Recommendations for Contraceptive Use
		Vasectomy

Recommendations	Rationale
a) No, based on the weight of available evidence. Studies have not been conclusive as to a possible increased risk of prostate cancer. Although several studies found no association, two studies found a slight increase in risk. A large study also found no association between vasectomy and other health effects including cardiovascular disease.	a) Based on biological and epidemiological evidence, it is unlikely that vasectomy causes prostate cancer or any other long-term health effects such as cardiovascular disease. A recent study and two earlier studies also examined the association between vasectomy and prostate cancer. Zhu et al. used a population-based case-control design in a population where vasectomy was common. No association was found. Massey et al. and Sidney et al. both used a cohort study design. The former used a retrospective cohort of 10,590 vasectomized men while the later used a prospective cohort with a mean follow-up period of 6.8 years among 5119 vasectomized men. Neither study found an association between prostate cancer and vasectomy. Giovannucci et al. found odds ratios of 1.56 and 1.66, respectively, in two separate cohort studies. However, the biological explanation for the association has not been accepted by experts as likely. Healy B. From the National Institutes of Health: does vasectomy cause prostate cancer? Journal of the American Medical Association 1993;269:2620. Zhu K, Stanford JL, Daling JR, McKnight B, Stergachis, Brawer MK, Weiss NS. Vasectomy and prostate cancer: a case-control study in a health maintenance organization. American Journal of Epidemiology 1996;144:717-22. Massey FJ Jr., Bernstein GS, O'Fallon WM, Schuman LM, Coulson AH, Crozier R, et al. Vasectomy and health: results from a large cohort study. Journal of the American Medical Association 1984;252:1023-9. Sidney S, Quesenberry CP, Sadler MC, Guess HA, Lydick EG, Cattolica EV. Vasectomy and the risk of prostate cancer in a cohort of multiphasic health-checkup examinees: second report. Cancer Causes and Control 1991;2:113-6. Giovannucci E, Tosteson TD, Speizer FE, Ascherio A, Vessey MP, Colditz GA. A retrospective cohort study of vasectomy and prostate cancer in US men. Journal of the American Medical Association 1993; 269:878-82. Giovannucci E, Ascherio A, Rimm EB, Colditz GA, Stampfer MJ, Willett WC. A prospective cohort study of vasectomy and prostate cancer in US men. Journal of the American Medical Association 1993; 269:873-7.
b) Vasectomy does not affect normal sexual function. After a vasectomy, the man's body continues to produce male hormones which help the man to have erections, sex drive/feeling, and ejaculation. A man may even feel his sex drive is increased because he no longer worries about getting his partner pregnant.	b) Vasectomy only involves the occlusion of two small ducts, not the removal of any glands or organs. Therefore, it does not interfere with the functions of the testes- testosterone production and spermatogenesis. Dias P. The long-term effects of vasectomy on sexual behaviour. Acta Psychiatrica Scandinavia 1983;67(5):333-8.

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