Final answer:
Increased estrogen levels trigger a rise in LH and FSH, leading to ovulation around day 14 of the menstrual cycle. The LH surge causes the most mature follicle to release its egg. Birth control pills maintain constant hormone levels to prevent this process, and missing doses can lead to unintentional ovulation.
Step-by-step explanation:
Does Increased Estrogen Cause Ovulation?
Indeed, increased estrogen levels play a crucial role in the process of ovulation during the menstrual cycle. Just prior to the middle of the cycle, around day 14, elevated estrogen stimulates the rapid rise and subsequent fall of Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH), with the LH surge being particularly important in triggering ovulation. When LH levels rise, this induces the most mature ovarian follicle to rupture and release its egg, an event known as ovulation.
However, the story of estrogen's impact is intricate. While initial high levels of estrogen stimulate the release of FSH and LH, eventually this leads to negative feedback, resulting in a decrease in FSH and the degeneration (atresia) of all but one of the developing follicles.
Yet, the dominant follicle continues to produce more estrogen, which switches the feedback to positive and leads to the LH surge. This high estrogen concentration also brings other changes, including increased uterine tube contractions, a decrease in vaginal acidity to favor sperm survival, and the initiation of the endometrial lining's preparation for potential implantation.
Understanding these dynamics is also vital when considering birth control methods. Birth control pills typically provide constant levels of estrogen and progesterone, which disrupts the negative feedback mechanism and prevents the LH surge, thus avoiding ovulation. Skipping pills can disrupt this balance and may lead to an inadvertent LH and FSH rise, and subsequently, ovulation.