Frequency or timing of unprotected intercourse within 14 days before IUD placement had no impact on pregnancy if a preplacement pregnancy test was negative, based on data from 655 women who received IUDs.
Many women present for emergency contraception with a history of unprotected intercourse, often beyond the 5-day guidelines for emergency contraception recommended by the World Health Organization, wrote Abena BakenRa, MD, of the University of California, Berkeley, and colleagues. “As such, we lack data on situations in which multiple episodes of unprotected intercourse occurred in the same menstrual cycle of use, especially episodes occurring more than 5 days before emergency contraception use,” the researchers said.
To determine pregnancy risk during a longer period before IUD placement, the researchers reviewed secondary data from a randomized trial of 655 women who received the copper T380A IUD or levonorgestrel 52-mg intrauterine system for emergency contraception. The women were aged 18-35 years and were enrolled at one of six family planning clinics in Utah between August 2016 and December 2019.
In a study published in Obstetrics & Gynecology, the researchers assessed pregnancies at 1 month after IUD placement. All of the women had a confirmed negative urine pregnancy test result immediately before IUD placement.
Overall, 286 women (43.7%) reported multiple episodes of unprotected intercourse, with a median of three episodes. A total of 95 women (14.4%) reported at least one unprotected intercourse episode at 6 days or more prior to IUD placement. No pregnancies were reported among women in either of these categories (0.0% for both). Pregnancy risk was 0.2% among those who reported unprotected intercourse within 5 days of IUD placement.
No pregnancies occurred in those who reported additional episodes of unprotected intercourse at 6-7 days, 6-10 days, or 6-14 days before IUD placement (0% for all).
In both the copper IUD and levonorgestrel groups, 68% and 74%, respectively, of the women reported that all fertile-window unprotected intercourse events occurred in the 5 days prior to IUD placement.
The study findings were limited by several factors including the lack of power for analysis of certain categories of assessment, such as pregnancy rates by timing or frequency, the inclusion of patients only from the state of Utah, and the potential underreporting of unprotected intercourse, the researchers noted. However, the findings were strengthened by the relatively large sample size, and by data on unprotected intercourse before IUD placement in a randomized, controlled trial that included two types of IUDs, they said.
“For these situations with multiple unprotected intercourse episodes and extended time between unprotected intercourse and emergency contraception request, potential users should be informed of the evidence of IUD emergency contraception efficacy, compared with the current state of uncertain data for oral emergency contraception methods,” the researchers said.
“Given the multitude of barriers that may impede timely presentation to care (insurance and cost concerns, difficulty finding a capable health care professional, or sexual assault trauma), these data are critical to patient-centered family planning care,” they concluded.