How do IUD’s work?

IUDs affect the way sperm move and survive in the uterus, preventing these cells from reaching and fertilising the ovum (egg). IUDs can also cause changes to the lining of the uterus to stop a fertilised ovum from developing.

The hormonal IUD can thicken the mucus made by the cervix (entrance to the womb), preventing sperm from getting through, and can also affect ovulation by altering the hormones that cause an ovum to be released each month.