Menstrual cycle and LH cause the remaining parts of the dominant follicle to transform into the corpus luteum, which produces progesterone. The increased progesterone in the adrenals starts to induce the production of estrogen. The hormones produced by the corpus luteum also suppress production of the FSH and LH that the corpus luteum needs to maintain itself. Consequently, the level of FSH and LH fall quickly over time, and the corpus luteum subsequently atrophies. Falling levels of progesterone trigger menstruation and the beginning of the next cycle. From the time of ovulation until progesterone withdrawal has caused menstruation to begin, the process
Menstrual disorder Menstrual disorder A menstrual disorder is an abnormal condition in a woman's menstrual cycle. Disorders of ovulation include oligoovulation and anovulation: "Polymenorrhea" is the medical term for cycles with intervals of 21 days or fewer. "Irregular menstruation" is where there is variation in menstrual cycle length of more than approximately eight days for a woman. The term "metrorrhagia" is often used for irregular menstruation that occurs between the expected menstrual periods. "Oligomenorrhea" is the medical term for infrequent, often light menstrual periods (intervals exceeding 35 days). "Amenorrhea" is the absence of a menstrual period in a woman of reproductive age.