Intrauterine adhesions and prior use of a progestin-releasing intrauterine device

Progestin-IUD use was more frequent among IUA cases (29.9%) than polyp (3.4%) or infertile (11.1%) comparison groups. Compared to infertile comparators, any prior progestin-IUD use was independently associated with IUA (aOR 3.12; 95% CI 2.01, 4.85). There was a duration-response pattern: use of 5 years or less was modestly associated with IUA case status (aOR 1.99; 1.09, 3.64), whereas use >5 years conferred more than a seven-fold increase (aOR 7.26; 3.27, 16.11). The association persisted among surgically naive women (aOR 3.98; 2.44, 6.48) and was concentrated in those who were nulliparous, where use beyond five years conferred an approximately twelve-fold increase in odds (aOR 12.74; 5.25,