Contraception is the application of scientific methods to make a woman temporarily infertile. It is a method that controls three aspects of the reproductive process: 1) inhibits the production of sperm and eggs; 2) prevents the union of sperm and eggs; and 3) makes the uterine environment unfavorable for the sperm to be able to survive or for the fertilized egg to be laid and develop. Common contraceptive methods include: birth control pills, condoms, IUDs, contraceptive injections, safe period contraception, in vitro ejaculation and surgical contraception, etc. Choice of contraceptive methods Short-acting oral contraceptive pill (COC): the first choice for contraception after early pregnancy abortion, WHO recommends taking it immediately after abortion. It is usually taken from the first day of menstruation, one oral tablet per day, and the efficiency of the oral contraceptive pill is close to 100% when used correctly. Its contraceptive principle is to inhibit ovulation through estrogen and progesterone. In addition to its contraceptive effect, it can actually be used in the treatment of acne, menstrual irregularities, endometriosis, etc. It is still very reliable in terms of safety. Side effects include weight gain (the newer generation of oral contraceptives, eusebio, does not have this effect) and an increased risk of venous thrombosis in the lower extremities. Long-term use of oral contraceptives should also be avoided in people over the age of 40. IUD: A long-lasting and reliable method of birth control for women who have not had children for a long time. The material usually contains copper, and the principle of contraception is to influence the fertilization of the egg through the local reaction of copper. Usually, it can be left in place for 5-10 years, with the former metal ring lasting longer. In recent years, a new type of hormone-containing contraceptive ring (Manuel) has been introduced to the market, which, in addition to its contraceptive effect, is also useful for the treatment of endometriosis and dysmenorrhea. Condom: It is the most commonly used and safest method, and the only method of contraception that can prevent STDs. It is suitable for any age from adolescence to perimenopause. It can be used as a transitional measure before choosing other contraceptive methods. It is not as effective as the pill, but adherence to the correct method can improve the success rate of contraception. Contraceptive injection: The mechanism of contraception is to inhibit ovulation. It is given by injection once every 2 to 3 months and has a large side effect. Normal fertility takes time to return after stopping the contraceptive injection, usually 6 to 24 months after the last injection; may be accompanied by side effects such as irregular bleeding, prolonged periods, increased menstrual flow, and some women may experience weight gain. The monoprogestin injection may cause amenorrhea in some patients. Subcutaneous implantation: A rod releasing the drug is implanted under the skin of the arm through a small incision that can last up to 3 years and may cause amenorrhea and spotting in some patients. Spermicide: It is used topically in the vagina in gels, foams and suppositories. It is inconvenient to use and less effective in contraception. Female sterilization: This procedure is indicated for adult women who expect to be permanently sterilized and who have no contraindications to the procedure. It is not suitable for women who want only temporary or reversible contraception, and requires hospitalization for open or laparoscopic surgery, with signed consent of both spouses before the procedure. In vitro ejaculation: It is not recommended because of its poor contraceptive effect and its impact on male health and the quality of sexual life. Safety period: Because the time of ovulation varies from person to person, and sperm can survive in the body for several days, making safety period contraception a very unsafe method with relatively low contraceptive effect. Emergency contraceptive pill: It cannot be used as a regular contraceptive measure because it has a large hormonal content and side effects, and may lead to menstrual disorders after taking it, so it is only used as a remedy for unprotected sex and cannot be used repeatedly and routinely. The choice of the right contraceptive method for you should be based on your age, disease and whether you have any recent childbirth requirements. If you plan to have children in the short term after marriage, you can choose barrier contraceptive methods such as condoms or short-acting oral contraceptive pills. If you do not want to have children in the near future, you can consider IUD, subcutaneous implantation or long-acting contraceptive injection. If you are breastfeeding after childbirth, you can use condoms or IUD, and if you have excessive menstruation, dysmenorrhea, endometriosis, myometriosis, etc., Manuel or short-acting oral contraceptive pills are an ideal choice.