How to assess the quality of the type of contraception?
To assess the effectiveness of the method of contraception, the Pearl index is used,
Despite the wide spread of the index valuesPearl in various sources (which is largely due to what factors are taken into account in the study), this indicator is a good guideline when choosing a contraceptive method. Without contraception, with unprotected intercourse, the Pearl index is 80–85. See also Antigestagens and Progestogens for Emergency Contraception
Commonly used types of contraception
- Biological methods of contraception
The woman determines the most favorable forperiod and abstains from having sex on these so-called dangerous days or uses other methods of contraception on fertile days, for example, a condom.
Other natural methods of contraception include coitus withdrawal.
- Barrier methods
At the moment, a condom and a femid (femalecondom) are the only contraceptives that protect against sexually transmitted diseases, including HIV infection, so they can also be used in addition to other (hormonal, chemical) contraceptive methods ("safe sex").
At the same time, along with protection against infections, the contraceptive effect increases.
- Hormonal contraception
Hormonal drugs act in different ways, independing on their composition. Combined oral contraceptives (COCs) suppress ovulation (that is, prevent the maturation and release of the egg), in addition, they thicken cervical mucus, thereby making the cervix impassable for sperm, and also change the lining of the uterus, so that a fertilized egg cannot attach to it ...
The principle of the mini-pili (tablets containingonly small amounts of progestin) other - they do not suppress ovulation, but only act on cervical mucus and prevent the fertilized egg from fixing in the uterus.
In 2019, American scientists developedplaster with microneedles. When the patch is applied, the needles of absorbable plastic break off and remain under the skin, after which the levonorgestrel is slowly released.
It should be noted that hormonal contraceptives have a number of significant disadvantages:
- they do not protect against sexually transmitted diseases;
- taking birth control pills should be long and constant, which requires great care and expense;
- every missed pill increases the risk of pregnancy;
- in some cases, side effects may appear - such as nausea, dizziness, vomiting, headaches, engorgement of the mammary glands, weight gain.
- Chemical methods
The effect of chemicals iscreating a barrier to sperm (changing cervical mucus or creating foam in the vagina). Available in the form of balls, pastes, ointments and tablets. They are applied topically just before intercourse.
They also include spermicides - substances that kill sperm outside the body of a man.
- Intrauterine devices
Intrauterine device and other devices placed directly in the uterus; mainly combine a mechanical effect with a long-term chemical action.
The latest methods of contraception
- Tiny implant
International biopharmaceutical company Merckpresented a tiny implant that is implanted into a person's forearm. It contains a year's supply of highly active antiretroviral therapy drugs.
Their use can protect a person withthe risk of contracting HIV from the virus. Pre-exposure or pre-exposure prophylaxis of HIV (PrEP) is the prophylactic use of highly active antiretroviral therapy in people who do not have HIV to reduce the risk of infection with the virus.
This category includes partners of people who have already been diagnosed with HIV, homosexuals with different partners, and men who cannot use contraception due to erection problems.
Clinical studies have shownthat the daily use of HIV-negative people with PrEP reduces the risk of infection by an average of 73%. An important feature of such prevention is the constant use of drugs, since they have only a cumulative effect.
Match head size implant with annualthe PrEP supply will gradually release the required amount of medication into the bloodstream. Clinical trials have shown that it is "reasonably well tolerated by the body" and effectively delivers the drug into the bloodstream.
Engineers at Georgia Tech has developed a painless, non-invasive microneedle contraceptive patch. It is enough to attach the device to the skin for five seconds once a month.
Scientists decided to use technology tocontraception and created a patch with microneedles made from polymers and the active substance levonorgestrel. They gradually dissolve in the blood and protect against unwanted pregnancy within a month.
In tests on rats, the researchers determined that 100 microneedles are enough to raise the level of levonorgestrel in the rodents' blood to the level required for contraceptive effect.
- Natural Cycle App
Department of Sanitary Supervision of QualityThe United States Food and Drug Administration has cleared the Natural Cycle app to market. This development monitors the temperature and the menstrual cycle of the user, determining which days a woman can get pregnant and which days she cannot.
The Natural Cycles smartphone app was released in the UK in 2016. It is used in conjunction with a regular basal thermometer to measure “ovulation”.
The app requires the woman to enter the exact body temperature daily in the morning; it needs to be measured with a highly reliable basal thermometer.
The app has already been certified by the EuropeanUnion as a development that can replace contraception. Now it is used by about 625 thousand users around the world, but the company already knows about 37 unwanted pregnancies that occurred in Sweden in January 2018.
The company itself also notes that the indicatorthe user's success depends on how well he adheres to the instructions. The Natural Cycles app also notes that "the only proven way to avoid getting pregnant is to abstain from intercourse."
- Gel injection
Years of human trials have been successful, and researchers are ready to submit the results for regulatory approval. The results show that the gel is safe, effective and easy to use.
However, this method of contraception does not attract the approval of pharmaceutical companies, who are afraid of losing the market.
According to experts, the release of the gel,neutralizing the activity of sperm, will take half of the market for female contraceptives - it is estimated at $ 10 billion. In addition, sales of conventional condoms will fall by about $ 3.2 billion a year.
One gel injection costs $ 10 and provideslong-term results are very disadvantageous for pharmaceutical giants. It is not surprising that so far only one non-profit organization from the United States has taken up the promotion of the new technology.
The technology works as follows: a polymer gel is injected into the vas deferens, which in consistency resembles molten chocolate.
The gel solidifies on the walls, forming something like a buffer, passing through which sperm lose their vital functions. The buffer from the gel destroys the flagellum and the nucleus of the sperm.
- Vasagel ointment
A drop of Vasagel ointment is injected into the vas deferens and acts as a long-term barrier that can be easily destroyed if ultrasound is applied to the gel.
Unlike hormonal drugs that causeside effects in the form of depression, inflammation of the sebaceous glands or a sharp increase in libido, Vasagel does not affect sperm production and hormone levels in the body.
Sperm continues to be produced, but the gel prevents it from passing through the seminal stream, and it is absorbed in the body.
The experiment involved 16 male rhesus monkeysand several females with whom they spent 2 years. During this time, not a single pregnancy was recorded, and side effects like inflammation remained at a minimal level.
It is important to remind that so far no methodcontraception does not provide 100% protection against unwanted pregnancy, except for absolute abstinence. However, it all depends on the correct use of this or that type of contraception or on a combination of several.
Because of the Sun, the Earth's atmosphere will lose all free oxygen
Physicists have created an analogue of a black hole and confirmed Hawking's theory. Where it leads?
Abortion and science: what will happen to the children who will give birth