Effects of the levonorgestrel-releasing intrauterine system versus the copper intrauterine device on uterine artery Doppler indices.

The aims of the study were to evaluate the effects of two types of intrauterine contraceptive device (IUCD) on uterine artery Doppler indices. A multicentre randomised clinical trial was conducted between November 2019 and August 2020. Sixty-six multiparous women aged 18–45 years seeking intrauterine contraception were randomly assigned to receive either the levonorgestrel-releasing intrauterine system (LNG-IUS) or the copper intrauterine device (Cu-IUD). Each group comprised 33 participants. Primary outcome measures were menstrual changes and changes in uterine artery Doppler indices 3 and 6 months after IUCD insertion. Secondary outcomes measures were the relation between Doppler indices and menstrual changes, adverse effects of the assigned contraceptive method and user acceptability of the method. Uterine artery pulsatility index (PI) and resistance index (RI) were significantly higher among women in the LNG-IUS group (p <.001 at 6 months). Whereas the number of women reporting heavy menstrual bleeding decreased at 3 and 6 months in the LNG-IUS group it significantly increased in the Cu-IUD group (p <.001 at 6 months). Multiple logistic regression analysis of participant characteristics and occurrence of heavy menstrual bleeding revealed a significant association with uterine artery RI (p <.01) and the type of IUCD (p <.001). IUCDs are associated with Doppler changes that may be associated with their reported side effects. [ABSTRACT FROM AUTHOR]