Major Finding: Women with EC on hand were no less likely to become pregnant than those who had “standard access.” Odds ratios for becoming pregnant ranged from 0.48 to 0.98 for studies with follow-up of 3-12 months.
Data Source: A meta-analysis of 11 randomized controlled trials involving 7,695 women from the United States, China, India, and Sweden.
Disclosures: Two of the Cochrane Review authors were also investigators involved in studies that were included in the review. Ibis Reproductive Health provided support for this study.
Advance provision of emergency contraception is associated with earlier use and increased overall use of EC following unprotected sex, but it does not reduce pregnancy rates, according to the findings of an updated Cochrane Review.
Eleven randomized controlled trials involving 7,695 women from the United States, China, India, and Sweden were included in the new review, which is an updated version of a review completed in 2007 with similar findings.
Women in the 11 trials who had emergency contraception (EC) on hand were no less likely to become pregnant than those who had “standard access,” such as counseling and/or access on request, lead researcher Chelsea Polis of Johns Hopkins University, Baltimore, and her colleagues reported online in the Cochrane Database for Systematic Reviews. Odds ratios ranged from 0.48 to 0.98 for studies with follow-up ranging from 3 months to 12 months, respectively.
Compared with those who had standard access, the women with advance access did use EC more often (odds ratio, 2.47 for single use, 4.13 for multiple use); and they used it earlier (weighted mean average of 12.98 hours earlier). They also were no more likely to contract a sexually transmitted infection (OR, 1.01).
Condom use was the same among those with and without advance access, the investigators found (Cochrane Database Syst. Rev. 2010 [doi:10.1002/14651858.CD005497
Providing EC in advance of need is a common strategy for ensuring that women have access to EC when they need it, but despite earlier optimistic projections of the potential public health impact of improved access, the findings of this review suggest this approach does not reduce unintended pregnancy, Ms. Polis and her associates reported.
Part of the problem is that some women do not use EC even when it is available. Nonuse varied widely across the studies included in the review, and research suggests that several factors contribute to the decision to not use EC, including unperceived pregnancy risk, concerns about side effects, and inconvenience, the investigators noted.
Nonetheless, the findings should not preclude women from being provided with advance access to EC, particularly since obtaining EC when needed can be difficult and time consuming, and because the review suggests that advance access does not negatively impact sexual and reproductive health behaviors and outcomes, they said.
“Women should be given information about and easy access to emergency contraception because individual women can decrease their chances of pregnancy by using this method,” Ms. Polis and her associates wrote. Future research should focus on the reasons behind failure to use EC when needed and available.
Emergency contraception methods included in this review were combined estrogen-progestin, levonorgestrel alone, and mifepristone.