早在1965年就有人试用每三个月注射一次甲地孕酮醋酸酯(DMPA)来避孕。通过一系列多中心试验,证明这一方法是可行的。随后在国际协作下又进行了每六个月注射一次DMPA300毫克的避孕试验。其结果仅在妊娠率方面有所差别,三个月注射一针的妊娠率每100妇年为0.25,而六个月一针的妊娠率为1.73。后来试用每六个月注射一次450毫克DMPA的试验,其结果妊娠率为1.58,与300毫 As early as 1965, some people tried to inject megestrol acetate (DMPA) once every three months to get contraception. Through a series of multicentre experiments, this method is proved to be feasible. Subsequently, a further contraceptive test of DMPA 300 mg was given every six months with international collaboration. The results differ only in terms of pregnancy rates, with a three-month pregnancy rate of 0.25 per 100 women and a pregnancy rate of 1.73 for the six-month-old needle. Later trial of a 450 mg DMPA injection every six months, the result of pregnancy rate was 1.58, and 300 milli