Intrauterine devices are commonly used contraceptive method. It is relatively safer and effective. However, in few cases, these devices may be associated with following complications: - cramping pain for few days after insertion - menstrual irregularities - intermenstrual bleeding - menorrhagia - infection - expulsion - perforation of uterus Reference: https://cwhccolorado.com/services/birth-control/iud/iud-complications/index.html Image via: https://www.thebirthcompany.co.uk/iucd-insertion-or-removal.php