Intrauterine devices and ectopic pregnancy

doi:10.1136/bmj.b3864

Published 22 September 2009, doi:10.1136/bmj.b3864
Cite this as: BMJ 2009;339:b3864

Letters

Contraception for women

Intrauterine devices and ectopic pregnancy

The first 150 words of the full text of this article appear below.

The relation between intrauterine devices and ectopic pregnancycontinues to cause confusion, just as it did when my colleaguesand I reported the relevant findings in our cohort study in1974.¹ ²

Amy and Tripathi state that " a meta-analysis of case-controlstudies showed that ectopic pregnancy is not more common inwomen who conceive with an intrauterine device in place."¹ Themeaning of this statement is not clear to me, but the clinicallyimportant fact is that if a woman with an intrauterine devicein situ presents with an accidental pregnancy she is far morelikely than a woman who has become pregnant under other circumstancesto have an ectopic pregnancy. Indeed, the review cited by Amyand Tripathi gives the increase in risk as 10.6-fold.³

The reason for this is that intrauterine devices are far lesseffective in preventing ectopic pregnancies than intrauterinepregnancies. Failure to appreciate this fact . . . [Full text of this article]

Martin P Vessey, emeritus professor of public health¹

¹ Unit of Health Care Epidemiology, Rosemary Rue Building, Old Road Campus, Oxford University, Oxford OX3 7LF

martin.vessey@dphpc.ox.ac.uk