Editor’s note: The majority of women have welcomed the intrauterine device or system, with its good reputation and reliable contraceptive effect, since its inception. Many people still affectionately call it the “ring”. But a lot of women may not know much about this “ring” that is left in the body for many years, or which type is really suitable for them.
We want to talk about the development of the intrauterine device or system, as well as the pros and cons of the various types of IUD.
Sixties and seventies: Inert IUD was the mainstream
Why does the IUD have a contraceptive effect? Generations of experts and scholars have conducted a large number of animal experiments and clinical observations, but cannot fully elucidate its mechanism of action. At present, the more unified view is that its main mechanism of action is local. The IUD is a foreign object that has an impact on the environment within the uterus, so the endometrium has a mild, chronic, non-bacterial, inflammatory response. This prompts an increase in white blood cells, which affects implantation of the fertilized egg in the uterine, embryo survival, etc., thus achieving the purpose of contraception.
It is understood that, as early as the 1950s, the IUD had landed in China and became one of the means of contraception for women of childbearing age. But very few people used this method until China began the implementation of family planning, at which time it was really openly promoted. The earliest IUD was made of an inert material, such as stainless steel, plastic or the like. Its physical and chemical performance was stable, and it did not release any active substances. Through different eras, the shape of this type of IUD underwent many changes, from the initial metal single ring, it slowly evolved to the cannabis ring and mixed ring.
The contraceptive effect of this inert IUD was poor, and it had a high loss rate. Data shows that a stainless steel metal single ring has a very high incidence of pregnancy. Generally, the pregnancy rate was 6% in the first year, while the expulsion rate was up to 1%. In addition, the risk of ectopic pregnancy was higher. In 1993, China decided to formally eliminate the use of inert IUDs. But in fact, until today, many women in rural areas or economically underdeveloped provinces are still using this type of IUD.
Eighties and nineties: Wide use of copper IUD
As the inert IUD was gradually withdrawn from the market, its successor was the active IUD. This new generation of IUD was used as a carrier for a metal such as copper or zinc, and progesterone or anti-inflammatory pain drugs. It was inserted into the uterine cavity, where the slow release of the active substances increased the contraceptive effect and reduced side effects. In the 1970s, Shanghai began production of copper IUD and developed a lot of new styles, such as the T-IUD and V-IUD.