IUDs or intrauterine devices are a type of birth control method with a high rate of success in preventing unwanted pregnancies. There are two types present on the market, the standard IUDS are T-shaped devices covered with coiled copper that are inserted directly into the uterus. The insertion process means dilating the cervix, in a doctor’s office, so that the device can be fitted into the uterus. It can be an uncomfortable procedure, producing heavier periods thereafter, and runs some risk of pelvic inflammatory disease and of infection. This risk is minimal, and most women tolerate IUDs very well. They are very popular forms of birth control in European countries and in China.
The second type of IUD is sometimes called an intrauterine system or IUS. The blockage mechanism is approximately the same but the device also releases a steady flow of progestin, which helps to chemically lower chances of pregnancy. It tends to reduce frequency, length, and heaviness of periods, in contrast to standard or inert IUDs. It does have greater side effect factors and warnings that apply to taking any type of hormonal birth control equally apply to IUDs of this type.
With the first type of IUD, after insertion into the uterus, the presence of the copper around the IUD frame acts as a natural spermicide. Additionally, IUDs cause the uterus to produce white blood cells (leukocytes), and prostaglandins within the uterus. These make the uterine environment hostile to sperm and eggs, greatly reducing potential pregnancy.
Over the lifetime of the inert IUD, usually five to ten years, total risk for becoming pregnant is approximately 4%, though for most, there is only a 1% chance of becoming pregnant.
There is a chance that the uterus can expel the IUD, particularly in the first year after insertion, and especially by women who have never had children. Normally, when IUDs stay in place, a physician must remove them, and no one should attempt to remove an IUD on their own. There are two strings that hang from the IUD, which some men do feel during intercourse. If these become problematic, they can be trimmed.
IUDs that release hormones are plastic, and have an interior cylinder that releases hormones at a controlled level. These work for approximately five years, at about a 99% effectiveness rate, but can be removed anytime. Hormonal birth control methods tend to reduce or eliminate ovulation. Progestin increases uterine mucus, which lowers speed of sperm and makes it very difficult for sperm to reach an egg if and when ovulation does occur. In the event of fertilization of an egg, progestin tends to prevent implantation, meaning a woman would naturally miscarry a fertilized egg.
It’s important to remember that an IUD is not considered a barrier birth control method, though it does provide a barrier of sorts. They will not protect against sexually transmitted diseases (STDs), and some studies suggest that the IUDs may heighten risk for contraction of HIV. It’s therefore extremely important to continue use of barrier contraception like male or female condoms to not only prevent pregnancy but also to prevent contraction of STDs.