An intrauterine device (IUD) is a small piece of flexible plastic shaped like a T that is inserted into the uterus by a doctor or nurse and is effective for five to six years. The non-hormonal ParaGard, also known as a copper T IUD is effective up to 12 years. The most common side effect is mild to moderate pain when first inserted, cramping and heavier periods.
How it works: An IUD uses the hormone progestin to inhibit ovulation while thickening mucus in the cervix to block sperm from fertilizing eggs in the Fallopian tubes. The copper in a non-hormonal copper IUD interferes with the ability of sperm to swim in order to reach an egg.
Cost: Up to $1,000 for an IUD; about $1,600 for ParaGard
Rate of effectiveness: 99 percent