Between 1988 and 1992, a randomized phase III clinical trial was conducted in China to compare three monthly injectable contraceptives: Mesigyna, Cyclofem and Injectable No. 1. This paper presents a detailed analysis of the menstrual diaries provided by 5098 (89%) of the subjects. In total, 902, 903 and 913 diaries were analyzed to compare bleeding patterns induced by Mesigyna, Cyclofem and Injectable No. 1. The first withdrawal bleeding usually occurs 14-20 days after the first injection for all three of these preparations. Thereafter, 50% of Mesigyna users had precisely 3 bleeding/spotting episodes every 90 days, 50% of Cyclofem users had 2-3 and 50% of Injectable No. 1 users had 3-4 episodes every 90 days. Relative to users of Mesigyna or Cyclofem, Injectable No. 1 users had 2-3 more bleeding/spotting days, and a shorter length of bleeding/spotting-free intervals in each period. 63.7%, 41.4% and 60.6% of subjects using Mesigyna, Cyclofem and Injectable No. 1, respectively, had bleeding patterns similar to their untreated patterns in the first 90-day period. The percentages increased to 82.2% 67.8% and 75.0% in the fourth 90-day period. A total of 1815 diaries for Mesigyna and 1802 for Cyclofem were analyzed for more in depth comparison of these two methods. The number of bleeding/spotting days over four periods showed little difference between the two group, but there were more spotting days and there was greater individual variability among Cyclofem users.(ABSTRACT TRUNCATED AT 250 WORDS)
PIP: Between October 1988 and July 1990, a randomized multicentered phase III clinical trial was conducted in three provinces of China to compare three monthly injectable contraceptives (Mesigyna [50 mg norethisterone enanthate + 5 mg estradiol valerate], Cyclofem [25 mg medroxyprogesterone acetate + 5 mg estradiol cypionate], and Injectable No.1 [250 mg 17-hydroxyprogesterone caproate + 5 mg estradiol valerate]). A detailed analysis of the menstrual diaries of 5098 women aged 18-35 years compared the vaginal bleeding patterns associated with the injectables. Women in all three groups experienced more bleeding/spotting (B/S) days, more bleeding episodes, shorter bleeding-free intervals, and larger variability during the first 90 days than during the following three 90-day periods (p 0.001). 90% of Cyclofem users had 1-4 B/S episodes. 90% of Mesigyna users had 2-4.2 B/S episodes. Cyclofem users had more spotting days than did Mesigyna users in each 90-day period (5-8 vs. 5-6). Acceptable bleeding patterns (i.e., bleeding patterns similar to untreated patterns) predominated, on the most part, in all four periods (63.7-82.2% for Mesigyna users, 41.4-67.8% for Cyclofem users, and 60.6-75% for Injectable No.1 users). Acceptability increased with each 90-day period for all three injectables. Acceptability of bleeding patterns was much higher among Mesigyna users than Cyclofem users (p 0.001). Prolonged bleeding, followed by irregular bleeding and frequent bleeding, were the most common bleeding disturbances. Irregular bleeding decreased with time. 79.1% of Mesigyna and Cyclofem users who finished the study had an acceptable pattern. 70.7% of women who stopped for non-bleeding reasons had an acceptable pattern compared to 31.3% of those who stopped for bleeding reasons. These findings show that Mesigyna users experienced better cycle control and more acceptable bleeding patterns than did the users of the other two injectables.