Upper Genital Tract Infections Following IUD Insertion

Pathophysiologic Mechanism

The CDC guidelines explicitly identify uterine instrumentation, specifically IUD insertion, as a factor that facilitates upward spread of vaginal and cervical bacteria to the endometrium and fallopian tubes, which is the fundamental pathogenesis of PID 1, 2, 3
PID results from direct canalicular spread of organisms from the endocervix to the endometrial and fallopian tube mucosa 1, 2
IUD insertion mechanically disrupts the cervical barrier, allowing bacteria present in the lower genital tract to ascend 1, 2

When a woman with an IUD develops upper genital tract infection, this is diagnosed and managed as PID, regardless of the insertion being the precipitating event 4, 5, 6
The CDC Medical Eligibility Criteria assigns Category 4 for IUD initiation during current PID, and Category 2 for continuation, meaning the IUD usually does not need to be removed if the woman wishes to continue using it 4, 5, 6
Treatment consists of appropriate antibiotics for PID; clinical course does not differ whether the IUD is removed or left in place 4, 5, 6

Upper genital tract infections following IUD insertion involve the same polymicrobial flora as other PID cases, including Chlamydia trachomatis and Neisseria gonorrhoeae 1, 3
Anaerobes, such as Bacteroides, Peptostreptococcus, and Peptococcus species, are also involved 1, 3
Facultative bacteria, including Gardnerella vaginalis, Streptococcus species, E. coli, and Haemophilus influenzae, are also present 1, 3

The absolute risk of PID following IUD insertion is low in women without pre-existing STIs, but significantly elevated in women with cervical infection at the time of insertion 5
Women with current purulent cervicitis, chlamydial infection, or gonorrhea should not have an IUD inserted until infection is treated 4, 5, 6