Normal reference ranges for semen quality and their relations to fecundity

Several recent studies have shown that the fecundity of a man decreases progressively with sperm concentrations below 40 million spermatozoa per mL. Therefore, it is unfortunate that the new World Health Organization guidelines for semen analysis recommend lowering the lower cutoff value for normal sperm concentration from 20 to 15 million spermatozoa per mL. As a result large groups of subfertile men across the world may not receive appropriate andrological help in the future.

精液质量的正常参考值与男性生育能力

最近的研究表明:如果男性精液中精子密度低于40×106/mL,其生育能力就会随精子密度减少而相应下降。然而最新出版的《世界卫生组织人类精液分析实验室技术手册》第5版将正常精液密度的下限值,从原来的20×106/mL降低到15×106/mL。鉴于这一改动,全世界很大一部分生育能力低下的男性,将被认为"正常"而得不到适当的男科治疗。

精液质量下降趋势:近50年观

目的研究近50年来男性精液质量是否发生变化。设计研究方法通过检索Cumulated Index Medicus and Current List(1930-1965年)和MEDLINE Silver Platter database(1966-1991年8月),纳入无不育病史男性的精液质量的相关文献进行回顾分析。研究对象纳入1938-1991年间发表的61篇文献中共14947名男性。