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
Fern test When high levels of estrogen are present, just before ovulation, the cervical mucus forms fern-like patterns due to crystallization of sodium chloride on mucus fibers. This pattern is known as arborization or 'ferning'. When progesterone is the dominant hormone, as it would be in the second half of a normal cycle, the fern pattern is no longer discernible, and the pattern is completely absent by the 22nd day of a woman's cycle. The disappearance of the fern pattern after the 22nd day suggests ovulation, and its persistence throughout the menstrual cycle suggests an-ovulation (infertility). Fern test Fern test refers to