Clinical evaluation of the therapeutic effectiveness of ethinyl oestradiol and oestrone sulphate on prolonged bleeding in women using depot medroxyprogesterone acetate for contraception. World Health Organization, Special Programme of Research, Development and Research Training in Human Reproduction, Task Force on Long-acting Systemic Agents for Fertility Regulation.

A placebo-controlled randomized clinical trial was conducted in six centres to compare the effects of a 14 day treatment with either 50 micrograms ethinyl oestradiol daily or 2.5 mg oestrone sulphate daily, on depot medroxyprogesterone acetate (DMPA)-induced prolonged bleeding. Out of 1035 women admitted to the study, 278 requested treatment and were given ethinyl oestradiol (n = 90), oestrone sulphate (n = 91) or placebo (n = 97). Ethinyl oestradiol was successful in stopping the bleeding episode in 93% of cases, compared with oestrone sulphate and placebo which had success rates of 76 and 74% respectively. However, the relative advantage of ethinyl oestradiol was marginal, with an average reduction of 1 bleeding day and 3 spotting days compared with the other two groups. Immediately after treatment, women given ethinyl oestradiol had less bleeding but a more unpredictable pattern than the other two groups. In the long term, there were no differences between the bleeding patterns or the discontinuation rates for any reason in the three groups, and the most important single reason for discontinuation in those groups remained 'menstrual problems'. In summary, the study showed that treatment of DMPA-induced prolonged bleeding with ethinyl oestradiol had a limited short-term effect but no beneficial effect on the acceptability of DMPA as a contraceptive method. Treatment with oestrone sulphate was no different from placebo.