据估计有六分之一的夫妇怀孕困难。这些患者中单独由男方因素造成的占20%。另有30%到40%的夫妇怀孕困难是由男方因素合并其他因素如无排卵、输卵管因素、产妇高龄及子宫内膜异位症等造成的。[3]Sharlip ID, Jarow JP, Belker AM, et al. Best practice policies for male infertility. Fertil Steril. 2002;77:873-882.http://www.ncbi.nlm.nih.gov/pubmed/12009338?tool=bestpractice.com男方因素导致不育的发生率在西方国家逐渐增高。这种增高由许多因素导致,肥胖是其中之一。[4]Jensen TK, Andersson AM, Jorgensen N, et al. Body mass index in relation to semen quality and reproductive hormones among 1,558 Danish men. Fertil Steril. 2004;82:863-870.http://www.ncbi.nlm.nih.gov/pubmed/15482761?tool=bestpractice.com暴露于环境内分泌干扰物或异生物素的普遍程度和严重程度的逐渐增加越来越受到关注。[5]Storgaard L, Bonde JP, Olsen J. Male reproductive disorders in humans and prenatal indicators of estrogen exposure: a review of published epidemiological studies. Reprod Toxicol. 2006;21:4-15.http://www.ncbi.nlm.nih.gov/pubmed/16005180?tool=bestpractice.com