Effect of vaginal administration of misoprostol before intrauterine contraceptive insertion following previous insertion failure: a double blind RCT.

STUDY QUESTION Is pretreatment with misoprostol useful in insertion of intrauterine contraceptives (IUCs) after insertion failure at the first attempt? SUMMARY ANSWER Pretreatment with intravaginal administration of 200 mcg of misoprostol after IUC insertion failure 10 and 4 h before the second attempt of IUC placement was significantly better than placebo at facilitating the insertion of an IUC. WHAT IS KNOWN ALREADY One of the reasons for low use of IUCs is the concept that insertion is difficult. Misoprostol was used in several randomized clinical trials (RCT) before IUC insertion to facilitate the insertion. In general, the results showed no significant differences when compared with placebo. However, most previous studies have been carried out among unselected women whereas the present study is among women with previous insertion failure. STUDY DESIGN, SIZE, DURATION This was a double blind RCT conducted between February 2013 and October 2014. Participants were 104 women who requested an insertion of an IUC and the insertion failed at the first attempt. After insertion failure, the women received a sealed envelope with misoprostol or placebo. The randomization system (1: 1) in one block size was computer-generated. PARTICIPANTS/MATERIALS, SETTING, METHODS The study was conducted at a tertiary care centre. The women were instructed to insert vaginally one tablet of misoprostol 200 µg (Prostokos, Hebron, Cariacica, PE, Brazil) or placebo 10 and 4 h before the woman returned to the clinic for a new insertion attempt. The outcomes were successful IUC insertion and the use of a cervical dilator immediately prior to the insertion procedure. MAIN RESULTS AND THE ROLE OF CHANCE A total of 2639 women requested the insertion of an IUC during the study period. The IUC was inserted at the first attempt in 2535 women (96%) and 104 women in whom we were unable to insert the device were eligible to participate in the RCT. Four women declined and 100 women were randomized (55 for the misoprostol group and 45 for the placebo group). From the 100 participating women, the levonorgestrel-releasing intrauterine system (LNG-IUS) was chosen by 55 and 37 women and the TCu380A intrauterine device (Cu-IUD) was chosen by none and 8 women in the misoprostol and placebo group, respectively. Seven and three women allocated to misoprostol and placebo, respectively, never returned to the clinic after randomization. We placed the IUC in 42 (87.5%) out of the 48 women and in 26 (61.9%) out of the 42 women randomized to misoprostol and placebo, respectively (P = 0.0066). Regarding the Evaluable Population the relative risk (RR) of successful insertions was 1.41 (95% confidence interval (CI) for absolute difference (8.2, 43.0), P = 0.0066); in the Intent-to-Treat Population the RR (95% CI) was 1.32 (0.3, 36.9). Multiple regression analysis showed that the significant variables associated with the insertion failure were the number of Caesarean section ≥1 (P = 0.020) and the use of placebo (P = 0.026). Dilators were used in 21 (43.7%) out of the 48 and 21 (50%) out of the 42 women randomized to misoprostol and placebo, respectively (P = 0.804). LIMITATIONS, REASONS FOR CAUTION The limitations were that the majority of the women chose the LNG-IUS, and consequently the data for the Cu-IUD were limited, and there was a small number of nulligravidas. WIDER IMPLICATIONS OF THE FINDINGS The results show that IUC insertion difficulties and failures are not common. Pretreatment with intravaginal misoprostol facilitated IUC insertion after failure of insertion at the first attempt, and insertion failure was associated with number of Caesarean sections. STUDY FUNDING/COMPETING INTERESTS This study received partial financial support from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), grant # 2012/10085-0, and from the National Research Council (CNPq), grant #573747/2008-3. All the TCu380A IUDs were donated by Injeflex, São Paulo, Brazil, and all the LNG-IUS were donated by the International Contraceptive Access Foundation (ICA), Turku, Finland. Both donations were provided in the form of unrestricted grants. The authors declare that there are no conflicts of interest associated with this study. TRIAL REGISTRATION NUMBER ClinicalTrial.gov NCT01754649.