Contraception and the risk of ectopic pregnancy: a meta-analysis.

The current knowledge of the association between contraceptive methods and the risk of ectopic pregnancy was evaluated by means of a meta-analysis. Case-control and cohort studies published between 1978 and 1994 in English, French, German and Dutch were retrieved by a search in Medline, a hand-search on recent medical journals and cross-references. Papers reporting on the association between contraceptives and ectopic pregnancy were judged according to predefined entrance criteria concerning selection of control groups, and retractability of raw data enabling the calculation of crude odds ratios. Common Odds Ratios (COR) and 95% confidence intervals were calculated if homogeneity was not rejected. Twelve case-control studies and one cohort study were detected. CORs could be calculated for current and past use of oral contraceptives, past IUCD use and tubal sterilization. All assessed contraceptives protect against ectopic pregnancy. Women becoming pregnant after sterilization or while currently using an IUCD are at an increased risk. The IUCD is the only contraceptive method associated with an increased risk after discontinuation of its use.