dr. ellen whitaker says the older iuds were linked to a higher risk of pelvic infection that often causedations, including infertility and even death. but now the devices have been redesigned and newer models like the popular brand merina has so far proven to be safe and have fewer side effects compared to other forms of contraception. >> it is pretty minimal. therefore, it does not have those effects like some women have on thing like birth control pills. >> iuds are implanted directly into the uterus. the device is copper or hormones similar to what is found in birth control pills. the device can last anywhere from three to ten years and can be removed by your doctor at any time. >> one of the reasons why they are so effective is because they get rid of that human error part. they forget to take pills or get their refills. >> doctors say that there are still some risks with that's newer iuds, although they are rare. they include infection and even puncture of the uterus. also, doctors say, iuds can be more expensive than birth control pills because of the cost of implanting the device.