Contraceptive pills have been used since 1960. At present, about 75 million women around the world use contraceptives for contraception.
The main functions of contraceptives are: inhibiting ovulation, changing cervical mucus, making it difficult for sperm to penetrate, or making uterine glands reduce the production of liver sugar, making it difficult for blastocysts to survive, or changing the activity mode of uterus and fallopian tubes, and hindering the transportation of fertilized eggs.
Mechanism of action
Its mechanism of action is multi-link and multi-faceted, and it varies with the composition, preparation, dosage and usage. For example, estrogen and progesterone compound preparations mainly inhibit ovulation, low-dose progesterone mainly prevents fertilization, and high-dose progesterone mainly prevents implantation. The classification of the above application mechanisms is relative.
1, steroid hormones mainly inhibit ovulation.
The plasma concentration of estrogen and progesterone increased after oral absorption, and the secretion of hypothalamic gonadotropin-releasing hormone was inhibited by negative feedback. In addition, blood sex hormones also have a direct inhibitory effect on the anterior pituitary gland, which can reduce the secretion of gonadotropin in the anterior pituitary gland and reduce the amounts of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the blood. Because the secretion of FSH is inhibited, the growth and maturation of follicles are hindered, there are no mature follicles for ovulation, and the peak of estrogen before ovulation is also cancelled. Because the LH peak disappeared in the middle period of menstruation, the ovulation process was inhibited.
2. Steroid sex hormones that mainly hinder fertilization.
Low dose progesterone can change the physical and chemical properties of cervical mucus and hinder fertilization. Progesterone can inhibit the secretion of cervical mucus, reduce the amount of mucus but increase the viscosity and cell content, which is not conducive to sperm penetration and makes it difficult for sperm to pass through, thus achieving the effect of hindering fertilization. When progesterone is dominant, sperm capacitation is inhibited and fertilization ability is lost, thus affecting fertilization. Taking low-dose progesterone continuously throughout the menstrual cycle will hinder fertilization. Its advantages are no estrogen and few side effects, but the contraceptive effect is worse than that of estrogen and progesterone compound preparation, and the incidence of irregular bleeding is higher. It has been used less.
classify
Contraceptives are divided into short-term oral contraceptives, long-acting oral contraceptives, quick-acting oral contraceptives and emergency contraceptives. Can be taken in a targeted manner according to different contraceptive needs.
1, a drug whose main mechanism is ovulation inhibition.
There are short-acting oral contraceptives, long-acting oral contraceptives and long-acting injectable contraceptives commonly used in China.
Short-acting oral contraceptives
Generally, take 1 tablet (pill) from the fifth day of menstruation for 22 consecutive days. If you accidentally miss it, you should take 1 tablet within 24 hours. Menstruation comes 2 ~ 4 days after drug withdrawal, and then take medicine on the fifth day of menstruation for the next cycle. If you still don't menstruate for 7 days after stopping the drug, you should start taking the next cycle of drugs immediately. The contraceptive effect is satisfactory and the success rate is about 100%. It is the most widely used steroid contraceptive in the world.
Long acting oral contraceptives
It is gradually released mainly by the long-term action of ethinyl estradiol stored in adipose tissue. Take 1 tablet on the fifth day of menstrual cramps, and take 1 tablet every 28 ~ 30 days thereafter. This medicine is simple and effective. However, side effects such as early pregnancy reaction and leucorrhea are more common.
Long-acting contraceptive injection
Contraceptive needle 1 and compound megestrol acetate injection. For 1 time, 1 time was injected into deep muscle on the 5th and 2nd day of menstrual cycle, and then 1 tablet was injected every month. If amenorrhea occurs after medication, you can inject 1 needle every 28 days; If amenorrhea lasts for two months, injection should be stopped, other contraceptive methods should be used during withdrawal, and injection should be resumed after menstrual cramps. This preparation is simple and effective. The main disadvantage is that large dosage will cause menstrual disorder in some women. Some areas are exploring reducing trials.
Emergency contraceptive pill
Emergency contraception is suitable for cases such as failure to take contraceptive measures in the same room, condom breakage, slipping, failure of in vitro sperm discharge, and accidental injury of women. Taking emergency contraceptive measures within 72 hours after sharing the same room can effectively prevent unintended pregnancy and prevent women from suffering from abortion. From 65438 to 0998, Yuting (scientific name levonorgestrel tablets), the first special emergency contraceptive in China, was jointly developed by the Scientific Research Institute of the National Family Planning Commission, the Contraceptive Service Center of the National Family Planning Commission and relevant manufacturers. It only needs to take one tablet within 72 hours after contraceptive failure and unprotected sex, which can effectively prevent the occurrence of unwanted pregnancy.
According to experts, over-the-counter emergency contraceptives are generally available in pharmacies, such as Yuting and Huiting. This drug is a hormone drug. Taking it many times will lead to menstrual disorder and affect your health. Please pay attention to the following items when taking:
1. can only be used occasionally. Generally, it can only be used once a month at most, not every month.
Take one tablet within 2.72 hours and one tablet every 12 hours, a total of 2 tablets. The sooner you take the medicine, the better the effect.
If vomiting occurs within 2 hours after taking the medicine, you must take one tablet immediately.
If you have sex after taking emergency contraceptive measures, you must take contraceptive measures, otherwise there is still the possibility of pregnancy.
5. Cardiovascular patients, diabetics, breast cancer patients, lactating women within half a year after delivery and people who have been diagnosed as pregnant women are strictly prohibited from using this medicine.
2. Drugs with anti-implantation mechanism as the main mechanism.
It can change the normal periodic changes of endometrium, disturb the normal transformation of endometrium, change the histology and biochemistry of endometrium, which is characterized by thinning, poor secretion and rapid atrophy and degeneration, which destroys the synchronization between fertilized eggs and endometrium and is not conducive to implantation of pregnant eggs. Anti-implantation drug is a high-dose progestin, which is not affected by menstrual cycle and can be taken on the day of visiting relatives, so it is also called visiting relatives contraceptive. Diacetylene decarbonyl ester can be used as fetal birth control pill, which has anti-implantation effect, is not limited by menstrual cycle, and does not need to take medicine continuously, but it affects estrogen activity and has great side effects.
There are mainly the following types:
Contraceptive tablets for visiting relatives containing large doses of progesterone
It is a short-term dosage form suitable for couples living apart from each other to visit relatives, and its application is not limited by menstrual cycle. There are two commonly used preparations: ① progesterone tablets. Take 1 tablet at noon on the day of visiting relatives (or 8 ~ 10 hours before sexual intercourse), take 1 tablet at night, and take 1 tablet every night thereafter until the next day after visiting relatives. ② Norethindrone tablets. Take 1 tablet every night from the night of visiting relatives and friends. For visiting relatives for more than half a month, take 14 tablets first, and then take 1 or 2 oral contraceptives. Taking it before ovulation can still inhibit ovulation, and some women have similar early pregnancy reaction after taking it, which is generally mild. Menstruation within 1 week after drug withdrawal. Because its application is not limited by menstrual cycle, it is suitable for visiting relatives.
An after-the-fact contraceptive tablet containing two progestogens
It is a flexible and simple oral contraceptive. Just take 1 tablet in the same room temporarily. On the basis of visiting relatives' contraceptives, China has developed compound progestin quick-acting tablets, such as methyl ether anti-pregnancy pills (membranes) and chloroether contraceptives, which can be used both commonly and when visiting relatives. The combination of two progestogens has additive effect, and its mechanism is multi-link, mainly to change cervical mucus, which is not conducive to sperm penetration, and will also affect the development of endometrium and the running speed of eggs, or inhibit cleavage, and even make eggs degenerate and lose implantation ability.
merits and demerits
superiority
Taking birth control pills is a safe and effective contraceptive method, which can greatly reduce the possibility of pregnancy. Used for all normal healthy women except lactation. The first advantage of birth control pills is that the success rate is relatively high. If you insist on using them, the contraceptive rate can reach 99%. Second, it is reversible, and you can get pregnant again after stopping the drug. Third, it has a certain therapeutic effect. Fourth, it is an emergency morning-after pill, which can achieve the effect of emergency contraception.
Health effects
Regular menstrual cycle
Decreased menstrual flow
Dysmenorrhea relieved or no dysmenorrhea.
Smooth skin
Reduce the risk of breast cancer, ovarian cancer and endometrial cancer.
Reduce the chance of pelvic inflammatory disease
Less uterine cysts
Can help maintain the ability to get pregnant
Make bones stronger.
Reduce the bleeding in the physiological cycle.
Reduce iron deficiency anemia
Prevention of pregnancy
side effect
1, early pregnancy-like reaction
Early pregnancy-like reactions are common, accounting for about 50% of drug users. Most of the symptoms are first severe and then mild, and then gradually disappear, which may be related to the gradual adaptation of the body. At the beginning of taking medicine, a few people have mild early pregnancy-like reactions, such as nausea, dizziness, fatigue, loss of appetite, fatigue, vomiting and so on. It often happens 1-2 weeks after taking the medicine. The reason is related to the temporary excess of estrogen level, resulting in water and sodium retention in the body and gastrointestinal dysfunction. Generally, after taking medicine for 2 ~ 3 months, the reaction can disappear or be alleviated naturally. Taking medicine before going to bed at night can make the reaction lighter during the day. Those with severe reaction can take vitamin B6, 20 mg each time, 3 times a day. If it is still not relieved, you can consider changing birth control pills and choosing drugs with less estrogen content.
2, leucorrhea increased
Mostly caused by long-acting oral contraceptives. Therefore, the drug estrogen content is high, and too much estrogen affects the secretory cells of cervix and endometrium, making them secrete vigorously and causing leucorrhea to increase.
3, breast pain
The reason is that estrogen stimulates the breast.
4, menstrual disorders
Including: ① Decreased menstrual flow or amenorrhea. This often happens after taking short-acting contraceptives, because drugs inhibit ovulation, the amount of estrogen secreted by ovaries is small, the amount of estrogen contained in drugs is also small, the endometrium can not grow normally, and the endometrium becomes thinner, so the menstrual flow is reduced, and even menopause. Decreased menstrual flow has no effect on health. If you stop menstruating for 2 months in a row, you should stop taking the medicine and use other contraceptive measures, and most of them can return to normal on their own. Menopause often happens after taking long-acting contraceptives. At this time, progesterone drugs such as medroxyprogesterone acetate or norethindrone can be used, and progesterone can also be injected. Short-acting contraceptive No.2 can also be taken twice a night for 5 ~ 6 days. Menstruation usually occurs within one week after stopping taking medicine.
② Breakthrough bleeding. Such as bleeding during medication, mostly after missing medication. A few people will have vaginal bleeding even if they don't miss taking medicine. If it occurs in the first half of the menstrual cycle, it may be caused by estrogen deficiency. You can take ethinylestradiol 0.005 ~ 0.05438+05 mg once a day until you finish taking 22 tablets. If it happens in the second half of the menstrual cycle and is caused by progesterone deficiency, you can take short-acting contraceptives 1 or No.2 1 until you finish taking 22 tablets. If the amount of bleeding is as large as menstrual cramps, you can treat it according to menstrual cramps, stop taking drugs immediately, and start taking drugs next month on the fifth day after stopping taking drugs.
(3) The menstrual flow increases and the menstrual period is prolonged. Often occurs in people who take long-acting oral contraceptives. Hemostatic drugs can be used when bleeding is heavy, and testosterone propionate can be injected when necessary. If menstrual flow continues to increase and bleeding lasts for more than 3 months, long-acting oral contraceptives should be stopped and short-acting drugs should be used instead. When using long-acting injectable contraceptives, irregular menstruation often occurs, such as prolonged menstruation, menorrhagia, shortened cycle, irregular bleeding or amenorrhea, which is more common in the first 3 months of medication. If you can persist in using it, it will gradually return to normal in the future. If bleeding occurs, ethinylestradiol can be added for 3 days.
5. Increase in weight
It may be that estrogen causes water and sodium retention, and progesterone affects anabolism (the increase of progesterone will promote protein assimilation), so some women gain weight. Generally, there is no need for treatment, and diuretics can be taken orally or given a low-salt diet, and drugs can be stopped if necessary.
6, pigmentation
After taking medicine, a few people have pigmentation on their forehead and facial skin, which is the result of estrogen and progesterone. Generally, it will recover naturally after stopping taking drugs.
Ten kinds of women who are forbidden to take birth control pills
Generally speaking, all healthy married women of childbearing age can use contraceptives, but women in the following situations should not use oral contraceptives:
1, women with acute or chronic hepatitis and nephritis should not take it. Because the contraceptives that enter the body are metabolized in the liver and excreted by the kidneys, if used by women with acute and chronic hepatitis and nephritis, it will increase the burden on the liver and kidney.
2. People with heart disease or poor heart function can't use it. Estrogen in birth control pills can make water, sodium and other substances in the body stay, which will increase the burden on the heart.
3. Women with hypertension should not use it. A few women's blood pressure will rise after taking medicine.
4. People with diabetes and family history of diabetes should not use it. Because taking birth control pills may slightly increase blood sugar and turn recessive diabetes into dominant diabetes, which will have adverse effects on female diabetic patients.
5, women with hyperthyroidism, it is best not to use contraceptives before they are cured.
6. Patients with breast benign tumors, uterine fibroids and various malignant tumors should not use them to avoid adverse effects on tumors.
7, the past or present suffering from vascular embolism diseases (such as cerebral thrombosis, myocardial infarction, vasculitis, etc.). ) can't be used. Estrogen in birth control pills may increase blood coagulation and aggravate cardiovascular disease.
8. Women with chronic headache, especially migraine and vascular headache, should not use it, otherwise it will aggravate the symptoms.
9. In the past, it was best not to have too little menstruation. Long-term use of contraceptives will shrink the endometrium and reduce menstrual flow.
10, not suitable for lactating women. Contraceptive pills can reduce milk secretion and quality, and can also enter milk, which has adverse effects on lactating children and is not suitable for lactating women.
Attention problem
1, you must form a good habit of taking all kinds of contraceptives accurately, on time and in quantity, and the taking time cannot be changed or extended at will. Don't miss it or be late. If it is found missing, take it the next day, otherwise it will easily lead to irregular bleeding or contraceptive failure.
2. Contraceptive pills should be properly kept to prevent children from taking them by mistake. If the tablets are wet, melted or the sugar coating is worn or crushed, do not take them, so as not to affect the contraceptive effect or cause vaginal bleeding.
3. Long-term contraception should be taken under the guidance of a doctor. The duration of short-acting drugs is usually 6-7 years, and long-acting drugs are 3-4 years. Explore new contraceptive methods no more than twice a year. Can be used alternately with other contraceptive measures.
4. People with acute or chronic hepatitis, nephritis, tumor, diabetes, thrombotic diseases, heart disease and severe hypertension should not take it.
5. Women who are breastfeeding or over 45 years old should not take it within half a year after delivery.
6. Pregnancy should be terminated during medication. It is required to stop taking drugs for half a year before pregnancy to prevent birth malformation.
oral contraceptive
Oral contraceptives have been available for more than 40 years this year. As a long-term medication for healthy young women, it is one of the most widely, thoroughly and safely studied drugs for human beings. For most women, this is a very reliable reversible contraceptive method. As long as it is taken correctly, its reliability can reach above 99%, which is comparable to sterilization.
At present, more than 65438+ billion women in the world are taking oral contraceptives, and most of the users in developed countries are 18-30 years old. Oral contraceptives are one of the most widely used contraceptive methods in western developed countries, with a utilization rate as high as 30%-50%. Among German women aged 20-49, 88.9% have used oral contraceptives on average. In Sweden, 90% of women have used oral contraceptives in their lifetime, and one third of women aged 15-44 are taking oral contraceptives. The utilization rate of oral contraceptives in China is less than 3%.
For most healthy women, the advantages of oral contraceptives far outweigh the disadvantages. However, this does not mean that it is suitable for every woman. Before choosing contraceptives, you should make sure that you have no contraindications to oral contraceptives, such as pregnancy, unexplained vaginal bleeding, liver disease, thrombosis or history of thrombosis, hormone-dependent tumors, etc. Women with symptoms such as cardiovascular disease are also not suitable for taking oral contraceptives.
Oral contraceptives are the most reliable for long-term use, at least for several months or years. Even if you may not have sex for a while, you'd better continue to use Marvelon. Because your body needs time to get used to oral contraceptives. And if you insist on taking it and establish your own medication rules, the risk of unintended pregnancy is very, very low.
It's very important not to lend your birth control pills to others, including your friends. Because different brands of contraceptives contain different ingredients. If you suddenly start taking an unused brand, you may feel a little uncomfortable because your body needs to adjust itself to another new hormone level.
If you need surgery or stay in bed for a long time, you need to stop taking oral contraceptives one month before surgery (major surgery or rest). Some operations may increase the risk of thrombosis if they need to lie still for a long time.
Most people will have no problem taking birth control pills, but a few people may have some side effects because of their physical relationship. However, it doesn't matter, they will be safe with a little treatment.
Early pregnancy-like reactions, such as nausea, vomiting, picky eaters, etc. After taking oral contraceptives, it is a temporary phenomenon that estrogen in contraceptives stimulates the gastric mucosa. When the gastric mucosa adapts to this stimulus, it will become a habit. People with strong reaction need to take some drugs to control this reaction, such as vitamin B6 and anisodamine, or eat some foods rich in vitamin B6, such as lean meat, liver and egg yolk, which can shorten this uncomfortable process.
Menstrual disorders After taking contraceptives (especially short-acting contraceptives), individual people may have menstrual disorders, and those who are mild do not need treatment. Generally, those who have been menopausal for more than two months should switch to other contraceptive measures. At the same time, they should take 50 mg of chlorpheniramine every day for 5 days, then take it for 5 days in the next month, and then take it for 3 months to get better.
After missing the contraceptive pill for some reason, uterine bleeding may occur. If it happens in the first half of menstrual cycle, you can take ethinylestradiol 0.05 ~ 0. 15 mg until you finish taking 22 tablets; If it happens in the second half of the menstrual cycle, you can take 0.5 ~ 1 capsule every night until you finish taking 22 capsules. It is best to eat some iron-rich foods such as animal liver and blood.
Some women with pregnancy spots will have pregnancy spots after taking birth control pills. In fact, this stain is not unique to pregnancy, and it will also appear when the growth rate of estrogen and progesterone levels in the body is high. For this stain, as long as the contraceptive is stopped, it will gradually fade away. If you can add some fresh vegetables and fruits rich in vitamin C to your diet, such as vegetables, Chinese cabbage, celery, tomatoes, oranges, oranges and so on. The stain will disappear faster.
external contraceptives
Most of them have strong spermicidal effect and are generally made into gels, tablets or suppositories. And put it into the vagina to play a spermicidal role. Such as mercuric phenylacetate, mercuric phenylnitrate, phenyl alcohol ether, etc. The contraceptive effect is not ideal when used alone, but it can be improved when used at the same time.
Before using vaginal contraceptives, you should clean the vulva, then wash your hands, and use your index finger to penetrate the membrane into the vagina until you reach the posterior fornix. 10 minutes later, the drug film is completely dissolved and sexual intercourse can be achieved. If there is no sexual intercourse within 30 minutes after placing the medicated membrane, 1 medicated membrane should be placed again to improve the contraceptive effect. If you have sex again after an interval of 1 hour, you should put 1 piece of spermicide again, otherwise it is easy to get pregnant.
If you find that the film is hard (which is easy to happen in cold weather), you can reuse it by heating it with your palm a little. Generally, the film can be preserved for two years under moisture-proof conditions, and can be used as long as it does not expire.
A few women are allergic to external contraceptive membranes. If there are some adverse reactions such as pruritus, burning, redness and swelling of vulva, stop using it.
Contraceptive drugs
Animal experiments have proved that gossypol acetate, a male contraceptive, can destroy sperm, sperm cells and spermatocytes in seminiferous tubules of testis, inhibit spermatogenesis and make semen lack of sperm. After short-term administration and drug withdrawal, the fertility of animals can be restored. The clinical trial results show that the effective rate of this product is over 99%. However, about 1% of drug addicts have hypokalemic myasthenia during taking the drug, so it cannot be popularized.
Misunderstanding of contraceptives
Myth 1: Make you fat.
Studies have shown that women are equally likely to gain weight and lose weight during medication. Even signs of obesity usually only appear in the first month after taking the medicine, that is, when the body adapts to the medicine. If you are still fat after a month, you may need to change a contraceptive, which is a hormonal medicine.
Myth 2: If you don't stop taking medicine for a week, it will be harmful to your health.
Strange to say, but this abstinence week is really dispensable. Early birth control pills were designed to imitate the menstrual cycle, because manufacturers thought that female friends still wanted a 28-day cycle during taking the pills. In other words, you can take the medicine with confidence, and there will be no "massive bleeding" once a month, but remember to go to the general practitioner for examination frequently.
Myth 3: Contraceptive pills have many side effects, such as nausea and headache.
Some birth control pills have side effects (but, you know, three-point poison), but most women don't have such a reaction. If you feel uneasy about this, please see a doctor and try to change a hormone medicine.
Myth 4: Taking a double dose will double the effect.
Doubling your medicine won't give you double protection. However, if you forget to take medicine (47% of women do), you can make it up within 12 hours. Over 12 hours, checked by GP. If the drug is used properly, the effective rate is 99%.
How to choose birth control pills
(1) If the husband and wife are together and live a regular life, they can take short-acting oral contraceptives, such as 1 and No.2 oral contraceptives; Take one tablet every day from the fifth day of menstruation for 22 days.
(2) When the husband and wife are together, their lives are irregular and they can't insist on taking it orally every day. You can choose a long-acting oral contraceptive, such as compound 18 norethindrone, once on the fifth day of menstruation, twice every 20 days, and once a month thereafter, one tablet at a time.
(3) The husband and wife are separated. You can take birth control pills when visiting relatives, such as visiting relatives tablets 1. Take one tablet 8 hours before sexual intercourse, then take 1 tablet every night until the end of visiting relatives and take it again the next morning. Not suitable for long-term use.
(4) If other contraceptive methods are found to be ineffective, or the victim is raped, the morning-after contraceptive, such as diethylstilbestrol 50 mg, can be taken within 24 hours for 5 consecutive days.
(5) Women who suffer from gastrointestinal discomfort caused by oral contraceptives can choose contraceptive needles.