Introduction
Conventional oral contraceptives (OC) contain 21 days of active pills followed by 7 hormone-free days. The 28-day cycle OC were designed to mimic natural menstruation in hopes of gaining acceptance from physicians, the general population, and the church when oral contraception was still a novel idea. It is a common misconception that the 28-day cycle is necessary. The pill-induced menses does not occur by the same mechanism as natural menstruation. A woman's menstrual cycle begins with an increase in estrogen. Estrogen causes a build-up of the endometrium lining in the uterus, preparing the woman for pregnancy. Estrogen also stimulates luteinizing hormone which, along with follicle stimulating hormone, helps prepare and trigger the release of an egg from the ovary. Progesterone is produced from the released egg and continues to thicken the endometrium lining for pregnancy. If fertilization does not occur, progesterone production diminishes.
The endometrium lining is then shed due to the decrease in progesterone. However, when a woman is taking OC, hormones are maintained at a constant level. Since there is no rise in hormones, there is little build-up of an endometrium lining. The menstruation that results with OC is simply a mechanism of hormone withdrawal and therefore not clinically needed. Based on this concept, Duramed Pharmaceuticals developed Seasonale®, an extended-cycle OC. Seasonale® contains 84 days of active pills followed by 7 hormone-free days. This differs from other "continuous-cycle" OC that modify a conventional 28-day OC by skipping the hormone-free pills and continuing with a new package of active pills. Both extended-cycle and continuous-cycle OC allow a woman to experience only four menstrual cycles per year versus the normal number, 12.
Many women are skeptical about altering their menstrual cycle without realizing that today's lifestyle already alters this cycle.......
