Final answer:
An IUD is a long-term, T-shaped contraceptive device inserted into the uterus, available as copper or hormonal types. It is highly effective with a failure rate of less than one percent. IUDs prevent sperm from reaching an egg or suppress ovulation, and fertility returns quickly upon removal.
Step-by-step explanation:
An Intrauterine Device (IUD) is a T-shaped contraceptive device inserted into the uterus. It comes in two types: the copper IUD and the hormonal IUD, like Mirena or IUS. The copper IUD works by interfering with sperm mobility and fertilization, while the hormonal IUD releases progestin to prevent ovulation, thicken cervical mucus, and inhibit implantation of a fertilized egg. Both types offer long-term protection, with a failure rate of less than one percent, and upon removal, fertility returns quickly.
The copper IUD creates an inhospitable environment for sperm, preventing them from reaching the egg. Hormonal IUDs increase the viscosity of the cervical mucus, making it difficult for sperm to enter, and may also suppress ovulation. Though these devices have a high efficacy rate, users may experience increased menstrual bleeding and cramps, potential expulsion, or rare cases of uterine perforation.