What we've learned about IUDs from the Women's Health Study
Lee, N.C.
American Journal of Gynecologic Health 3(3-S): 27-32
1989
ISSN/ISBN: 0895-3643 PMID: 12284996 Document Number: 377032
A new look at data from the Women's Health Study, done in 1976-1978, focuses on the outcomes of pelvic inflammatory disease (PID) and its determinants, and ectopic pregnancy, in IUD users. The advantage of this data set is that it does not suffer from bias resulting from the bad publicity that IUDs have since received. 657 cases of PID ascertained by discharge diagnosis were compared to 2566 sexually active controls with non-gynecological conditions. The overall data showed that the Dalkon shield conferred a relative risk of 8.3, and the risk was slightly elevated for Progestasert and Copper-7, compared to women using no method of contraception. Broken down by duration of use, most of the risk was limited to the 1st 4 months of use, and the highest risk was in the 1st month, 3.8. Regarding aspects of sexual behavior, the risks were computed for women claiming only one sexual partner. Single and previously married women had about twice the risk of married or cohabiting women. It is likely that this can be explained by a higher proportion of women whose partners were monogamous among married and cohabiting women, than among single or divorced women. The risk of ectopic pregnancy was 0.4 for IUD and traditional method users, and 0.1 for pill users, compared to non-contracepting women. Thus IUDs put women at a slightly higher risk of ectopic pregnancy, but at a low absolute risk, since they lower the overall change of pregnancy.