Ectopic pregnancy risk when contraception fails. A review.

OBJECTIVE

To alert clinicians to the risk of ectopic pregnancy when certain contraceptive methods fail by summarizing data from trials reviewed by the U.S. Food and Drug Administration (FDA).

STUDY

DESIGN

The review focuses on 7 contraceptive drug products with an increased risk of ectopic pregnancy when the method fails. Data were extracted from reviews of clinical trials submitted to the FDA to support marketing applications and from the medical literature. Data on 6 other contraceptive drug products and published data for tubal ligations are used for comparison. This review does not include medroxyprogesterone acetate injections because the FDA reviews for this method did not include any pregnancy outcome information.

RESULTS

The results are presented in a table and are compared to postmarketing surveillance reports and published literature, when available. The proportion of ectopic pregnancies among all pregnancies ranged from 1:2 to 1:21 for intrauterine devices, tubal ligations, progestin-only implants and progestin-only oral contraceptives. Although the confidence intervals for the proportions were large in trials with few pregnancies, both postmarketing surveillance reports and published literature support proportions calculated from clinical trial data.

CONCLUSION

Pregnancies in women using progestin-only oral contraceptives, progestin-only implants, intrauterine devices and tubal ligations are more likely to be ectopic than pregnancies in the general population.