Intrauterine devices (IUDs) stay in the uterine cavity and are made of plastic, polyethylene contain barium sulfate, to make them radiographic. A sterile spermicidal inflammatory reaction is caused so very few sperm can reach the oviducts, not allowing fertilization to occur. If fertilization did occur, implantation is prohibited due to the effect that IUDs have on the endometrium.

Types of intrauterine devices

• ParaGard is a copper-containing IUD with an efficacy lasting 10 years.
• Mirena is a progestin-releasing IUD which must be replaced every 5 years. The failure rates of intrauterine devices range from 1-3%. Experienced physicians can have lower failure rates due to performing correct high-fundal insertion.

Advantages of IUD 

The advantages of intrauterine devices include the ability to return to fertility after removal and are also an option for women who are unable to take estrogen. They also lack systemic side effects, have immediate high efficacy, single motivational act, and lack interference with lactation.

Disadvantages of IUD

The disadvantages of an IUD are they can lead to a slight increase risk of infection during the month following insertion, an increase in menstrual bleeding and cramps, and expulsion and perforation of the uterine fundus.

Pregnancy with Intrauterine Devices

Pregnancies can occur with the IUD in place, which causes a 55% risk of spontaneous abortion. IUDs also lead to a higher chance of having an ectopic pregnancy. Prematurity is also a risk of about 12-15% while the IUD is in situ.

Intrauterine Devices Contraindications

Contraindications to intrauterine devices include various conditions related to pregnancy, pelvic inflammatory disease, and the uterus. You are to be cautious when using an IUD if you are suspected of being pregnant or known to be and should have it removed. You should also be cautious if you have had a previous ectopic pregnancy. You should also be wary of using an IUD if you are at high risk for pelvic inflammatory disease or a partner that has multiple sexual partners. Other conditions include untreated acute cervicitis or vaginitis, conditions that have increased susceptibility to infections, postpartum or postabortal endometritis in the past 3 months, undiagnosed abnormal genital bleeding, distorted uterine cavity from leiomyomata, uterine anomalies or known or suspected cervical or uterine malignancy, including an unresolved abnormal Pap smear.