Comparison of two cohorts of women who expulsed either a copper-intrauterine device or a levonorgestrel-releasing intrauterine system Paula Simonatto, Maria Valeria Bahamondes, Arlete Fernandes, Carolina Silveira and Luis Bahamondes Human Reproduction Unit, Department of Obstetrics and Gynaecology, School of Medical Sciences and the National Institute of Hormones and Women’s Health, University of Campinas (UNICAMP), Campinas, SP, Brazil Abstract Aim: To assess if there is a difference in the characteristics of the women who expelled a copper-intrauterine device (TCu-IUD) or the levonorgestrel-releasing intrauterine system (LNG-IUS) and the frequency of expulsions over different periods of observation. Methods: We retrospectively analyzed 19 697 medical charts of women consulting between January 1980 and December 2013 who requested a TCu-IUD or a LNG-IUS. Results: The medical records of 17 644 Cu-IUD and 2053 LNG-IUS users returning to the clinic for a follow-up visit after insertion of an IUC were reviewed. Of these, 1532 Cu-IUD and 254 LNG-IUS parous users were found to have expelled the IUC for a first time. The mean age at insertion (± standard deviation) was 26.3 ± 6.6 years (range 16–49) for Cu-IUD users and 31.7 ± 7.6 years (range 18–48) for LNG-IUS users (P < 0.001). A total of 263 (13.4%) and 12 (4.3%) of the Cu-IUD and the LNG-IUS users were ≤19 years old, and 49.1% and 54.1% of the expulsions among the Cu-IUD and LNG-IUS users, respectively, were reported in the first six months after place- ment. A regression model showed that the variables significantly associated with an expulsion of either a Cu-IUD or LNG-IUS were age < 25 years, less than two deliveries and using a Cu-IUD. Conclusion: Our findings showed that the characteristics associated with IUC expulsion were age under 25 years, having had less than two deliveries and being users of Cu-IUD. Key words: copper IUD, expulsion, Intrauterine device, levonorgestrel-releasing intrauterine system. Introduction Intrauterine contraceptives (IUCs) include the copper intrauterine device (Cu-IUD) and the levonorgestrel- releasing intrauterine system (LNG-IUS). These contraceptive methods belong to a family of long-acting reversible contraceptives (LARCs), which are among the methods with the highest contraceptive effectiveness. 1–3 The Cu-IUD is the most frequently used reversible contraceptive method worldwide. 4–6 Device-related complications, such as expulsion and uterine perforation, occur to a similar extent with the Cu-IUD and the LNG-IUS. 7 Proper insertion is the key to preventing complications that include bleeding, pain, expulsion and perforation. Approximately one in every 20 women fitted with an IUC expels the device, with expulsion being most common in the first three months after insertion, often during menstruation. 8 Higher rates of IUC expulsion have been reported to be associated with previous expulsion of a device, young age and nulliparity. 9–13 Nevertheless, there is some confusion in the scientific literature regarding the terms nulligravida and nulliparous, which were considered the same, although the first term refers to women who were Received: August 21 2015. Accepted: December 2 2015. Correspondence: Dr Luis Bahamondes, Caixa Postal 6181, 13 084–971 Campinas, SP, Brazil. Email: bahamond@caism.unicamp.br © 2016 Japan Society of Obstetrics and Gynecology 1 doi:10.1111/jog.12939 J. Obstet. Gynaecol. Res. 2016