Zinaman M J, Brown C C, Selevan S G, Clegg E D
Department of Obstetrics and Gynecology, Georgetown University Medical Center, Washington, DC, USA.
J Androl. 2000 Jan-Feb;21(1):145-53.
Measures of semen quality are used as surrogate measures of male fertility in clinical andrology, reproductive toxicology, epidemiology, and risk assessment. However, only limited data are available to relate those measures to fertility. This prospective study with 210 reproductive-age couples was conducted to provide information on the value of semen quality measures for predicting human male fertility potential and for development of models to estimate the effects of changes in semen quality on fertility in a given population for risk assessment. Couples without known risk factors for infertility and who had discontinued contraception to have a child were accepted. The study followed each couple for up to 12 menstrual cycles while they attempted to conceive and evaluated semen quality measures from multiple ejaculates per man with known abstinence intervals. For each cycle, the day of ovulation was predicted, and the couple was advised to have intercourse multiple times on that day and on the days around it. Among the demographic variables assessed, parity, contraception status prior to entering the study, male education level, and male smoking were associated significantly with 12-cycle pregnancy rate. Several semen quality measures also were associated significantly with pregnancy rate, with percentage morphologically normal sperm by strict criteria and measures involving total number of sperm showing particularly strong associations. Localized regression-smoothing plots of semen quality data against proportion of couples pregnant suggested levels below which fertility declines for several semen quality measures. These results have applications in both clinical andrology and in assessment of risk to male fecundity from environmental or pharmaceutical exposures. In particular, they contribute information on behavior of fertility with varying semen quality and can allow development of models to predict effects on fertility in populations from decrements in semen quality.
在临床男科学、生殖毒理学、流行病学及风险评估中，精液质量指标被用作男性生育能力的替代指标。然而，将这些指标与生育能力相关联的数据却十分有限。本前瞻性研究纳入了210对育龄夫妇，旨在提供有关精液质量指标在预测男性生育潜力方面的价值信息，并建立模型以评估精液质量变化对特定人群生育能力的影响，用于风险评估。纳入标准为无已知不孕风险因素且已停止避孕准备生育的夫妇。研究对每对夫妇进行了长达12个月经周期的随访，期间他们尝试受孕，并对每名男性在已知禁欲间隔下多次射精的精液质量指标进行评估。对于每个周期，预测排卵日，并建议夫妇在该日及其前后几天多次性交。在评估的人口统计学变量中，产次、进入研究前的避孕状况、男性教育水平和男性吸烟情况与12周期妊娠率显著相关。多项精液质量指标也与妊娠率显著相关，其中严格标准下形态正常精子的百分比以及涉及精子总数的指标显示出特别强的相关性。精液质量数据与妊娠夫妇比例的局部回归平滑图表明，对于多项精液质量指标，低于某一水平时生育能力会下降。这些结果在临床男科学以及评估环境或药物暴露对男性生育力的风险方面均有应用。特别是，它们提供了不同精液质量下生育能力表现的信息，并有助于建立模型以预测精液质量下降对人群生育能力的影响。
