The Device
There are only two types of intrauterine devices (IUDs), available for women, for use as contraception. Both devices are T-shaped and are inserted into a woman's uterus. While in place, the IUD keeps sperm from making its way to a woman's egg. If sperm cannot join an egg, fertilization cannot take place. During the placement of an IUD, there is a risk of introducing bacteria into the uterus. IUDs can also dislocate from the uterus and pierce the uterine wall. Fertility will resume as it was before the IUD, once the device has been removed. A doctor can withdraw the device by pulling on the string that is attached.
Hormone IUD
Mirena IUD, contains progestin. Progestin prevents the ovaries from releasing an egg. If an egg does not drop into the uterus, then sperm cannot fertilize it. Progestin also thickens the cervical mucus to keep sperm from traveling up the vagina and to an egg. Sperm will die after being trapped in the mucus. Because Mirena contains hormones, it has the potential for reducing menstrual cramping and reducing blood flow. A Mirena IUD can be left in place for up to five years. According to Mayo Clinic, it has an efficacy rate of 99.9 percent.
Copper IUD
According to Mayo Clinic, ParaGard IUD releases copper while it is in place in the uterus. Copper can inactivate sperm while it is traveling through cervical mucus. According to ParaGard, this IUD is 99.2 to 99.4 percent effective and can remain within the body for up to 10 years. Women with a copper allergy should not use a ParaGard IUD. According to ParaGard, this device may cause heavier bleeding and stronger cramps during menstruation.
