Intrauterine Contraception

(Updated June 2014)

Description

Intrauterine contraception (IUC), also referred to as an intrauterine device (IUD) or intrauterine system (IUS), is a long-acting reversible contraceptive method that involves the placement of a small T-shaped device inside the uterus. Four IUC methods are available: the Copper T 380A (brand name ParaGard^®) and three levonorgestrel intrauterine systems (LNG 52 IUS, brand name Mirena^®; LNG 13.5 IUS, brand name Skyla^®; and LNG 52 IUD, brand name Liletta^TM). Because IUCs use either non-hormonal ingredients or progestin to prevent fertilization, they are a good contraceptive choice for women who cannot use estrogen. IUDs have one of the highest satisfaction and continuation rates among patients.³³

Copper T IUD

• The Copper T IUD contains polyethylene with copper along the vertical stem and horizontal arms.
• A polyethylene string is secured to the device, allowing for easy removal.
• The Copper T IUD is approved for 10 years of use, although studies have shown it to be effective for as long as 20 years.⁶⁸
• The device causes an immune response that creates a hostile environment for sperm, thereby preventing fertilization of an ovum.
• In addition, it appears that the device also disrupts the normal division of oocytes and the formation of fertilizable ova.⁶⁹

LNG IUS

• Once placed in the uterus, the LNG 52 IUS (Mirena^®) initially releases 20 mcg LNG/day; the rate decreases progressively to 10 mcg/day after 5 years.
• The LNG 13.5 IUS (Skyla^®) initially releases 14 mcg/day; the rate decreases to 6 mcg/day after 3 years.
• The LNG IUS thickens the cervical mucus and inhibits sperm motility and function.⁷³
• The endometrial atrophy caused by the high LNG levels leads to a substantial decrease in menstrual flow and absence of bleeding in some women.

Use

Copper T IUD

• The Copper T IUD can be used off-label as emergency contraception. It can be inserted up to 5 days after unprotected intercourse and reduces the risk of pregnancy by more than 99%.⁷¹

LNG IUS

• The LNG 52 IUS (Mirena^®) is approved for 5 years of use, although data demonstrate that it is effective for up to 7 years.⁷²
• The LNG 13.5 IUS is approved for 3 years of use.⁷³
• The LNG 52 IUS (Liletta^TM) is approved for 3 years of use.

Effectiveness

• IUC is extremely effective.
• The Copper T IUD is effective immediately after insertion and has a failure rate of 0.8 percent with typical use.¹⁹
• The LNG 52 IUS (Mirena^®) is effective 7 days after insertion and has a failure rate of 0.2 percent with typical use.¹⁹
• If the LNG 13.5 IUS (Skyla^®) or LNG 52 IUS (Mirena^®) is inserted during the first seven days of the menstrual cycle or immediately after a first trimester abortion, then back-up contraception is not needed.

Risks

• Complications associated with IUC include uterine perforation during the insertion procedure.
• Expulsion of the LNG 52 IUS occurs in 2 to 10 percent of users within the first year.⁵⁶ In clinical trials, the 3-year expulsion rate for LNG 13.5 IUS was 3.2%.⁷³
• Expulsion may be more common in nulliparous women.⁵⁶
• Because bacteria may be introduced into the uterus during IUC insertion, there is a slight increased risk of infection during the first month of use.
• IUC poses no increased risk of infections (i.e or PID-associated infertility) beyond the first month of use.⁷⁴
• Providers can consider obtaining gonorrhea and chlamydia cultures for women at risk of STIs at the time of IUC insertion. If results are positive, antibiotic treatment should be started, but there is usually no need to remove the device.³⁹

Side Effects

The copper-containing IUD increases the duration and amount of menstrual bleeding, resulting in approximately 50 percent greater blood loss.^75-77

For LNG IUS users, bleeding patterns are unpredictable, with frequent light bleeding for the first 3 months after insertion.⁷⁸ By 3-6 months, most women who use LNG 52 IUS (Mirena and Liletta) experience dramatically reduced bleeding. About one-third of women will have amenorrhea after 12 months.⁷⁹ In clinical trials, amenorrhea developed in approximately 6% of LNG 13.5 IUS (Skyla) users at one year.⁷³

Contraindications and Precautions

Copper T IUD

Advantages of IUC

• Long-term method (10 to 20 years for Copper T IUD; 5 to 7 years for LNG 52 IUS; 3 years for LNG 13.5 IUS)
• Discreet
• Extremely effective
• After up-front cost, cost-effective for term of use
• Rapid return to fertility after removal
• Can be inserted any time during menstrual cycle when pregnancy can be excluded
• Can be inserted immediately after abortion or delivery (i.e., after placenta is delivered) or as long as 4 weeks afterward
• Lack of estrogen makes IUC appropriate for smokers older than age 35, postpartum women who are breastfeeding, and others with contraindications to estrogen.
• LNG 52 IUS may reduce menstrual symptoms in women who have uterine fibroids or adenomyosis^80,81 and may reduce menstrual blood loss in women at risk for anemia. LNG 13.5 IUS (Skyla^®) does not carry the same indication for dysmenorrhea.⁷³
• Copper T IUD provides a hormone-free option for women.

Disadvantages

• Requires visit to trained clinician for insertion and removal
• Some risk of expulsion within first year
• No protection against STIs

Counseling Messages

• IUC is an excellent contraceptive choice for women who desire a highly effective and long-term but reversible method of contraception.
• Women who want reassurance about the placement of the IUD can check for presence of the string, although checking on a regular basis is not necessary.
• It is important for women to be aware of the warning signs of expulsion and infection.
• Follow-up visits after IUC insertion are important.
• If the LNG 13.5 IUS (Skyla^®) is inserted during the first seven days of the menstrual cycle or immediately after a first trimester abortion, then back-up contraception is not needed.⁷³ The same is true for LNG 52 IUS (Mirena^®).
• This method does not protect against STIs.