NEW ORAL CONTRACEPTIVE: SEQUENTIAL ESTROGEN AND PROGESTIN.

The first 1000 women-years of use of a sequential mestranol (80 mcg) and mestranol plus chlormadinone acetate (2 mg) to produce a satisfactory maturation of the endometrium and insure regular and consistent withdrawal is reported. Acceptability was high: 24 women (of 1191) discontinued medication because of side effects. 6 planned pregnancies occurred in spite of claimed reliable tablet intake; 7 other pregnancies occurred associated with omission of tablets. Posttreatment fertility was 50% in the 1st month and 70% by the 3rd cycle. Mean cycle length was 27.8 days. 83% of the women noted no change in amount of flow. Sequential therapy was highly effective in relieving functional dysmenorrhea. Endometrial biopsy showed that 5 days of chlormadinone acetate caused substantial progestational changes of the endometrium. Breakthrough bleeding occurred in 2.6% of the cycles nausea in 2.5%. There was a low incidence of weight gain.