Comparative multicentre trial of three IUDs inserted immediately following delivery of the placenta

A multinational comparative trial of three IUDs (Copper 7, Lippes loop size D and the Postpartum T) randomly inserted immediately following delivery of the placenta was conducted in six centres. A total of 841 women entered the study. As the predetermined termination indices for expulsions were exceeded at six months the trial was prematurely closed. An excess of expulsions during the first 48 hours following insertion was observed for the Lippes loop compared to the other devices. At six months the expulsion rate for the Lippes loop was significantly higher than that for the Copper 7. In addition, the discontinuation rate for the Lippes loop at 12 months was significantly higher than that for the Copper 7. There were no significant differences in either the expulsion rates or the discontinuation rate at six or twelve months between the postpartum T and the other devices. At 12 months the pregnancy rates with all three devices was high; there were no ectopic pregnancies. Considerable between-centre differences were observed, particularly for expulsion rates. Possible reasons for this are discussed and future research lines are suggested.