[Male contraception by hyperthermia]

Assessment of the contraceptive efficacy of a daily mild increase (1 degree C to 2 degree C) in testicular temperature during waking hours is reported in nine couples using two techniques of immobilization of the testes in a supra-scrotal position (close to the inguinal canal). With technique 1 (3 couples and 42 cycles), immobilization was achieved with a specific underwear; there was one undesired pregnancy from a man who stopped the heating for 3 weeks. With technique 2 (6 couples and 117 cycles), immobilization was achieved by adding a supplementary ring to the specific underwear; there was no pregnancy. Reversibility and safety were evaluated. These results suggest that a daily mild increase in testis temperature could be a potential contraceptive method for men.