Does infection occur with modern intrauterine devices? [editorial]
It is difficult to determine if the IUD increases the risk of pelvic inflammatory disease (PID) because simple clinical features are not consistently predictive and can have low specificity and sensitivity. The C-reactive protein and the erythrocyte sedimentation rate tests help with PID diagnosis, but only a laparoscopy can determine tubal involvement. In 1970, WHO's Cooperative Statistical Programme found 2-year combined PID rates to range from 3.8 to 5.2/100 women with an IUD. Then WHO and various US organizations agreed IUD use did not necessarily cause PID. During the 1970s, however, a large rise in sexually transmitted diseases (STDs), especially chlamydia and gonorrhea, occurred and were associated with PID incidence. Many believed the growing rate of PID was attributable to the increasing use of IUDs. Many studies were biased because of overdiagnosis of PID. A 1990 review of 28 articles revealed that the overall PID rate was 1.49/100 woman years (lower than what many believed earlier). Some researchers used multicountry data on 22, 908 IUD insertions from WHO's data base for IUD studies to determine PID risk in IUD users. This risk was somewhat high during the 1st 20 days postinsertion which may be related to insertion, but PID rates in IUD users corresponded with those from the general population. PID rates did increase with age, however, and they did vary with geographical area. In addition, rates were 62% lower in women whose IUD was inserted after 1980. The PID rate was associated with background risk of STDs. These results and those of other studies suggest that health staff must adequately assess all patients before fitting the IUD and insert it only under strict aseptic conditions. IUDs that release copper and levonorgestrel pose a lower risk of PID than nonmedicated IUDs.