Birth Control

IUDs

The Paragard IUD can remain in place for 10 years, while the Progestasert IUD must be replaced every year. It's not entirely clear how IUDs prevent pregnancy. They seem to prevent sperm and eggs from meeting by either immobilizing the sperm on their way to the fallopian tubes or changing the uterine lining so the fertilized egg cannot implant in it.

IUDs have one of the lowest failure rates of any contraceptive method. It is intended for the population of women in mutually monogamous, stable relationships because these women have the lowest risk of infection. For these women, the IUD is a very safe and very effective method of contraception. The overall failure rate is 0.6% for the Copper T and 1.5% for the Progesterone T.

There have been questions raised about the safety of IUDs and, in particular, the Dalkon Shield. The Dalkon Shield IUD was taken off the market because it was associated with a high incidence of pelvic infections and infertility, and some deaths.

Today, serious complications from IUDs are rare, although IUD users may be at increased risk of developing pelvic inflammatory disease. Other side effects can include perforation of the uterus, abnormal bleeding, and cramps. Complications occur most often during and immediately after insertion.