One of the most popular methods of contraception is considered oral contraceptive pills. They can be divided into three main categories: progestin - only pills, combined oral pills, and emergency contraceptive pills. The principle of oral contraceptives is hormonal substitution. The pills contain synthetic forms of human hormones: estrogens and progesterone.
The mechanism of their action is the following. At the start of each menstrual cycle the level of estrogens is low and begins to increase. When estrogen hits the highest point, usually at the 14-15th day of cycle, ovulation takes place. Ovulation is the release of an egg from the ovary. In the second part of a cycle the level of progesterone rises in order to prepare the uterus for the implantation of the eventually fertilized egg.
The preparation includes the thickening of the uterus lining. If the ovary is not fertilized by a spermatozoid, the level of both hormones decreases and the menstruation begins - the lining of the uterus is flaked off. The principle of combined oral pills is based on the maintaining of a constant low level of hormones so that the ovulation does not occur and no egg is released.
Another mechanism is that combined oral pills are thickening the cervical mucus and the spermatozoid cannot penetrate through it. Combined oral pills contain both estrogen and progesterone hormones. They are most popular of all the oral contraceptives. Combined oral pills are divided into two groups: monophasic pills and multiphasic pills.
Monophasic pills contain the same amount of both estrogen and progesterone for the entire period. They can be in packs of 21 pills and in packs of 28 pills. In those with 28 pills the last 7 pills are placebo with no hormones and with no effect on the organism. They are designed this way in order to keep the regular administration. Some of the patients may have different side-effects such as nausea, amenorrhea, spotting and some more.
That may happen because of intolerable amount of hormones. For these cases have been created multiphasic pills, which can be biphasic and triphasic. They contain different amounts of hormones so the pills must be taken at specific times and in specific order, indicated on the package. They contain lower levels of hormones and are considered to reduce the side-effects that may occur in monophasic pills use.
Combined oral pills have some important advantages. They reduce the risk for certain cancers, such as ovarian or endometrial cancer. Also they decrease the menstrual pain, cramps and blooding. Oral contraceptives may improve acne and can be prescribed in hormonal disorders, such as amenorrhea, ovarian polycystic syndrome, hirsutism (excessive hair on the face) and so on. Combined oral pills are also regulating the menstrual cycle. They have benefic effect in patients with benign breast disease and breast cysts.
The disadvantages generally refer to patients with certain medical conditions. For example, combined oral pills are increasing the risk of thrombosis and stroke, especially in smokers over 35 years. Another risk of oral contraceptives is hypertension. That is why it is important to consult a doctor before taking the pills. This way many serious consequences can be avoided.