To evaluate the existing data to estimate the rate of ectopic pregnancy among emergency contraceptive pill treatment failures.
Our initial reference list was generated from a 2008 Cochrane review of emergency contraception. In August 2009, we searched Biosys Previews, the Cochrane Database of Systematic Reviews, Medline, Global Health Database, Health Source: Popline, and Wanfang Data (a Chinese database).
This study included data from 136 studies, which followed a defined population of women treated one time with emergency contraceptive pills (either mifepristone or levonorgestrel) and in which the number and location of pregnancies were ascertained.
Data from each article were abstracted independently by two reviewers. In the studies of mifepristone, 3 of 494 (0.6%) pregnancies were ectopic; in the levonorgestrel studies, 3 of 307 (1%) were ectopic.
The rate of ectopic pregnancy when treatment with emergency contraceptive pills fails does not exceed the rate observed in the general population. Because emergency contraceptive pills are effective in lowering the risk of pregnancy, their use will reduce the chance that an act of intercourse will result in ectopic pregnancy.
The rate of ectopic pregnancy when treatment with emergency contraceptive pills fails does not exceed the rate observed in the general population. SUPPLEMENTAL DIGITAL CONTENT IS AVAILABLE IN THE TEXT.
From Office of Population Research, Princeton University, Wallace Hall, Princeton, New Jersey; Family Health International, Research Triangle Park, North Carolina; The Hull York Medical School, University of Hull, United Kingdom; Shanghai Institute of Planned Parenthood Research, Shanghai, People's Republic of China; Minhang Central Hospital, Shanghai Jiaotong University, Shanghai, People's Republic of China.
Corresponding author: Kelly Cleland, Office of Population Research, Princeton University, 218 Wallace Hall, Princeton, NJ 08544; e-mail firstname.lastname@example.org.
Financial Disclosure James Trussell, Elizabeth Raymond, Linan Cheng, and Kelly Cleland participated in the Data Safety Monitoring Board for two studies of ulipristal acetate conducted by HRA Pharma. Elizabeth Raymond received research grants, consulting fees, or travel expenses from two pharmaceutical companies that sell emergency contraceptive pills. Linan Cheng received research grants, travel expenses, or in-kind support from WHO and CHPFPC.