• The ParaGard IUD contains copper, which prevents sperm's ability to swim and reach the egg.
• The hormone in Mirena IUD thickens cervical mucus, which provides a barrier that prevents sperm from entering the uterus.
• Prevents fertilization of the egg.
• In rare cases when the egg is fertilized, it prevents the egg from attaching to the uterus.
  
   

• Pelvic exam and lab tests are needed.
• Clinician must insert the IUD.
  
   

Must be replaced at a health center at certain intervals:

• Mirena: every 5-7 years
• Paragard: every 10-12 years
  
   

• Doesn't interrupt sex.
• Hassle–free—no pills or patches to remember.
  
  

• May increase risk of tubal infection called PID (Pelvic Inflammatory Disease), which can lead to infertility. Risk is highest in women who have more than one sexual partner.
• Some women have more bleeding or cramping with periods.
• May slip out of place.
• Medical risks: Sometimes causes infection. Rarely can puncture the uterus. Problems can result if user becomes pregnant.
• No protection against STIs/HIV.

Effectiveness: 97% - 99%

More information on IUD.