A new WHO study shows hormonal male contraception prevents pregnancy.

2003 DEC 4 - (NewsRx.com & NewsRx.net) -- A new WHO study shows hormonal male contraception prevents pregnancy.

"WHO studies provided proof of concept for hormonal male contraception using a prototype androgen-alone regimen. Combined testosterone plus progestin regimens offer more practical promise, but no contraceptive efficacy studies have been completed. The objective of this study was to establish the proof of principle for depot hormonal androgen/progestin combination as a male contraceptive," investigators in Australia report.

"We performed a contraceptive efficacy study of 55 healthy men in stable fertile relationships seeking a change in contraceptive method. Testosterone (4 200-mg implants, every 4 or 6 months) and 300 mg depot medroxyprogesterone acetate, intramuscularly (im), every 3 months were administered. Once sperm output was suppressed (

"The main outcome measure was contraceptive failure (pregnancy) rate. No pregnancies occurred in 426 person-months (35.5 person-years; 95% confidence limits for contraceptive failure rate, 0-8%/annum), superior to the first year failure rate of condoms, the only reversible male method. Sperm density fell rapidly, so 94% of men entered the efficacy phase by 3 months, with only 2 of 55 (3.6%) men not sufficiently suppressed to enter efficacy."

"A few men treated with testosterone implants at 6-month intervals demonstrated androgen deficiency symptoms and/or escape of gonadotropin and spermatogenic suppression between months 5 and 6; after a protocol amendment, all men receiving testosterone implants at 4-month intervals avoided androgen deficiency or loss of gonadotropin and sperm output suppression. Recovery was complete (median, 3.6 months to sperm reappearance and 5.0 months ...