Longer though lighter menstrual and intermenstural bleeding with copper as compared to inert intrauterine devices.

A randomized serial study of uterine blood loss was made of 281 women fitted with one of three intrauterine contraceptive devices (IUCDs): a Lippes loop D, a Dalkon shield or a Copper 7. The increase in the amount of blood loss was greatest with Lippes loop D users and least with Copper 7 users. However, the duration of menstrual and intermenstrual bleeding and of spotting was significantly greater among Copper 7 users than with the two inert devices. Thus the mechanisms whereby IUCDs increase the duration as opposed to the volume of uterine bleeding may be different. Previous users of oral contraceptives were found to have significantly less bleeding before IUCD insertion, but showed a similar pattern of increase of uterine bleeding after IUCD insertion to those who had not used oral contraceptives. For all three IUCDs, the increment in amount and duration of uterine bleeding after insertion decreased between the first and the sixth period, on average by about 15 ml and one to two days. No subsequent improvement was found and after 12 cycles the Copper 7 users had longer but less heavy uterine blood loss than users of the Lippes loop D.