Progestin-Releasing IUDs and Ectopic Pregnancy

Andrew M. Kaunitz, MD


August 05, 2022

This transcript has been edited for clarity.

The end of Roe underscores the importance of highly effective contraceptives, including progestin-releasing intrauterine devices (IUDs).

Although few pregnancies of any type occur in women using these IUDs, when they do occur, the likelihood of an ectopic pregnancy (EP) is increased.

Full disclosure: My department receives research funding from Bayer, manufacturer of progestin IUDs, to support a clinical trial of an investigational medication for treatment of menopausal symptoms. In this video, I use brand names for clarity.

In the July issue of American College of Obstetrics and Gynecology's Green Journal (Obstetrics & Gynecology), investigators in Stockholm assessed the 1-year incidence of EP in women using full-size as well as smaller levonorgestrel (LNG) IUDs:

  • Mirena, a full-size IUD with 52 mg of progestin, is now approved by the FDA for up to 7 years of use.

  • Liletta, an essentially identical IUD, also contains 52 mg of LNG.

  • Kyleena, a smaller-frame IUD, contains 19.5 mg of progestin and is approved for up to 5 years of use.

  • Skyla, a second smaller-frame IUD with 13.5 mg of progestin, is approved for up to 3 years of use.

The 1-year overall pregnancy rates for these highly effective devices range from 0.2% to 0.4%.

The Stockholm investigators found that 1-year EP rates during use of these devices range from 1 in 10,000 to 1 in 1000, with Mirena having the lowest rate.

In the great majority of my parous patients choosing progestin IUDs, I place Mirena due to its high efficacy for contraception, predictable menstrual suppression, and long duration of action.

In some of my adolescent nulliparous patients, after shared decision-making, I place Kyleenas due to the smaller size of this IUD.

Occasionally, in women who have mood disorders with sensitivity to progestins but who would like to use a progestin IUD, I place Skyla as this release lower amounts of progestin than does Mirena or Kyleena.

Compared with women using no contraception or those using other reversible methods, the absolute risk for EP is lower in women using progestin IUDs.

Nonetheless, women opting for IUD placement should understand that in the unlikely event that they become pregnant, the risk of an EP is elevated, and timely evaluation, including vaginal ultrasound and assessment of quantitative serum HCG [human chorionic gonadotropin] levels, is appropriate.

The bottom line is that IUDs offer women highly effective contraception, an attribute more important than ever in the current post-Roe environment we practice in.

I am Andrew Kaunitz. Please take care of yourself, and each other.

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