Skip to main content

How do Oral Contraceptives Prevent Pregnancy? Their Mechanism of Action

mechanism of action of contraceptives
Oral contraceptives prevent conception/pregnancy due to their following effects on a woman’s body.
1. Oral contraceptive pills contain Estrogen and a Progestogen. The most commonly used Estrogen in oral contraceptive pills is  Ethinyl Estradiol while the commonly use Progestogens are Norethindrone, Levonorgestrel, Desogestrel and Norgestimate. You can see their names written in the leaflet that is supplied along with the pill pack. 
2. Oral contraceptives inhibit ovulation. they inhibit the release of the egg from the ovaries and without the egg, the male sperm can’t produce a baby. Oral contraceptives inhibit ovulation by manipulating the normal hormonal responses and blood level of a female. Hypothalamus secretes a hormone called Gonadotropin-releasing hormone (GnRH). This acts on the anterior pituitary and causes the release of FSH and LH. FSH reaches the ovaries via blood where it causes follicle maturation and development. It also signals the release of Estrogen from the follicle. Estrogen starts increasing however this increase does not occur all of a sudden rather Estrogen increases steadily. A gradual increase in the Estrogen for about 70 hours signals the LH surge. In LH surge, you have a sudden increase in the LH level and this LH surge is what will bring about the subsequent ovulation. Keep in mind that this gradual increase in the estrogen is very important for the LH surge and ovulation to occur and this is what is interfered by combined oral contraceptive pills.
Basically, oral contraceptive pills will keep the levels of Estrogen constantly elevated. When Estrogen levels remain constantly elevated there will be no LH surge. If LH surge doesn’t occur there will be no ovulation and there will be no eggs and no pregnancy will occur. This is how contraceptives prevent a pregnancy to occur.
3. They make the cervical mucus thick so that sperms cannot go up to the uterus and tubes easily.
4. These pills also make the uterine wall unfavourable for the attachment of embryo.





Comments

Popular posts from this blog

Human Parasites, Types of Parasites, and Classification

Parasite: A parasite is a living organism which gets nutrition and protection from another organism where it lives. Parasites enter into the human body through mouth, skin and genitalia. In this article, we will generally discuss the types and classification of parasites. It is important from an academic point of view. Those parasites are harmful, which derives their nutrition and other benefits from the host and host get nothing in return but suffers from some injury. Types of Parasites Ecto-parasite: An ectoparasite lives outside on the surface of the body of the host. Endo-parasite: An endo-parasite lives inside the body of the host, it lives in the blood, tissues, body cavities, digestive tract or other organs. Temporary parasite: A temporary parasite visits its host for a short period of time. Permanent parasite: Permanent parasite lives its whole life in the host. Facultative parasite: A facultative parasite can live both independently and dependently. It lives in the

How to taper off, wean off beta blocker, atenolol, Propranolol, Metoprolol

Beta blockers include, atenolol (Tenormin), propranolol (Inderal ) and metoprolol (Lopressor) and are used to treat high blood pressure, certain cardiac problems, migraine and few other conditions. People usually take atenolol, propranolol or metoprolol for many years as a treatment of high blood pressure or after having an episode of heart attack . Sometimes, it becomes necessary to withdraw these beta blockers due to their potential side effects that trouble the patients or sometimes doctor wants to change the drug and shift the patient to some other anti-hypertensive medicine. No matter whatever the cause is, whenever, a patient who has been using a beta blocker for a long period of time, and he needs to be stopped from further usage of that beta blocker, must not stop taking it. One should taper off the dose of a beta blocker. Now a question arises how to wean off or taper off a beta blocker? The method of tapering off beta blocker varies from individual to individual. Allow you