Experience with the copper-7 and copper-T intrauterine devices at Siriraj hospital in Bangkok, Thailand

Abstract

A report of 2 studies focusing on the 2 year performance of Copper-7 (Cu-7) and Copper-T (Cu-T) IUDs is presented with particular reference to the characteristics of the users. 198 women had the Cu-7 IUD inserted and 200 women had the Cu-T inserted while menstruating or immediately after menstruation. In both devices, the copper wire had the same surface area. Of the sociodemographic and reproductive characteristics of the study groups, only the age and parity distributions were significantly different. The median age for the Cu-7 users was 26.8 years compared to 31.5 years for the Cu-T group. A median of 2.2 live births for the Cu-7 group is lower than for the Cu-T users (3.2 live births). Performance of the 2 devices did not differ significantly, over the study period. The net cumulative continuation rates were 68.6/100 Cu-7 users and 78.2/100 Cu-T users. At the end of 1 year, the gross cumulative pregnancy rate with the device in place was the same for both groups, .6/100 women. After 2 years, 2 additional Cu-7 users became pregnant, and the gross cumulative pregnancy rate was 2.3/100 women; the Cu-T rate remained the same. The pregnant women in the Cu-7 group were under 30 years of age. The gross cumulative expulsion rates at the end of 1 year were 5.0/100 Cu-7 users and 1.8/100 Cu-T users; after 2 years, the rates were 5.7/100 Cu-7 users and 2.5/100 Cu-T users. The majority in both groups were under 30 years old. For both groups, discontinuation of the IUDs because of pain was more frequent than for bleeding. The gross cumulative discontinuation rates of removals for bleeding/pain were 4.1/100 Cu-7 users and 2.4/100 Cu-T users at 1 year and 7.1/100 Cu-7 users and 5.7/100 Cu-T users after 2 years. 81.3% of these discontinuations occurred in women under 30 years old for the Cu-7 group compared to only 45.5% of the women discontinuing the Cu-Ts. The age-parity effect is difficult to specify due to the infrequency of events. However, younger less parous women, which was a higher proportion of the Cu-7 group, did have a higher incidence of expulsions and Cu-7 removals for pain/bleeding. The Cu-T group had a much higher proportion of women with previous IUD experience. The results suggest that the Cu-7 is as effective as the Cu-T device in minimizing the incidence of pregnancy, expulsion, and bleeding/pain removal.