Final answer:
The estrogen in oral contraceptives prevents ovulation by suppressing FSH and LH through a negative feedback loop. While pills containing estrogen can reduce certain cancer risks, they can also lead to weight gain and increased blood clot risks. It is important to use them as directed and discuss individual health considerations with a healthcare provider.
Step-by-step explanation:
The estrogen component of oral contraceptives plays a critical role in preventing pregnancy. Estrogen, typically provided in the form of synthetic estrogens like ethynyl estradiol, works in conjunction with progestins to mimic the hormonal activity during pregnancy, which prevents ovulation. The constant presence of these hormones uses a negative feedback mechanism that suppresses the production of Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH) by the hypothalamus and pituitary gland. Without FSH, follicles do not mature, and without LH, ovulation does not occur, thereby preventing pregnancy.
Apart from contraceptive benefits, birth control pills that include estrogen can reduce the risk of ovarian and endometrial cancers. However, use of estrogen in hormone therapy is associated with risks, such as weight gain and an increased chance of forming blood clots. Therefore, it is essential for those considering oral contraceptives to be aware of these potential side effects and to have discussions with healthcare providers to understand individual risks and benefits.
It is also important to note that the effectiveness of birth control pills can be compromised if not taken consistently at the same time each day, with perfect use showing a failure rate of about 1 percent, which rises to about 10 percent with typical use. Progesterone-only pills can lead to irregular menstrual periods and do not increase blood clot risks, whereas pills containing estrogen might carry this risk. For various reasons including menopause symptoms or preparation for sex-change operations, hormone therapy might be considered but should be closely monitored due to possible health risks.