An intrauterine device (IUD) use is an effective long-acting and reversible contraception method without the requirement of patient compliance. The IUD is placed inside the endometrial cavity and creates an unfavorable environment for implantation to occur. The prevention rate of pregnancy with the method is more than 99%.
Intrauterine devices are long-acting reversible contraception methods with significantly high success rates.
IUDs cause local inflammation in the uterine cavity and create an unfavorable environment for pregnancy development.
Copper-containing IUDs are one of the most commonly used contraceptive devices, effective for ten years.
The hormonal content of the Levonorgestrel-containing IUDs makes them useful in the management of abnormal uterine bleeding.
It should not be forgotten that, despite a very high success rate, IUDs do not provide 100% contraception and pregnancies are possible with an unexpired device.
Pregnancies with existing IUDs should be evaluated individually, and successful term pregnancies could be achieved without device removal.
History of IUD
The idea of an IUD in the form of pebble insertion into the camel uteri existed before the 20th century. However, presumably due to the limited knowledge of antiseption, high perinatal mortalities, and religious restrictions, it was not applied to humans until the early 1900s.
The first published information about IUDs dates back to 1909 in Germany when a ring made of silkworm gut was inserted into the human uterus by Dr. Richard Richter. Later, the silkworm gut was replaced by coiled metal rings composed of copper, nickel, or zinc, which in the literature is referred to as the Gräfenberg ring.
From the 1950s-1960s, several modified versions of IUDs, including polyethylene tubing, were tested among women in the United States, and in 1968 Food and Drug Administration approved the method for use in humans. Today, the use of intrauterine devices ranges from 2% to >40% among women aged 15-49 worldwide.
Types of IUD
IUDs act as a foreign body in the uterine cavity and initiate local inflammatory reactions. Despite continuous attempts to improve the quality of the device, two types of long-acting reversible methods, copper- and levonorgestrel-containing IUDs, are mainly used in clinical practice.
Copper-containing-IUDs (Cu-IUD) are T-shaped plastic devices wrapped with copper wire around the “arms” and “body.” Copper ions released from the device have toxic effects on spermatozoa, inhibiting sperm migration and viability, and embryos, further lowering the survival chances of the embryo reaching the uterine cavity. Moreover, the misconception that IUDs destroy already implanted embryos and, thus, cause the abortus doesn’t have evidentiary support. The device is effective for ten years, and only 0.08% of cases fail to prevent pregnancy.
Levonorgestrel-containing-intrauterine systems (LNG-IUS) are also T-shaped by appearance. However, unlike copper-containing devices, they contain levonorgestrel, a synthetic progestin hormone. Based on the total and daily released LNG doses, LNG-IUSs have several types. The high-dose LNG-IUSs contain 52 mg of total LNG and release 20 (Mirena) or 18.6 (Liletta) micrograms of hormone daily. Subsequently, low-dose LNG systems contain 19.5 and 13.5 mg of the hormone, releasing 17.5 and 13.5-14 micrograms/day of levonorgestrel, respectively. Daily released LNG acts as progesterone hormone and thickens the cervical mucus, thus reducing sperm access to the uterine cavity. A single IUD is effective for three to five years, and only 0.02% of cases are associated with contraceptive failure.
Who can use an IUD?
Intrauterine contraception is a good option for adolescents and adult women desiring a single, highly effective, reversible, and long-term method. The younger age does not disqualify adolescents from the IUD placement. The American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG) recommend this method to individuals younger than 18 years old. It was shown that adolescents without previous sexual experience may have unsuccessful IUD insertion compared to their sexually-active counterparts.
Nulliparous women without a previous pregnancy history are also eligible for IUD use. Notably, they report a higher frequency of pain during the IUD placement than multiparous women.
Indications for the IUD administration
Cu-IUD: The main indication for Cu-IUD insertion is the patient’s desire for long-term contraception. IUD placement may be planned immediately postpartum or delayed to the postpartum 4th-6th week. Although off-label, IUDs have also been used for emergency contraception within five days following unprotected sexual activity.
LNG-IUS: All three LNG-containing devices have equal contraceptive effects. However, the high-dose version of the device (52mg) is also approved for local hormonal effects, including the treatment of abnormal uterine bleeding and endometrial protection during hormonal replacement therapy.
Who shouldn’t use an IUD?
Women with suspicion or diagnosis of pregnancy, uterine or cervical malignancies, sexually transmitted infection (STD), or acute pelvic inflammatory disease (PID) are not eligible for IUD placement.
Moreover, congenital uterine abnormalities distorting the uterine anatomy, abnormal uterine bleeding, and conditions increasing pelvic infection risk are among the contraindications for IUD use. Needless to say, this method couldn’t be considered a contraceptive method for one with a history of previously inserted and unremoved IUD or allergy to any component of the device.
Additionally, LNG-IUS couldn’t be used in women with breast or any other progesterone-sensitive cancer suspicion or diagnosis due to the hormone content.
When to remove your IUD
IUDs are reversible contraceptive methods. Therefore, a desire for pregnancy is one of the reasons for the device removal. Moreover, any adverse effects affecting the patient’s quality of life, including pelvic pain or discomfort, irregular and heavy vaginal bleeding, and the expiration date of the IUD, should be considered for the device removal. Additionally, LNG-IUSs should be removed in cases with diagnosed cervical or uterine malignancies.
Although minimal, given the failure risk of the method, cases with confirmed intrauterine pregnancy and a visible string of the device from the cervical os also should be evaluated for the device removal. If left in place, the IUD may increase the spontaneous miscarriage risk to 40-50%. At the same time, it should be noted that the existence of an IUD in the uterus doesn’t cause defects or malformations in an unborn fetus.
IUDs are highly effective reversible long-term contraceptive methods.
Adolescents and adult women are suitable candidates for IUD contraception.
The most commonly used IUDs, copper, and levonorgestrel-containing devices are approved for continuous five- and 10-year use.
Anatomical and physiological conditions affecting the proper insertion and survival of the device in the uterine cavity are contraindications for the use.
Pathologies associated with the copper or progestin content of the device also should be considered for patient eligibility.