A four year study of vasectomy on plasma levels of pituitary and sex hormones in normal males in Sri Lanka.

PIP: Blood levels of pituitary gonadotropins, prolactin, testosterone, and estrogens were measured at regular intervals in Sri Lankan males of proven fertility for a period of 4 years after vasectomy. All assays were done by standard radioimmunoassay procedures using materials supplied by the World Health Organization, Geneva, under their Special Program of Research, Development, and Research Training in Human Reproduction (Matched Assay Reagent Program), which also provides for internal and external quality control of results. No significant alteration from basal values of any of the hormonal levels measured was observed over the 4-year period. The results may increase confidence in vasectomy as a means of contraception. The effects of vasectomy on the plasma levels of the abovementioned hormones were investigated over a 4-year period from February 1975. Blood samples were obtained prior to surgery and at regular intervals thereafter for 4 years so that each subject served as his own control. Serum was stored deep frozen and the relevant hormonal measurements made in batches by radioimmunoassay techniques with suitable precautions for both internal and external quality control.^ieng