Exposure to sexually transmitted pathogens is the more important determinant of PID risk than is wearing an IUD. In the Women’s Health Study, women who were married or cohabiting and who said they had only one sexual partner in the past 6 months had no increase in PID (75). In contrast, previously married or single women had marginal increase in risk, even though they had only one partner in the previous 6 months (77). The only pelvic infection that was unequivocally related to IUD use is actinomycosis (78). It appears that PID with actinomycosis was reported only in women wearing an IUD. Rates of colonization with actinomycosis increase with duration of use for plastic devices but appear to be much less for copper-releasing IUDs. Actinomyces may be found in cervical cytology of up to 7% of women with an IUD. Because of the low positive predictive value and a lack of sensitivity and specificity of cervical cytology to diagnose this organism, antibiotic treatment and IUD removal should be reserved for symptomatic women (79).
When PID is suspected in a woman wearing an IUD, appropriate cultures should be obtained, and antibiotic therapy should be administered. Removal of the IUD is not necessary unless symptoms do not improve after 72 hours of treatment (80). Pelvic abscess, if suspected, should be ruled out by ultrasound examination.
Ectopic Pregnancy All contraceptive methods protect against ectopic pregnancy by preventing pregnancy. But when the method fails and pregnancy occurs, risk of ectopic is affected by the method of contraception. IUDs and tubal sterilization increase the probability of the pregnancy being ectopic when pregnancy occurs, but the rate of any pregnancy is so low that women using either of these methods have much lower rates of ectopic pregnancy than women not using contraception (81). Risk of any pregnancy with a levonorgestrel IUD is between 0.1 and 0.2 per 100 woman-years. The rate of an ectopic in wearers of this device is reported as 0.02 per 100 woman-years (82). In a large study of the copper T380A, the first-year pregnancy rate was 0.5 per 100 woman-years, and the rate of ectopic was 0.1 per 100 woman-years (83). Ectopic is a very rare event with either IUD, but should a woman wearing one present with pelvic pain and a positive β-HCG, an ectopic must be ruled out. Increased risk of ectopic among past users of older IUDs was reported. The copper T380A and the levonorgestrel T were not included (81).
Fertility Tubal factor infertility is not increased among nulligravid women who used copper IUDs, but exposure to sexually transmitted pathogens such as C. trachomatis does increase risk (84). The Oxford study found that women gave birth just as promptly after IUD removal as they did after discontinuing use of the diaphragm (85).
Expulsion and Perforation The rate of expulsion with the copper T380A is reported to be 2.5 per 100 woman-years in the first year, and cumulates to 8 per 100 woman-years after 8 years (83). Expulsion rates with the levonorgestrel T were reported at 4.2% in years 1 and 2, 1.3% in years 3 through 5, and 0% in years 6 and 7 (86). The risk of uterine perforation associated with insertion is dependent on the inserter. The risk in experienced hands is on the order of 1 per 1,000 insertions or less (87). There are no studies specifically addressing perforation in nulliparous as compared to parous women (88).