Cases & Commentaries
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
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
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
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
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
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
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
All patients should sign consent forms for IUC insertion because it
is an invasive procedure sometimes requiring a cervical block with
- 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