Emergency Contraception: A Copper IUD May Be the Best Choice
Abstract & Commentary
By Jeffrey T. Jensen, MD, MPH, Editor
Synopsis: Women presenting for emergency contraception were offered a copper IUD or Plan B. Those who chose an IUD had a lower cumulative risk of unintended pregnancy at 1 year.
Source: Turok DK, et al. Emergency contraception with a copper IUD or oral levonorgestrel: An observational study of 1-year pregnancy rates. Contraception doi: 10.1016/j.contraception.2013.11.010.
The authors performed a prospective observational study to investigate 1-year pregnancy rates among women who present for emergency contraception. Women presenting to two family planning clinics in Utah requesting emergency contraception received scripted counseling information about use of the copper T380 IUD and single-dose oral levonorgestrel (LNG) 1.5 mg. Eligible subjects with no contraindications to either method who consented to participate were allowed to choose either method. The primary outcome was the unintended pregnancy rate for the 1 year after enrollment, and the sample size was selected to detect a 6% difference between the methods. A total of 542 women met all inclusion criteria and consented to participation; 215 (40%) chose the copper IUD and 327 (60%) chose oral LNG. More than half of all subjects were nulligravid, and planned IUD insertion failed in 42 women (19%) who requested the method. The 1-year follow-up was more than 80% and most (64%) IUD users contacted at 1 year had continued with the method. The primary outcome was analyzed according to "intent-to-treat" and with actual use that took into account that not all of the subjects who desired an IUD were able to obtain one at the initial visit. Among women who chose an IUD, the 1-year cumulative pregnancy rate was 6.5% vs 12.2% in those choosing oral LNG (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.29-0.97). The actual difference in cumulative pregnancy was even more impressive when the IUD group was restricted to only those women who received a device: 5.2% for copper IUD users vs 12.3% for oral LNG users (HR, 0.42; 95% CI, 0.20-0.85). Since this was not a randomized study, the authors also conducted a multivariable logistic regression model controlling for demographic variables and this confirmed that women who chose the IUD for emergency contraception had fewer pregnancies over the next year than those who chose oral LNG (HR, 0.50; 95% CI, 0.26-0.96). Overall, these results provide strong evidence for the use of a copper IUD as a strategy for reducing unintended pregnancy in women who present for emergency contraception.
Commentary
This interesting real-world study evaluates emergency contraception in a novel way by assessing the risk of unintended pregnancy over the subsequent year. The visit for emergency contraception is a teachable moment, just like the visit for a urine pregnancy test. Both of these encounters result from the non-use, improper use, or failure of a contraceptive method. The emergency contraception consult is an event upstream from the pregnancy test, and the existing data suggest that prompt use of emergency contraception after an episode of unprotected intercourse can reduce the risk of pregnancy.1 Levonorgestrel EC is now available over-the-counter, while the slightly more effective ulipristal acetate (Ella®) is prescription only. Unfortunately, the clinical trial results with emergency contraception have not shown substantial population-wise benefits in reducing unintended pregnancy rates.2 Part of this is due to the fact that women don't access emergency contraception in time, and over-the-counter status may help this, but another likely explanation is that women experience repeated episodes of unprotected intercourse. For this reason, it is not surprising that providing ongoing regular contraception is the most important intervention for women presenting for emergency contraception or a pregnancy test evaluation.
The study by Turok et al was not powered to address the question of comparative efficacy of the copper IUD and LNG EC as emergency contraceptive agents, but it is interesting to note that there were four pregnancies resulting from emergency contraception failures in the oral LNG group (1%) and none in the IUD group. These data are consistent with larger studies that support high efficacy with post-coital placement of a copper IUD; no pregnancies were observed in a cohort of more than 1600 Chinese women.3 The data from the Utah group is the first comparator study to support these large descriptive series.
There were two big surprises in this paper. The first is that so many women were willing to accept a copper IUD during the encounter for emergency contraception. It is important to note that none of the subjects came to the clinic requesting an IUD. After receiving information about both methods, about equal numbers of women picked the LNG and the IUD. This suggests that adequate counseling makes a difference in this decision. The disappointing surprise was the very high number of failed IUD placements (19%). The typical rate of failed placement in clinical trials is around 2% so this was very high, and not explained by nulliparity. Better provider training should address this issue. The positive spin is that even with this very high rate of failed placement, the overall chance of pregnancy is lower in women who pick an IUD even if they do not receive the device at the initial consult. These results were robust and not changed after authors adjusted the results for key confounders.
So maybe an office visit for an emergency contraception consult is a good idea after all. The caveat is that this should not delay the initiation of emergency contraception, so family planning clinics and interested office practices need to have same-day availability. Counseling should include the option for placement of a copper IUD.
References
- Glasier AF, et al. Ulipristal acetate versus levonorgestrel for emergency contraception: A randomised non-inferiority trial and meta-analysis. Lancet 2010;375:
555-562.
- Glasier A. Emergency contraception: Clinical outcomes. Contraception 2013;87:309-313.
- Wu S, et al. Copper T380A intrauterine device for emergency contraception: A prospective, multicentre, cohort clinical trial. BJOG 2010;117:1205-1210.
