Relationship between the use of an intrauterine device and ASC-US

Aims: Cervical cancer is one of the most common gynecological cancers and has poor outcomes. Although it is more easily detected through cervical cancer screening programs, studies on the interpretation of precancerous lesions and their future consequences are among the controversial issues in literature. Atypical squamous cells of undetermined significance (ASC-US) is a category of cervical epithelial cell abnormalities described by the Bethesda system for reporting cervical cytology. It refers to abnormal cytologic changes that suggest the squamous intraepithelial lesion (SIL) but are qualitatively and quantitatively less than those of a definitive SIL diagnosis. Only some studies about intrauterine devices (IUDs), a frequently used family planning method, and causality with ASC-US have been found in the literature. Although it is known that ASC-US may be caused by inflammation, it is not clear whether an IUD can cause it. Our study aimed to evaluate the prevalence of ASC-US in women who used or did not use IUDs and to determine the risk factors associated with IUD use. Methods: Pregnant and lactating women, women with malignancies, hormonal intrauterine devices, vaginal infections, and patients whose cervical screening data were unavailable or diagnosis of inflammation were excluded. Cervical cancer screening results of ASC-US and normal cytologic results were included in the study. Results: At our gynecological oncology reference center, cervical cancer screening (smear + human papillomavirus [HPV] ) was performed on 6452 patients between 2021 and 2022, and the smear result was interpreted as ASC-US in 306 (4.7%) of these patients. In patients without IUDs, the percentage of patients with negative ASC-US cytology was significantly greater (p:0.002) than that in patients with IUDs. The odds ratio was 1.75, as IUD-positive patients had a 1.75-fold risk of having positive ASC-US results. Conclusion: IUDs cause inflammation, which results in ASC-US. In addition to preventing ASC-US formation, this risk can be reduced by 1.75 times by not using an IUD. Even if an IUD is used, the results of colposcopic examinations do not extend beyond the findings of inflammation.