Please note: This archive was last updated in 2005.

RHO archives : Topics : Contraceptive Methods

Intrauterine Devices

Overview

Intrauterine devices (IUDs) are small flexible devices made of metal and/or plastic that prevent pregnancy when inserted into a woman's uterus through her vagina. Nearly 15 percent of women of reproductive age—approximately 160 million women—currently use IUDs. Much of their popularity stems from their effectiveness combined with their long duration. The most widely used IUDs are copper-bearing IUDs. Inert (unmedicated) and progestin-releasing IUDs (levonorgestrel or progesterone) are less widely available. IUDs are a safe and effective method of reversible, long-term contraception for most women. They do not affect breastfeeding, interfere with intercourse, or have hormonal side effects; only some gynecologic and obstetric conditions and infections preclude use of the method. One drawback of IUDs is their tendency to cause heavy menstrual bleeding. Unless otherwise stated, the following information applies to copper IUDs.

Top of page 

Characteristics of IUDs

Effectiveness

0.4% to 2.5% failure rate for copper IUDs and 0.1% failure rate for the levonorgestrel-IUD during the first year of typical use.

Age limitations

No restrictions on use for women age 20 and over.

Parity limitations

No restrictions on use for parous women; nulliparous women can generally use IUDs if they do not have a history of pelvic infection, a previous ectopic pregnancy, or multiple sex partners (or partner who has other partners).

Mode of action

Through a combination of mechanisms: inhibiting sperm migration in the upper female genital tract, inhibiting ovum transport, and stimulating endometrial changes.

Effect on STI risk

Not protective.

Drug interaction

None.

Duration of use

The Copper T 380A device remains effective for up to 10 years; the Multi-load copper IUD remains effective for up to five years; the levonorgestrel-releasing IUD is effective for at least five years. Most women can use IUDs safely throughout their reproductive years (if the woman is satisfied with the method and has no problems with it).

Return to fertility

Immediately upon removal.

Top of page 

Key issues

The intrauterine device is one of the most commonly used methods of fertility regulation, especially in developing country programs. It is a safe and effective method for women who are in a monogamous sexual relationship and not at risk of sexually transmitted infections (PATH/Outlook 1992; FHI 2000; IPPF 2003). WHO estimates that more than 150 million women use IUDs, with more than 74 million users in China alone. A review of studies confirmed that: (1) IUDs are not abortifacients; (2) newer comprehensive IUDs are highly effective and long-lasting; (3) IUDs can be safely used by lactating women; and (4) IUD use is not associated with an increased risk of pelvic inflammatory disease (PID), of ectopic pregnancy, or of subsequent infertility (Chi 1993).

Since the 1970s, WHO has conducted 10 large trials to compare and evaluate the safety and efficacy of six different IUDS (WHO, 2002). One trial began in 1989 to compare the Copper T 380A and the Multiload-375; it involved nearly 4,000 women in eight countries. Although all the modern IUDs are very effective at preventing pregnancy, this long-term comparison found that the Copper T380A was nearly twice as effective as the Multiload-375, with reported pregnancy rates of 3.4 versus 5.4 percent after 10 years (WHO 2002).

IUDs and Pelvic Inflammatory Disease

The most definitive review of IUD safety, particularly regarding PID, is the World Health Organization review of 12 studies involving nearly 23,000 IUD users around the world (Farley 1992). That study found that, overall, the rate of PID among IUD users was very low; the PID rate was highest during the first 20 days after insertion and was low and stable after that, even among users who had an IUD in place for eight years or more. PID among IUD users was found to be most strongly related to the insertion process rather than the IUD.

Efforts by the Technical Guidance Working Group, a panel of family planning experts from around the world, has helped refine key precautions that will help IUD providers minimize PID risk during insertion. Chief among these are client screening and aseptic insertion technique (FHI 1996). Results of a randomized clinical trial in Nigeria found that use of a systemic antibiotic at the time of IUD insertion did not significantly reduce the incidence of PID during the first three months of IUD use. Careful screening of IUD candidates and sterile insertion technique were suggested as more cost-effective interventions to control IUD-related PID than use of expensive antibiotic therapy (Farley 1992).

A recent review of the issue of antibiotic prophylaxis for IUD insertion by the Cochrane Library (Grimes and Schulz 2002) confirmed that use of either 200 mg of doxycycline or 500 mg azithromycin taken orally before IUD insertion confers little benefit. Although use of prophylactic antibiotics before IUD insertion produced a marginally significant reduction in the likelihood of an unscheduled visit to the provider, no other benefits were observed. A uniform finding in the studies was the low risk of IUD-related infection, with or without use of antibiotic prophylaxis.

New Generation of IUDs

The newest generations of copper IUDs combine high continuation rates with very low pregnancy rates (JHU/CCP 1995). Since little can be done to increase the efficacy of these devices, recent research has focused on developing devices to address side effects, particularly bleeding and pain, which account for a significant number of removals. The levonorgestrel-releasing IUD, a device with high effectiveness and acceptability, reduces menstrual blood loss compared to pre-insertion levels (Luukkainen 1995). The levonorgestrel-releasing IUD, Mirena, has been available in Europe for 10 years and has been used by 2 million women; it was approved for sale in the United States in December 2000. Frameless IUDs, such as the Gynefix (Kishen 1998; Van Os 1998; Wildermeersh 1999) have been specifically designed to reduce cramping and pain. This device consists of a surgical nylon thread that holds copper sleeves and is anchored to the uterine fundus during insertion. It recently became available in Europe, and is licensed for five-year use. Studies suggest that the Gynefix is as effective as the Copper T380A, and expulsion rates are less than 1 per 100 women years.

Continuing Research

Other research has looked at improving IUD services by training non-physicians to provide IUDs. IUD insertions by trained non-physicians is increasing, and some countries, such as the Philippines, have initiated training programs specifically for non-physicians. Studies in Brazil, Turkey, and the Philippines found that trained health care workers can provide IUDs as safely and effectively as physicians in many settings (Farr 1998). Additional training may be required to ensure correct placement of the IUD in the uterine fundus to reduce the likelihood of expulsions. Training non-physicians to provide IUDs safely and effectively could result in higher use of this method. Recent studies also have investigated the possibility that the increased menstrual bleeding and upper genital tract infections associated with IUDs may increase the risk of HIV among IUD users. Data from several studies, however, have not demonstrated an increased risk (Mati 1995; Martin 1998). IUDs generally are not recommended for women at risk of any STI, including HIV (PATH/ Outlook 1999).

Also see Hormonal Contraception, IUDs, and HIV Risk.

Return to Method Summaries page     Top of page