The intrauterine device, or IUD contraceptive, is a small “T” shaped device made of plastic and either copper or progesterone (a hormone) that is inserted into a woman’s uterus. The IUD must be inserted by a doctor. IUDs prevent pregnancy mainly by inhibiting egg fertilization.

The copper IUD contraceptive’s arms are made of copper, which blocks the sperm from entering a woman’s fallopian tubes from the uterus. However, if sperm does get through, the IUD will still prevent pregnancy by inhibiting the fertilized egg from attaching to the uterus lining. Copper IUDs can stay in a woman for up to twelve years, making them an appealing choice for women who do not want to have to worry about birth control on a daily basis.

Progestasert IUD contraceptives are similar to copper IUDs, except instead of copper, they contain the hormone progesterone, the same hormone that is created by women’s ovaries during their periods. Progesterone induces a reaction in the woman’s cervical mucus—it thickens so that sperm cannot fertilize the egg and prevents a fertilized egg from attaching to the wall of the uterus. Progestasert IUDs can stay in a woman for up to a year.

The IUD contraceptive is a good choice for women in monogamous relationships; they do not prevent the transmission of STDs. They are extremely effective—their effectiveness rate is 98 to 99%—especially when compared to a condom’s effectiveness rate of 86%. There are fewer side effects associated with IUDs; women will not experience hormone level changes like they do when taking the Pill. One insertion can last from one to twelve years, which takes the worry off many women’s minds—women do not have to deal with birth control every day (as with the Pill) or every time they have intercourse (as with condoms or other types of birth control). Though the Dalkon Shield, a brand of IUD, created much controversy in the 70s due to its propensity to cause injury, today’s brands are completely safe.

However, IUD contraceptives are not for all women. Women at risk or who have experienced pelvic inflammatory disease are not recommended to use IUDs. Insertion may be painful, and it is normal to experience spotting and cramping as side effects. Not only should IUDs not be used as protection against STDs, but they could also increase the consequences of any bacterial infection, Chlamydia for example.

The IUD contraceptive is a highly effective choice for birth control. However, women who are considering using IUDs should talk to their doctors or gynecologists before making any decision. Previous health conditions may put certain women more at risk than others. Nevertheless, the IUD contraceptive, while not as popular in the United States, is widely used all around the world.