CLINICAL ARTICLE Length of the endometrial cavity and intrauterine contraceptive device expulsion M. Valeria Bahamondes ⁎, Ilza Monteiro, Renata Canteiro, Arlete dos Santos Fernandes, Luis Bahamondes Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medical Sciences and National Institute of Hormones and Women's Health, University of Campinas (UNICAMP), Campinas, SP, Brazil abstract article info Article history: Received 21 July 2010 Received in revised form 22 October 2010 Accepted 14 December 2010 Keywords: Endometrial length Expulsion rate Intrauterine contraceptive device Levonorgestrel-releasing intrauterine system Objective: To evaluate the correlation between endometrial cavity length and expulsion rate in acceptors of the TCu380A intrauterine device (IUD) or the levonorgestrel-releasing intrauterine system (LNG-IUS). Methods: The study included 235 nulligravida and parous women who received a TCu380A IUD or LNG-IUS and who were observed for up to 1 year. The length of the uterine cavity was measured by uterine sounding and ultrasonography. Results: The endometrial cavity was shorter than 3.2 cm in 2 LNG-IUS users and at least 3.2 cm long in 87 LNG-IUS users, with expulsions occurring in 0 (0.0%) and 2 (2.3%) of these women, respectively (P N 0.999). Among the TCu380A IUD users, the endometrial cavity was shorter than 3.6 cm in 63 women and at least 3.6 cm long in 83 women, with expulsions occurring in 3 (4.8%) and 5 (6.0%) of these women, respectively (P N 0.999). The mean length of the endometrial cavity—evaluated via ultrasonography— among the 10 women whose devices were expelled was 3.9 ± 0.3 cm, compared with 3.9 ± 0.0 cm in those who retained their devices (P = 0.799). Conclusion: The present results do not support the hypothesis of an association between uterine length and risk of intrauterine contraceptive expulsion. © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. 1. Introduction Intrauterine contraceptives (IUC), including the TCu380A intra- uterine device (IUD) and the levonorgestrel-releasing intrauterine system (LNG-IUS), are highly effective and safe, with few adverse effects. The TCu380A IUD and LNG-IUS devices are both long-acting (up to 20 years and at least 5 years, respectively) [1–4]. However, expulsion is a concern because an unnoticed expulsion can result in an unplanned pregnancy. It is not clear in which women expulsions are most likely to occur. According to Hubacher [5], the expulsion rate of the TCu380A IUD is higher in nulliparous women than in parous women, but other authors [6,7] have reported minimal differences. In a multicenter study conducted by the WHO [8], the TCu380A IUD expulsion rates ranged from 2.5% during the 1st year after insertion to 6.1% during the 8th year; the rates were found to be associated with the experience level of the professional who inserted the device. A higher expulsion rate was reported among women who had a second T-shaped IUD inserted immediately following expulsion of the first one—the expulsion rate 1 year after re-insertion of the device was 31.4% [9]. Similar findings were reported after re-insertion of copper or LNG-IUS devices [10]. One of the hypotheses to explain IUC expulsion involves the length of the uterine cavity. For this reason, many physicians do not recom- mend inserting an IUC in women whose total uterine length (from the external os to the distal end of the fundus) is 6.0 cm or less and in those whose length is more than 9.5 cm [11]. However, Petersen et al. [12] failed to find an association between the length of the uterine cavity, the length of the inserted IUD, and the expulsion rate. The reason for the possible association between the length of the uterine cavity and the risk of IUC expulsion remains unclear. In addition, because the TCu380A IUD is 3.6 cm in length and the LNG-IUS is 3.2 cm, the association between expulsion and endometrial cavity length may be different for these 2 IUC models. The purpose of the present study was to analyze the association between the endometrial cavity/total uterine length and the expulsion rates of the TCu380A IUD and LNG-IUS among nulligravida and parous women. 2. Materials and methods The present study was conducted at the Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil. The Institutional Review Board of the School of Medical Sciences approved the study, and all participants signed an informed consent form prior to admission. The study sample consisted of nulligravida and parous women who were 19–46 years of age and who had participated in a previous study in which the length of the endometrial cavity was measured by uterine sounding and ultrasonography [13]. In that study [13], the endometrial cavity length was evaluated in 570 women, 235 of whom requested insertion of an IUC. Overall, 146 women obtained a TCu380A IUD (Optima, Injeflex, São Paulo, Brazil) and 89 obtained an LNG-IUS International Journal of Gynecology and Obstetrics 113 (2011) 50–53 ⁎ Corresponding author. Human Reproduction Unit, Department of Obstetrics and Gynecology, School of Medical Sciences and National Institute of Hormones and Women's Health, University of Campinas (UNICAMP), Caixa Postal 6181, 13084-971, Campinas, SP, Brazil. Tel.: +55 19 3289 2856; fax: +55 19 3289 2440. E-mail address: vbahamondes@cemicamp.org.br (M.V. Bahamondes). 0020-7292/$ – see front matter © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijgo.2010.10.013 Contents lists available at ScienceDirect International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo