A COMPARATIVE-STUDY ON THE RETURN TO OVULATION FOLLOWING CHRONIC USE OF ONCE-A-MONTH INJECTABLE CONTRACEPTIVES

A comparative study was undertaken involving 21 Mexican women who disc ontinued the use of medroxyprogesterone acetate 25 mg plus oestradiol cypionate 5 mg (Cyclofem) and norethisterone enanthate 50 mg plus oest radiol valerate 5 mg (Mesigyna) to assess the time required for the re turn to menses and ovulation. All subjects were exposed to once-a-mont h injectable contraceptives for two years and were followed for 120 da ys after the last injection. The urinary concentration of oestrone glu curonide and pregnanediol glucuronide was determined daily in all subj ects beginning one month after the last injection. The results disclos ed that ovulatory cycles were documented after 120 days of the last in jection in six women of each studied group. Similar endometrial bleedi ng patterns were observed in both groups, indicating that the two drug s have alike pharmacokinetic and pharmacodynamic effects.