What is the primary function of an intrauterine device (IUD)?

The primary function of an intrauterine device (IUD) is to prevent pregnancy. IUDs are small, T-shaped devices that are inserted into a woman's uterus by a healthcare professional. They work primarily by either preventing sperm from fertilizing an egg or by inhibiting a fertilized egg from implanting in the uterine lining.

IUDs can be hormonal or non-hormonal, with hormonal IUDs releasing progestin to thicken cervical mucus and thin the uterine lining, while non-hormonal copper IUDs create an environment that is toxic to sperm. This dual mechanism greatly reduces the likelihood of conception, making them one of the most effective forms of reversible contraception available.

While promoting uterine health, preventing sexually transmitted infections, and regulating menstrual cycles may have some association with the use of IUDs, these are not their primary functions. The central role of IUDs in family planning is to actively prevent unwanted pregnancies.