Should return to fertility be a concern for nulliparous patients using an IUD?

Investigators from the University of Texas Southwestern are dispelling the myth that you shouldn’t recommend intrauterine devices (IUDs) for nulliparous women because the devices might make it more difficult for them to become pregnant after discontinuation. They found that nulliparous women can just as easily get pregnant after using a progestin intrauterine system (IUS) as parous women,¹ according to results of a study presented at the American Society for Reproductive Medicine (ASRM) 2018 annual meeting (October 6–10, Denver, Colorado).

Bruce R. Carr, MD, lead investigator of the study, explained in an interview with OBG Management, “There have been a number of studies—maybe 10 to 15 years ago—that looked at pregnancy rates when patients stopped using IUDs, but most of these studies were done in women who were multiparous. There is almost no data on patients who are nulliparous stopping an IUD and trying to get pregnant.”

Participants and methods. This prospective, multicenter, clinical trial, which is still ongoing, is evaluating the efficacy and safety for up to 10 years of the Liletta levonorgestrel 52-mg IUS in nulliparous and parous women ages 16 to 45 years. Every 3 months for up to 1 year, the investigators contacted the women who discontinued the IUS during the first 5 years of use and who were trying to become pregnant to determine pregnancy status.

Outcomes. The primary outcome was time to pregnancy among nulliparous vs parous women after discontinuation of a progestin IUS.

Findings. Overall, 132 (87%) of 152 women ages 16 to 35 years at the beginning of the study who attempted to become pregnant did so within 1 year of discontinuing the IUS, and there was no difference in pregnancy rates between nulliparous and parous women (87.5% vs 86.1%, respectively; P<.82) or between nulligravid and gravid women (88.2% vs 85.7%, respectively; P<.81). High percentages of women became pregnant by the end of 3 months (43.4%) and 6 months (69.7%), with a median time to conception of 91.5 days. The women used the IUS for a median of 34 months before discontinuation. Length of IUS use and age of the women at IUS discontinuation did not affect pregnancy rates at 12 months postdiscontinuation in either nulliparous or parous women (TABLE).¹

“The bottom line,” according to Dr. Carr, is that the “pregnancy rates were the same in women who had never been pregnant compared with women who had previously been pregnant.” He continued, “People worried that if a patient who had never been pregnant used an IUD that maybe she was going to have a harder time getting pregnant after discontinuing, and now we know that is not true. It [the study] reinforces the option of using progestin IUDs and not having to worry about future pregnancy.”

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This article was updated October 15, 2018.