Natural contraception, also known as safe period contraception, is a method of determining whether a woman is in an infertile period (around ovulation) by measuring basal body temperature and monitoring changes in cervical mucus. It is a family planning measure that avoids this period and chooses to have sex at a time when conception is not likely to occur in order to achieve contraception. The advantages of natural contraception are clear: it is inexpensive and does not require the use of drugs or medical treatment. The disadvantage of natural contraception is that the effective contraceptive rate is only 75%, which means there is a 1/4 chance of “winning” the lottery. Therefore, this method is only recommended for married people who are planning to have children. Extracorporeal ejaculation is a method of contraception in which the man pulls out his penis when he is about to ejaculate and ejaculates his semen outside the woman’s body. If the man pulls out at the right time every time, the rate of unwanted pregnancy is still low, about 4% per year. However, it is more demanding for gay men, who inevitably forget the time while in the throes of passion, and if they can’t do it at the right time, the rate of unintended pregnancies can rise to 18% per year. It is important to note that women may be allergic to male semen. It can be a sensitizer due to its many different antigens. It presents as a red papule on the genitals, similar to some sexually transmitted diseases, and requires differential diagnosis. In severe cases, it can lead to infertility and recurrent miscarriages. At the same time, men can also have an allergic reaction to a woman’s leukorrhea. Summary Advantages of non-instrumental contraception: no cost, but it should be noted that this method is not effective in preventing sexually transmitted diseases, and the rate of effective contraception is generally not high. External contraception – male condom The latex male condom is the most traditional and widely used of the barrier methods. It provides contraception by preventing contact between sperm and egg, and also prevents the spread of infectious diseases. The lubricant in most male condoms on the market is methyl silicone oil. It is believed that methyl silicone oil is weakly alkaline and can remain in the female vagina after long-term use, which may upset the acid-base balance; this may lead to reproductive disorders, especially the incidence of vaginitis, which may be increased. However, there is no large sample of experimental data to support this. In terms of preventing sexually transmitted diseases, although some diseases are caused by viruses with small diameters, such as HIV, which is only 1/25 the size of a sperm. And a small hole that theoretically blocks sperm does not necessarily block HIV. However, the traditional condom remains the only barrier used to prevent the spread of STDs, including HIV, between the sexes. Studies have shown that when used correctly, traditional condoms are 95% effective in preventing HIV. Other external contraceptive methods include the female condom. When placed in the vagina before sex, they are more effective in preventing STDs. As well as cervical caps, vaginal contraceptive sponges, etc., but less used in China. Emergency Contraceptive Pill (ECP) As a preventive and remedial “morning-after pill”, the ECP is widely used. It consists of a high dose of a highly effective progestin (levonorgestrel) or a selective progesterone receptor modulator (ulipristal acetate). It should be noted that some people may confuse the emergency contraceptive pill with mifepristone, which is actually not a class, and the emergency contraceptive pill does not have the anti-early pregnancy or teratogenic effects of the former. China’s most common emergency contraceptive pill or levonorgestrel preparations, contraceptive effect with the extension of time and decreasing, that is, the earlier the drug, the better the effect. However, it should be noted that large doses of high-efficiency progestin inhibit ovulation through negative feedback inhibition of the HPO axis (ovary-pituitary-hypothalamus), and long-term application will inevitably have a certain impact on menstruation and ovarian function. Oral contraceptive pills The compound short-acting oral contraceptive pills currently available on the market are estrogen-progestogen combinations. By inhibiting ovulation, changing the cervical mucus, changing the morphology of the endometrium and the function of the fallopian tubes to play a contraceptive role. The rate of effective contraception is quite high. However, taking it every day is a big problem for some women, because once the dose is missed, the effect will be greatly weakened, and it can also cause withdrawal bleeding and other situations. As for oral contraceptives such as Momoflower, it has a certain ovarian inhibitory effect due to its high potency estrogen. For patients with already poor ovarian function, it will aggravate the inhibition of the hypothalamus-pituitary gland. It is important to note that there may be adverse effects such as spotting of the menstrual cycle and breast pain. In addition to the drug contraceptive methods, there is also the subcutaneous implant contraceptive method, a match-sized implant can be effective contraception in 3 years, can be considered “once and for all”, and the contraceptive failure rate is less than 1%, but the domestic is less common. Surgical contraception Intrauterine device (IUD) IUD is widely used in China, and the basic national policy can be said to be a great credit. It has evolved from the most common stainless steel ring, to the copper-containing IUD, to the current Mannuelle, which can treat endometriosis. Because the IUD is effective for a long time, affordable, easy to operate and does not affect pregnancy, it is the first choice for married women who do not want to have children for the time being. However, it should be noted that it may slip out of the uterus and can sometimes lead to pregnancy with the device. Tubal Ligation Tubal ligation is a contraceptive method that surgically closes the fallopian tubes so that the egg and sperm cannot combine. It is a permanent form of contraception. Tubal ligation is almost 100% effective in preventing pregnancy. Tubal ligation can be performed if it is determined that you do not want to have children. Theoretically, tubal ligation can be followed by tubal recanalization, but the effective pregnancy rate after recanalization is much lower than that before tubal ligation, so please think twice about having the procedure done. An equivalent procedure is the vasectomy: a surgical closure of the vas deferens that prevents the release of sperm, but still allows ejaculation. The rate of effective contraception is almost 100%. It is a permanent method of contraception for men. It is important to note that although it is theoretically possible to perform a vasectomy, it is more difficult to do so and the results are generally good. Of all the methods of contraception, hormonal contraception, the IUD and permanent contraception have a very high rate of effectiveness; barrier methods have a medium rate of effectiveness; and ejaculation and natural methods have the lowest rate of effectiveness.