A multiparous woman presented to the gynecology clinic requesting intrauterine contraceptive (IUC) placement (Figure). She was appropriately counseled on the risks and benefits of the IUC and at that visit had a normal Papanicolaou test and negative cultures for gonorrhea and Chlamydia trachomatis.
As instructed, she returned a week later while having menses for placement of a copper IUC. The gynecologist placed the IUC without difficulty and showed the patient how to palpate the IUC strings. One month later, the patient presented to the clinic because she was unable to find the strings. On pelvic examination, the gynecologist was also unable to locate the strings. A pelvic ultrasound revealed a 7-week intrauterine pregnancy and an IUC. By dates, the patient was approximately 3-4 weeks pregnant at the time of IUC insertion, and the “menses” was probably implantation bleeding.
The patient was referred to a perinatologist who recommended that the IUC remain in place. The patient subsequently had an elective termination of pregnancy without complication. As a result of this error, the clinic now requires urine human chorionic gonadotropin (HCG) testing prior to procedures in premenopausal women regardless of menstrual or sexual history.
Intrauterine contraceptives (IUC, a more precise and less pejorative term than the old term “IUD”) are more effective than sterilization operations at preventing pregnancy and do not cause infertility, a complication reported in older, flawed studies.(1,2) They are used by up to 30% of fertile women in some European countries but have fallen into disuse in the USA, where only approximately 1% of contraceptors use them because clinicians, concerned about infection and liability, often do not offer IUC to their patients. When inserted within 1 week of intercourse, the copper IUC is a highly effective “emergency contraceptive.” However, IUCs are not effective abortifacients and should not be inserted when a pregnancy is established in the uterus, as happened in the case described above.
Insertion during pregnancy is not common because most IUC placements are accomplished during menses when the cervix is more open and pregnancy unlikely. In this case, bleeding occurred despite an ongoing pregnancy; this can happen at some time in the course of up to 20% of pregnancies. Because bleeding can be present during pregnancy, some clinicians require a rapid urine pregnancy (HCG) test for all women requesting IUC insertion. These inexpensive tests are sensitive to 20 mIU/mL of HCG, a level typical of pregnancies at about the time of implantation. If a urine test were negative despite the presence of a fertilized egg, insertion of a copper, but not a hormonal, IUC would in all likelihood prevent implantation (that is, act as an “emergency contraceptive”).
Follow-up should occur approximately 1 month after IUC placement for all patients. The purpose is primarily to check for expulsion of the IUC at the menses after insertion, the most likely time for expulsion, as well as to reassure the new user about abnormal bleeding, which is common in the first 3 months after insertion. The follow-up visit provides an opportunity to discuss any early side effects and see if the patient has been able to feel the strings of the IUC—her only way to check for its presence. If strings cannot be identified, as occurred in this case, sonography is the most effective way to check for proper intrauterine position. Growth of the uterus during pregnancy will sometimes cause the IUC strings to retract into the cervix or uterus. The strings can usually be extracted from the cervix, but not the uterus, by twirling a cervical cytology brush in the canal.
If urine HCG and uterine sonography confirm that an IUC user is pregnant, the IUC should be removed immediately if the strings can be found regardless of whether she wants to continue the pregnancy. If the strings cannot be found, removal is more difficult and could disrupt the pregnancy, but there are case reports of successful pregnancies after sonographically guided removals.(3) Removal of the IUC substantially reduces the risk of subsequent spontaneous abortion no matter when during gestation the removal is accomplished. The presence of an IUC increases the risk of spontaneous abortion nearly three-fold, so, whether a pregnancy will be continued or not, the IUC should be removed as soon as possible because the risk of spontaneous abortion in the presence of an IUC increases as gestation progresses.(4-6) After removal of an IUC with visible strings, the spontaneous miscarriage rate is approximately 30%, compared with 20% if no IUC were present.(4-6) If the pregnancy is not aborted, an IUC does not adversely affect fetal development.(7-9) In this case, the strings could not be found, and the perinatologist recommended that the IUC remain in place.
This case describes how the clinic now requires urine HCG testing prior to intrauterine procedures in premenopausal women regardless of menstrual or sexual history. To avoid IUC insertion during pregnancy, performing sensitive, rapid urine pregnancy tests and waiting for presumed menses are reasonable and adequate measures to avoid IUC insertion into a pregnant uterus. Sonography during very early pregnancy can fail to detect a pregnancy and is not needed unless pregnancy is suspected or unless the position of the IUC is in doubt. IUCs reduce the risk of ectopic pregnancy because they usually prevent fertilization. The rare pregnancies that occur in IUC users are, however, more likely to be ectopic than in women who are not using contraception. If ectopic pregnancy is a possibility, pelvic sonography is indicated. Most clinics use checklists to help ensure that appropriate patients receive IUCs. However, these lists usually focus on past risks for pelvic infection and fail to acknowledge that IUCs do not threaten future fertility unless inserted through a cervix infected with organisms that can ascend from the contaminated uterus into the oviducts. Testing women for chlamydia with rapid amplified DNA tests can reduce this risk, since current chlamydia infection is the most important risk factor for post–IUC insertion infertility.(10) All patients should sign consent forms for IUC insertion because it is an invasive procedure sometimes requiring a cervical block with local anesthetic.
- If pregnancy is diagnosed with an IUC and the strings are accessible, remove the IUC immediately, whether or not the pregnancy may later be terminated, in order to reduce the risk of spontaneous abortion.
- IUCs are as effective in preventing pregnancy as sterilization operations, but they increase the risk of spontaneous abortion in the unusual situation of pregnancy with an intrauterine IUC.
- IUCs do not increase the risk of infertility even in young women who have never been pregnant.
- IUCs are not abortifacients because their primary action is to prevent fertilization, reducing the risk of ectopic pregnancies.
Philip Darney, MD, MSc Professor and Chief Obstetrics, Gynecology and Reproductive Sciences San Francisco General Hospital University of California, San Francisco
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Figure. Uterus with an Intrauterine Contraceptive (Illustration by Chris Gralapp)