Emergency contraceptive pills can prevent unwanted pregnancy if taken soon after unprotected sex. Getting a prescription for emergency contraception can be difficult and time-consuming. Giving emergency contraception to women in advance could ensure that women have it on hand in case they need it. We searched for studies comparing women who got emergency contraception in advance to women who got it in standard ways. We examined whether these groups had different rates of pregnancy or sexually transmitted infections. We also studied how often and how quickly both groups used emergency contraception. Finally, we looked at whether advance provision of emergency contraception changed sexual behavior. Studies showed that the chance of pregnancy was similar regardless of whether or not women have emergency contraception on hand before unprotected sex. Women who had emergency contraception in advance were more likely to report use of the medication, and to use it sooner after sex. Having emergency contraception on hand did not change use of other kinds of contraception or change sexual behavior.
閱讀完整摘要
Emergency contraception can prevent pregnancy when taken after unprotected intercourse. Obtaining emergency contraception within the recommended time frame is difficult for many women. Advance provision could circumvent some obstacles to timely use.
目的
To summarize randomized controlled trials evaluating advance provision of emergency contraception to explore effects on pregnancy rates, sexually transmitted infections, and sexual and contraceptive behaviors.
搜尋策略
In November 2009, we searched CENTRAL, EMBASE, POPLINE, MEDLINE via PubMed, and a specialized emergency contraception article database. We also searched reference lists and contacted experts to identify additional published or unpublished trials.
選擇標準
We included randomized controlled trials comparing advance provision and standard access (i.e., counseling which may or may not have included information about emergency contraception, or provision of emergency contraception on request at a clinic or pharmacy).
資料收集與分析
Two reviewers independently abstracted data and assessed study quality. We entered and analyzed data using RevMan 5.0.23.
主要結果
Eleven randomized controlled trials met our criteria for inclusion, representing 7695 patients in the United States, China, India and Sweden. Advance provision did not decrease pregnancy rates (odds ratio (OR) 0.98, 95% confidence interval (CI) 0.76 to 1.25 in studies for which we included twelve-month follow-up data; OR 0.48, 95% CI 0.18 to 1.29 in a study with seven-month follow-up data; OR 0.92, 95% CI 0.70 to 1.20 in studies for which we included six-month follow-up data; OR 0.49, 95% CI 0.09 to 2.74 in a study with three-month follow-up data), despite reported increased use (single use: OR 2.47, 95% CI 1.80 to 3.40; multiple use: OR 4.13, 95% CI 1.77 to 9.63) and faster use (weighted mean difference (WMD) -12.98 hours, 95% CI -16.66 to -9.31 hours). Advance provision did not lead to increased rates of sexually transmitted infections (OR 1.01, 95% CI 0.75 to 1.37), increased frequency of unprotected intercourse, or changes in contraceptive methods. Women who received emergency contraception in advance were equally likely to use condoms as other women.
作者結論
Advance provision of emergency contraception did not reduce pregnancy rates when compared to conventional provision. Results from primary analyses suggest that advance provision does not negatively impact sexual and reproductive health behaviors and outcomes. Women should have easy access to emergency contraception, because it can decrease the chance of pregnancy. However, the interventions tested thus far have not reduced overall pregnancy rates in the populations studied.
