Pregnancy test missed before IUD placement? Your liability.

Medical considerations

First, some background information on Mirena.

Indications for Mirena

Here are indications for Mirena¹:

• intrauterine contraception for up to 5 years
• treatment of heavy menstrual bleeding for women who choose to use intrauterine contraception as their method of contraception.

Prior to insertion, the following are recommended²:

• a complete medical and social history should be obtained to determine conditions that might influence the selection of a levonorgestrel-releasing intrauterine system (LNG IUS) for contraception
• if indicated, perform a physical examination, and appropriate tests for any forms of genital or other sexually transmitted infections
• there is no requirement for prepregnancy test.

Contraindications for Mirena

Contraindications for Mirena include²:

• pregnancy or suspicion of pregnancy; cannot be used for postcoital contraception
• congenital or acquired uterine anomaly including fibroids if they distort the uterine cavity
• acute pelvic inflammatory disease or a history of pelvic inflammatory disease unless there has been a subsequent intrauterine pregnancy
• postpartum endometritis or infected abortion in the past 3 months
• known or suspected uterine or cervical neoplasia
• known or suspected breast cancer or other progestin-sensitive cancer, now or in the past
• uterine bleeding of unknown etiology
• untreated acute cervicitis or vaginitis, including bacterial vaginosis or other lower genital tract infections until infection is controlled
• acute liver disease or liver tumor (benign or malignant)
• conditions associated with increased susceptibility to pelvic infections
• a previously inserted IUD that has not been removed
• hypersensitivity to any component of this product.

Is Mirena a postcoital contraceptive?

The American College of Obstetricians and Gynecologists (ACOG) bulletin on long-acting reversible contraception states “the levonorgestrel intrauterine system has not been studied for emergency contraception.”³ Ongoing studies are comparing the levonor‑gestrel IUD to the copper IUD for emergency contraception.⁴

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Accuracy of home pregnancy tests

Although the first home pregnancy test was introduced in 1976,⁵ there are now several home pregnancy tests available over the counter, most designed to detect urinary levels of hCG at ≥25 mIU/mL. The tests identify hCG, hyperglycosylated hCG, and free Betasubunit hCG in urine. When Cole and colleagues evaluated the validity of urinary tests including assessment of 18 brands, results noted that sensitivity of 12.4 mIU/mL of hCG detected 95% of pregnancies at time of missed menses.⁶ Some brands required 100 mIU/mL levels of hCG for positive results. The authors concluded “the utility of home pregnancy tests is questioned.”⁶ For urinary levels of hCG, see TABLE.

Pregnancy with an IUD

The gynecologist’s concern about pregnancy when an IUD is inserted was valid.

With regard to pregnancy with Mirena in place, the full prescribing information states²:

Intrauterine Pregnancy: If pregnancy occurs while using Mirena, remove Mirena because leaving it in place may increase the risk of spontaneous abortion and preterm labor. Removal of Mirena or probing of the uterus may also result in spontaneous abortion. In the event of an intrauterine pregnancy with Mirena, consider the following:
Septic abortion
In patients becoming pregnant with an IUD in place, septic abortion - with septicemia, septic shock, and death may occur.
Continuation of pregnancy
If a woman becomes pregnant with Mirena in place and if Mirena cannot be removed or the woman chooses not to have it removed, warn her that failure to remove Mirena increases the risk of miscarriage, sepsis, premature labor and premature delivery. Follow her pregnancy closely and advise her to report immediately any symptom that suggests complications of the pregnancy.

Concern for microbial invasion of the amniotic cavity must be considered. Kim and colleagues addressed pregnancy prognosis with an IUD in situ in a retrospective study of 12,297 pregnancies; 196 had an IUD with singleton gestation.⁷ The study revealed a higher incidence of histologic chorioamnionitis and/or funisitis when compared with those without an IUD (54.2% vs 14.7%, respectively; P<.001). The authors concluded that pregnant women with an IUD in utero are at very high risk for adverse pregnancy outcomes. Brahmi and colleagues⁸ reported similar risks with higher incidence of spontaneous abortion, preterm delivery, and septic abortion.

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Efficacy and safety concerns with emergency contraception

The efficacy and safety of emergency contraception using levonorgestrel oral tablets (Plan B One-Step; Duramed Pharmaceuticals) is another concern. Plan B One-Step should be taken orally as soon as possible within 72 hours after unprotected intercourse or a known or suspected contraceptive failure. Efficacy is better if Plan B is taken as soon as possible after unprotected intercourse. There are 2 dosages: 1 tablet of levonorgestrel 1.5 mg or 2 tablets of levonorgestrel 0.75 mg. The second 0.75-mg tablet should be taken 12 hours after the first dose.⁹

Plan B can be used at any time during the menstrual cycle. In a series of 2,445 women aged 15 to 48 years who took levonorgestrel tablets for emergency contraception (Phase IV clinical trial), 5 pregnancies occurred (0.2%).¹⁰

ACOG advises that emergency contraception using a pill or the copper IUD should be initiated as soon as possible (up to 5 days) after unprotected coitus or inadequately protected coitus.⁹

Retained products of contraception

ACOG Practice Bulletin No. 135 on complications associated with second trimesterabortion discusses retained POC.¹¹ The approach to second trimester abortion includes dilation and evacuation (D&E) as well as medical therapy with mifepristone and misoprostol. D&E, a safe and effective approach with advantages over medical abortion, is associated with fewer complications (up to 4%) versus medical abortion (29%); the primary complication is retained POC (placenta).¹¹

Read about the legal considerations of this case.