Effects of a levonorgestrel intrauterine system versus a copper intrauterine device on menstrual changes and uterine artery Doppler.

OBJECTIVE: To compare the effects of a levonorgestrel-releasing intrauterine system (LNG-IUS) and a copper intrauterine device (Cu-IUD) on menstrual changes and uterine artery Doppler indices.

METHODS: A randomized clinical trial was conducted at Menoufia University Hospital, Egypt, between December 2016 and August 2017. 306 multiparous women desiring intrauterine contraception were randomly assigned to LNG-IUS (n=152) or Cu-IUD (n=154). Uterine artery pulsatility index (PI) and resistant index (RI) were measured before use, and 3 and 6 months after insertion, and associations with abnormal bleeding were evaluated.

RESULTS: Irregular bleeding was initially reported by 31 (74%) of 42 women in the LNG-IUS group, and heavy menstrual bleeding by 53 (67%) of 79 women in the Cu-IUD group. Incidence of abnormal bleeding decreased over the 6-month study period. Uterine artery PI was significantly correlated with abnormal bleeding at a cutoff of 1.35 with area under the curve (AUC) 0.93, sensitivity 88%, and specificity 100%, whereas uterine artery RI was significantly correlated with abnormal bleeding at a cutoff of 0.62 with AUC 0.1, sensitivity 96%, and specificity 100%.

CONCLUSION: LNG-IUS-related abnormal bleeding was associated with changes in uterine artery blood flow that were not evident among Cu-IUD users. Pan African Clinical Trials Registry: PACTR201701001900640.