Intrauterine Devices: Separating Fact From Fallacy

, Magee-Womens Hospital, University of Pittsburgh School of Medicine

In This Article


Infection. The most serious complication associated with IUDs is infection. Early analyses suggested that IUDs might cause pelvic inflammatory disease (PID). These studies, however, often included only women with IUDs who had been hospitalized. Furthermore, these biased studies included controls who were using barrier methods of contraception (which decreased their risk of sexually transmitted diseases and PID). More recent analyses of these data have removed confounding factors and found no increased risk of PID in monogamous women.[7,8,9]

To understand the risk of pelvic infection with an IUD, one must first understand how clinical infection occurs. The bacterial milieu of the vagina sits in a steady-state equilibrium in women who are in long-standing, mutually monogamous relationships. External factors can change in this vaginal environment. For example, a vaginal yeast infection frequently occurs after treatment with systemic antibiotics that kill some of the normal bacteria inhabiting the vagina, allowing an overgrowth of yeast. Similarly, changes in a woman's vaginal milieu occur just from the introduction of a new male partner (penis) or from sex with a steady partner (male) after he has had intercourse with another partner. Moreover, a lack of monogamy on the part of either partner can introduce a sexually transmitted organism. Thus, a nonmonogamous relationship can change the bacterial equilibrium or introduce a sexually transmitted organism. Either of these can result in PID.

Infections that are truly related to the IUD are a result of insertion; in other words, contamination of the uterine cavity with organisms from the vaginal flora occurs at the time the IUD is inserted. Still, this risk is minimal (0.97%) and is limited to the first 20 days after insertion.[10] Antibiotic prophylaxis with doxycycline, 200mg administered orally 1 hour prior to insertion, has been evaluated and shown to be of no benefit to these women.[11]

Infections that occur more than 20 days after insertion are likely to be sexually transmitted. Because sexual behavior is an important factor in the pathogenesis of PID, women who are at low risk for STD are unlikely to experience upper tract infection while using an IUD. Women who have cultures positive for gonorrhea and/or chlamydia without evidence of upper tract infection should be treated appropriately. Though IUD removal is not mandatory in women who develop an STD, it is strongly advised. Patients who use an IUD and develop an STD should be counseled that the high-risk sexual behavior that led to the STD could result in PID, possibly leading to infertility and chronic pelvic pain. Should any signs of upper tract disease be present, the IUD should be removed and appropriate antibiotic therapy instituted.

Papanicolaou (Pap) smears after insertion may include a report of the presence of Actinomyces-like organisms. The frequency of such reports ranges from less than 1% to 25% of IUD users, depending mainly on how hard the cytologist looks for the organisms, the duration of IUD use, and the type of IUD.[12,13]Actinomyces-like organisms are more frequently found with inert plastic-only devices and less frequently with copper-containing devices (<1%). Though rare, intraabdominal[14,15,16] and metastatic and disseminated[17,18] Actinomyces infections in association with IUD use have been reported.

For a patient with a Pap smear consistent with Actinomyces, the clinician may wish to review the slide with a cytopathologist to confirm the findings. There is no direct evidence that presence of Actinomyces on a Pap smear requires antibiotic treatment or IUD removal. If PID is suspected or the clinician believes antibiotic therapy is necessary, the patient can initially be treated without IUD removal. The antibiotic of choice is penicillin VK 500mg orally 4 times daily for 1 month. One month after completion of treatment, the Pap smear should be repeated. If Actinomyces is still present or recurs, the IUD may need to be removed. At this point, it is important for the clinician to review with the patient her relative risk of developing pelvic actinomycosis and the risks and benefits of other options of contraception available to her, and to decide whether it is better to leave the IUD in place or remove it and use another method of contraception. If the patient had been using a progesterone-releasing IUD, and she has no contraindications to a copper-containing IUD, then switching to a copper-containing IUD may be a reasonable option. Such a patient should still be followed closely for recurrence of Actinomyces.

Pregnancy. If a woman who has an IUD in place becomes pregnant, the clinician should immediately suspect ectopic pregnancy. Copper-containing IUDs are associated with a much lower ectopic pregnancy rate than progesterone-releasing IUDs. About 6% of IUD pregnancies are extrauterine with a ParaGard, and 24% with a Progestasert. Because IUDs protect against all types of pregnancy, it is the relative risk of pregnancy compared with the failure to use any method that is important. The relative risk of ectopic pregnancy for a woman using the ParaGard is approximately one tenth that of noncontraceptors; with the Progestasert the risk is approximately 50% to 80% greater than for women not using contraception.[19] In 8000 women-years of experience in randomized multicenter trials with the ParaGard, there has been only 1 reported extrauterine pregnancy.[20] The protection against ectopic pregnancy afforded by the copper-containing IUDs makes their use acceptable in women with prior ectopic pregnancy who are otherwise good candidates for an IUD.

Spontaneous abortion is a more likely complication of pregnancy with IUD use than is ectopic pregnancy. The spontaneous abortion rate for women wearing IUDs is approximately 50%, versus approximately 15% for all pregnant women.[21] Because of the high risk for spontaneous abortion, IUDs should be removed if pregnancy is diagnosed and either the retaining or indicator string is visible. After removal of an IUD with visible strings, the spontaneous abortion rate decreases to about 30%.[22] If an IUD is left in place, the relative risk of premature birth is increased 3- to 4.5-fold.[22,23,24] However, leaving an IUD in place will not raise the risk of birth defects.[25,26]

Historically, pregnancies that occurred despite the presence of the device or that were conceived before IUD insertion were more likely than other pregnancies to result in septic abortion, especially in the second trimester. However, data from 2 large cohort studies indicate no increased risk of septic abortion in women using the currently available IUDs.[26,27] If a woman that is pregnant with an IUD in place shows evidence of uterine infection, therapeutic abortion and removal of the device should be undertaken after initiation of antibiotic therapy.

Pain and bleeding. Although infection and ectopic pregnancy cause the most serious IUD complications, bleeding and pain are the symptoms most often responsible for removing an IUD. An estimated 5% to 15% of women discontinue IUD use within 1 year because of these symptoms.[28] Patients can experience metrorrhagia, menorrhagia, or both. Because IUDs can alter menstrual patterns, the clinician must take a careful menstrual history before discussing with a woman whether or not an IUD is appropriate. Women who experience heavy and prolonged menses or dysmenorrhea may not tolerate copper-containing IUDs, but may benefit from progesterone-releasing IUDs, which actually decrease menstrual blood loss. Cramping pain is generally limited to the first few months of IUD use. Abnormal bleeding or spotting and cramping can be treated with nonsteroidal analgesics (NSAIDs). It is common to recommend to patients that, with the onset of the first menstrual period after IUD insertion, NSAIDs be taken for the first few days around the clock.

Perforation/expulsion. Most commonly, perforations are related to insertion and clinician experience. Perforation of the uterus is rare when IUDs are inserted by clinicians who are experienced in the procedure, occurring only in approximately 0.1% of cases. Frequently, perforation during insertion is caused by the failure to properly assess the uterine position and to accurately define the cervical canal. Rarely do such perforations cause injury to the pelvic or abdominal organs. Often, perforation goes undetected until a routine gynecologic examination, when the device is noted to be absent. Unless there is excessive bleeding suggesting laceration of a uterine vessel, removal of the perforating IUD from the abdominal cavity should be done promptly, but it is not an emergency.

If a patient cannot detect an IUD string, this may indicate perforation or expulsion. Generally, the patient should be assured that the inability to feel a string most commonly means that the strings have retracted and not that the IUD has perforated the uterus or been expelled. The inability to visualize the strings in the cervical canal, especially if the retaining string was cut too short, is a common problem at IUD follow-up visits. Gently rotating a cytologic brush within the cervical canal will often help identify the strings. Should this fail to detect the IUD strings, the clinician must suspect either undetected perforation at the time of insertion or undetected expulsion.

The position of the IUD is then best determined by ultrasound or, if that is not available, with anteroposterior, lateral, and oblique films of the pelvis with a radio-opaque marker (ie, a uterine sound) in the uterine cavity. If the IUD is found to be in the uterine cavity, the patient and clinician can be reassured. A partially perforated or embedded IUD should be removed; this can be accomplished via hysteroscopy or with cervical dilation and use of ring forceps under ultrasound guidance. The latter can be done in the office with cervical anesthesia. An IUD that is partially perforated and cannot be removed transcervically or that perforates into the abdominal cavity will require removal by laparoscopy. Adhesion formation in the abdominal cavity will occur within 3 days after the perforation occurs, so prompt attention is needed.[29] Laparotomy is hardly ever necessary except in the rare event of organ damage requiring extensive repair.


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