Positional factors of the uterus play a contributing part in IUD failure.

This study is based on a uniform material of 3 500 copper IUD insertions at the Family Planning Unit of Turku Health Center, including 72 cases resulting in pregnancy. Among the pregnant subjects there were significantly more women with a retroverted flexed or mid-positioned uterus than in the control material. Repeat IUD pregnancies were rather common. These observations should be taken into account in practice, especially regarding great care with the insertion technique and a close follow-up of these women. The predisposing factors and the outcome of accidental pregnancies are discussed.