Production of fibrinolytic enzymes by macrophages on intrauterine contraceptive devices.

Intrauterine contraceptive devices (IUCDs) were removed from 44 patients with a variety of clinical conditions, and incubated in culture media. Following incubation for up to 96 hours the total numbers of macrophages on each device were counted. The Lippes loop and Saf-T- Coil had higher counts than the Copper 7. The counts on all devices were higher at mid-cycle and during menstruation and significantly higher in patients with menorrhagia and intermenstrual bleeding (P less than 0.0005). Samples of culture media were taken on a number of occasions for up to 96 hours for fibrinolytic studies, and fibrinolytic activity increased with time in 10 of 16 cases where fibrinolytic activity was detected. There was a weak positive correlation between the number of cells on each of the 10 devices which produced a rise in fibrinolytic activity and the highest level of activity produced by each of the devices (r = +0.59; P less than 0.05). Plasminogen activator activity was maximum early in the incubation period, while plasmin-like activity predominated in later samples. The possible role of macrophages in IUCDs in causing menorrhagia is discussed.