An incremental-dose combined oestrogen-progestogen oral contraceptive: cycle control and endometrial changes.

A study of bleeding patterns and endometrial histology was made in women using an incremental-dose combined oestrogen-progestogen formulation. The proliferative activity during the first 11 days of treatment was less well-developed, and there was an early appearance of secretory changes (transitional pattern). The increased dose of d-norgestrel resulted in an endometrium showing either early or deficient secretory changes. Menstrual patterns were very satisfactory in terms of cycle length and duration of bleeding.