15th April 2024

Intrauterine devices and intrauterine system

Intrauterine devices (IUDs) are inserted into the endometrium with active forms containing copper-inhibiting implantation enzymes. These are typically replaced every 5 years and can be used as emergency contraception. As it does not use hormones, there are no hormonal side effects.

The intrauterine system (IUS) is inserted into the uterine cavity and contains progestogen, which prevents endometrial proliferation, suppresses ovulation and thickens cervical mucus. With both the IUD and IUS, there is an increased risk of pelvic infections and ectopic pregnancy.