Information on advances in sciences and technology. Advances in contraceptive technology

Hormonal contraceptives include oral pills with lower steroid concentrations such as the triphasic gestodene. A dose of less than 20 mcg of ethinyl estradiol in the combined pill is effective. The use of RU-486 or mifepristone to inhibit ovulation or as a postcoital method is still being investigated. The vaginal rings that release 20 mcg of levonorgestrel (LNG) have a 97% rate of efficacy. There are newer types that release 30 mcg of LNG or desogestrel. A progesterone-releasing ring used during lactation is being studied. Among implants Norplant has been approved in many countries including by the US Food and Drug Administration with excellent results. In Brazil it continues to be banned. Studies have been initiated about implants such as Norplant 11 and UNIPLANT. The studies conducted by the World Health Organization on injectables such as Cyclofem (which contains 5 mg of estradiol cypionate and 25 mg of medroxyprogesterone acetate) as well as Mesigyna (5 mg of estradiol valerate and 50 mg of norethindrone enanthate) are awaited. These two monthly injectables have minor side effects produce regular cycles and are highly effective. The use of GnRH analogues for ovulation inhibition are held back because of cost dosage and routes of administration The hormonal IUD releasing 20 mcg of LNG holds promise for high efficacy probable protection against inflammations and pronounced reduction of menstrual bleeding particularly in long-term use. The frameless IUD called Flexigard consists of 6 fixed copper cylinders placed in the myometrium which causes less endometrial irritation and less incidence of inflammation pain and bleeding. It has been in an experimental testing phase for some years. The female condom helps prevent STDs and is under the womans control. Among male contraceptives a hormonal method awaits development while gossypol with the ability to inhibit HIV proliferation and the Chinese method of scalpel-free vasectomy are effective methods.