What is the principle of the IUD?

The principle of the IUD is that when the embryo wants to implant in the uterus, it constantly scrapes the uterine wall, causing sterile inflammation of the uterus, making it impossible for the embryo to enter the uterus normally to implant and conceive, which will cause miscarriage and achieve the effect of contraception. In our country, many women choose IUDs for contraception.

1. The copper ions in the copper intrauterine contraceptive ring aggravate the aseptic inflammatory response of the endometrium and interfere with the activity of the enzyme system necessary for implantation, which is not conducive to the implantation of the fertilized egg and the development of the blastocyst.

2. Copper ions may also change the biochemical properties of cervical mucus, affect sperm activity and capacitation, and thus further enhance the contraceptive effect. Copper ions can also directly kill sperm and fertilized eggs.

3. The role of prostaglandins: Long-term stimulation of the IUD causes the endometrium to produce prostaglandins. On the one hand, prostaglandins can enhance uterine contraction and fallopian tube peristalsis, causing fertilized eggs that are not sufficiently developed and divided to be sent to the uterine cavity prematurely, thus affecting implantation.

4. A large amount of prostaglandins can enhance the effect of estrogen, inhibiting the decidual reaction of the endometrium during pregnancy, which is not conducive to the implantation of the fertilized egg.

5. The ring can interfere with the normal cyclic changes of the endometrium, which is not conducive to implantation; it can also affect the transport or capacitation of sperm. Intrauterine devices containing high doses of levonorgestrel may also inhibit ovulation, change the properties of cervical mucus, and hinder sperm penetration.

The mechanism of human pregnancy is that the female ovary releases an egg, the egg is fertilized in the ampulla of the fallopian tube, and then develops into an embryo (morula) in the fallopian tube. The embryo is then released into the uterus to implant and grow. Contraception is about blocking any of these steps.

The contraceptive principle of the intrauterine device (IUD) is: when an embryo wants to implant in the uterus, the constantly moving IUD scrapes the uterine wall, causing aseptic inflammation of the uterus, making it impossible for the embryo to implant and conceive normally in the uterus, thereby causing miscarriage to achieve the purpose of contraception. The essence of an intrauterine contraceptive device (IUD) is a long-term, mild abortion procedure using curettage and abortion, and it is the first choice for Chinese women to use for contraception after marriage.