Risk factors for female and male infertility: results of a case-control study.

In order to evaluate male and female risk factors for infertility in a case-control study, we have compared all couples in a French administrative region consulting for primary or secondary infertility (of more than one year's duration) with couples in which the woman had given birth during the year of the study. For any one couple, a history of varicocele, male genital infections or testis damage multiplies the risk of primary infertility by a factor of 28, 3 and 4 respectively, and previous female infections (salpingitis) multiply the risk by 45. Similarly, a history of ectopic pregnancy, sexually transmitted diseases or salpingitis multiplies the risk of secondary infertility by a factor of 5, 4 and 7 respectively, and a history of varicocele multiplies this risk by 4.