IUDs, or intrauterine devices, are a type of birth control that is inserted into the woman's uterus. The American Pregnancy Association states that the IUD is a T-shaped plastic unit, though the makeup of the device varies.
Types
Two types of IUDs are available to women, according to the American Pregnancy Association: copper-based IUDs and progestin-based IUDs.
Mechanism
The American Pregnancy Association states that both the copper-based IUD and progestin-based IUD change the cervical mucus, which acts as a spermicide and a barrier. The IUDs may also thin the lining of the uterus, preventing implantation. Progestin-based IUDs also suppress ovulation.
Effectiveness
Planned Parenthood notes that less than one in 100 women will become pregnant while using an IUD over the course of a year.
Pregnancy Risks
If a woman becomes pregnant while an IUD is still inserted, Planned Parenthood states that she is at risk for early labor, miscarriage, ectopic pregnancy and pelvic inflammation.
Length of Insertion
Copper-based IUDs can be inserted for up to 12 years, while progestin-based IUDs can be inserted for up to five years, according to Planned Parenthood.
