Chia S E, Lim S T, Tay S K, Lim S T
Department of Community, Occupational and Family Medicine, National University of Singapore, Republic of Singapore.
BJOG. 2000 Jan;107(1):55-61. doi: 10.1111/j.1471-0528.2000.tb11579.x.
To determine the likely risk factors, such as smoking and drinking habits, and occupational groups, for infertility in a group of infertile men with no known cause, compared with a group of fertile men; and to examine the effects of the semen parameters, such as volume, density, motility, viability and normal morphology, on fertility.
A case-control study.
The department of obstetric and gynaecology of a tertiary general hospital.
Six hundred and forty consecutive male partners of couples trying to conceive were recruited from an infertility clinic. Of these, the cases comprised 218 men who had no known cause for their infertility. Two hundred and forty men whose wives were pregnant at the time of the study were recruited as controls.
The semen parameters (e.g. density, total sperm counts, motility, viability and normal morphology) of all cases were significantly poorer than that of the controls. The risk of infertility is associated with smoking (crude OR 2 x 82, 95% CI 1 x 93-4 x 13; adjusted OR 2 x 96; 95% CI 1 x 98-4 x 42). Technicians (adjusted OR 2 x 81; 95% CI 1 x 51-4 x 24) and professional, senior officials and managers were also at a greater risk of infertility (adjusted OR 2 x 36; 95% CI 1 x 26-4 x 40), compared with service and clerical workers. The significant factors predicting infertility were smoking, density of sperm, and viability of sperm. Smoking increased the odds of being infertile. Higher sperm counts and larger percentage of viable sperm decrease the odds of infertility. Based on the multiple logistic regression model, the odds ratio for infertility = (94 x 70) x (2 x 88(smoking)) X (0 x 29(logdensity)) X (0 x 95(viability)).
Smoking, density of sperm and the viability of sperm are significant predictors for infertility among men.
与一组生育能力正常的男性相比，确定一组不明原因不育男性中可能的风险因素，如吸烟和饮酒习惯以及职业群体；并研究精液参数，如精液量、密度、活力、存活率和正常形态，对生育能力的影响。
病例对照研究。
一家三级综合医院的妇产科。
从一家不孕不育诊所招募了640对连续尝试受孕夫妇的男性伴侣。其中，病例组包括218名不明原因不育的男性。招募了240名在研究时其妻子已怀孕的男性作为对照组。
所有病例组的精液参数（如密度、精子总数、活力、存活率和正常形态）均显著低于对照组。不育风险与吸烟有关（粗比值比2.82，95%可信区间1.93 - 4.13；调整后比值比2.96；95%可信区间1.98 - 4.42）。与服务和文职人员相比，技术人员（调整后比值比2.81；95%可信区间1.51 - 4.24）以及专业人员、高级官员和管理人员不育风险也更高（调整后比值比2.36；95%可信区间1.26 - 4.40）。预测不育的显著因素是吸烟、精子密度和精子存活率。吸烟增加不育几率。精子数量增加和存活精子百分比提高降低不育几率。基于多元逻辑回归模型，不育的比值比 = (94.70)×(2.88(吸烟))×(0.29(对数密度))×(0.95(存活率))。
吸烟、精子密度和精子存活率是男性不育的重要预测因素。
