The monthly injectable contraceptive: A two year clinical trial

Abstract

A contraceptive regimen of monthly intramuscular injections of a combination of 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate (Cyclo-Provera, Upjohn Co, Kalamazoo, MI, USA) was studied in 111 Thai women through 2356 cycles. During the first two years of treatment, more than 80% of the patients had only one bleeding episode per cycle. The incidence of amenorrhea ranged from 3.6% to 14.9%. Average cycle length and duration of bleeding were similar to the pretreatment values. High continuation rates (79% at 12 months) indicated good patient acceptance of the method. There were no contraceptive failures or serious side effects. Return of fertility was relatively prompt. Among 21 patients who had discontinued treatment in order to plan pregnancy, 10 were pregnant within six months, and 3 others conceived during the succeeding three months. In five volunteers, serum medroxyprogesterone acetate levels were below 5 ng/ml (with one exception) after a single injection of Cyclo-Provera given at intervals up to 56 days.