In the U.S. many women of reproductive age use some form of contraception, 23% of whom use estrogen-progesterone combined oral contraceptives. Low-dose oral contraceptives suppress ovulation and dominant follicle selection by inhibiting luteinizing hormone and follicle stimulating hormone secretion by the pituitary gland. Under social, cultural and religious influences, women have traditionally been prescribed oral contraceptives in a pattern of 21 days of active pills with seven days of inactive pills as a way of mimicking the natural menstrual cycle and provide reassurance of the absence of pregnancy by a withdrawal bleed during the placebo period. However, the withdrawal bleeding that occurs during the placebo period may still present with debilitating menstrual symptoms such as cramping, spotting break through bleeding, menstrual migraines and anemia. These menstrual disorders remain one of the most common reasons for prescribing the oral contraceptives. Suppression of bleeding by discarding the seven placebo tablets has been advocated for women with severe mental disabilities that impair hygiene and proper use, as well as for occasional use by women inconvenienced by menstruation (i.e. female athletes during competition and women in the military). Additionally, many physicians have used oral contraceptive pill regimens to treat endometriosis, premenstrual syndrome, anovulatory dysfunctional uterine bleeding, acne, hirsutism and anemia. The seven day pills free ovarian axis and ovarian follicular development and increase ovarian sex steroid production which may result in mild exacerbations of the treated condition. There is a growing patient preference to avoid vaginal bleeding completely, both in pre-menopausal and post-menopausal hormone replacement regimens in the general population. This is reflected in a woman's attitude about changing menstrual bleeding patterns as assessed by a 1996 Dutch survey. The majority of women in all studied age groups said that they would prefer decreasing the frequency of bleeding to less than once a month or completely eliminating menses altogether through the use of oral contraceptives. Therefore, reducing bleeding days is an important goal for improving quality of life in women suffering from the discomfort and inconvenience of withdrawal bleeding.