特的机会来研究基于人群的精液质量随时间的趋势。我们调查了1994年至2005年间，阿伯丁生育中心4832名接受常规精液分析、精子密度大于每毫升2000万的男性队列中的精液参数趋势。主要观察指标为首次精液样本中精子密度、精子活力和活动精子密度的趋势。采用线性回归和时间序列分析来检验精液参数随时间的趋势。研究中所有男性（n=5204）的平均年龄和标准差（SD）为34（6）岁。研究人群的精子密度和活动精子密度的中位数（四分位间距）分别为61（40 - 91）百万/毫升和99（47 - 181）百万。平均（SD）精子活力为49（19）%。在4832名（精子计数>每毫升2000万）男性中，经年龄和禁欲期校正的数据显示，精子密度随时间呈下降趋势，R2 = 0.45（P = 0.017）。精子活力和活动精子密度没有这种趋势。然而，由于精液参数的波动、人群偏差以及分析的回顾性性质，这种趋势必须谨慎解读。
