Failed intrauterine device contraception and limb reduction deformities: a case-control study.

Three recent case reports have suggested an association between failed intrauterine device (IUD) contraception and limb reduction deformities in the resulting offspring. To clarify further the purported teratogenic role of the IUD in the etiology of these defects, we conducted a case-control study of 96 mothers who had given birth to infants with limb defects. Interview data about IUD exposure at conception among these mothers were compared with interview data from 2 sets of controls: (1) 915 mothers of infants with other major defects and (2) a subset of the first group consisting of 169 mothers with chromosomally defective infants. No significant increase in the incidence of IUD use was found for cases when compared with either control group. Estimates of the relative risk were 1.28 (95% confidence limits [CL]of 0.29 to 5.67) and 1.78 (95% CL of 0.25 to 12.82) when the first and second groups of controls were used, respectively. These risk figures were not significantly different from 1.0. The evidence accumulated thus far militates against a teratogenic role for the IUD.