Pregnancy despite IUD: adverse effects on pregnancy evolution and fetus

In this retrospective study, we describe cases of pregnancy initiated despite an intrauterine device (IUD), which occurred in our setting in the last 10 years (from January 1992 to December 2001), aiming to point out the effects of IUD in terms of miscarriage or fetal problems.

Histopathologic reports of IUD pregnancies at any gestational age were found by computer search and analyzed. The characteristics of embryo-fetuses and of decidua-placenta were recorded and compared.

Ten IUD pregnancies were found: 3 ended with first-trimester voluntary termination of pregnancy, 2 with second-trimester elective abortions, 2 were miscarried during first trimester (spontaneous abortions) and 3 were carried to term. No relevant abnormalities were found in the development of the embryo-fetuses, except for one case of a newborn with upper lip lesion and a mild deviation of nasal septum. Alterations of the placenta and adnexa were found only in the two miscarriage cases.

The small number of cases found reflects the very low incidence of pregnancies initiated despite an IUD, although an increasing trend has been recorded in the last 5 years, probably concurrently with an increasing immigration flow into our area. Our findings suggest that if the embryo, despite the IUD, can reach a firm attachment during the first weeks of gestation, the pregnancy usually continues to term. It is notable that in this case series a major lip defect occurred in 1 of 10 described cases (10%), suggesting that although pregnancies with IUD are exceptional, fetal abnormalities seem not.