(PRINCETON, N.J.) -- Intrauterine devices, or IUDs, have been shown to be the best and most reliable emergency contraceptive for women, according to a new study published in the journal Human Reproduction.
An IUD is a T-shaped plastic or copper device that is placed in a woman's uterus to prevent pregnancy. They can be left in the womb between five and 10 years, depending on the brand, but they can also be used as a means of emergency contraceptive. They should be inserted within five days of unprotected sex to properly protect, experts said.
The research showed that IUDs had a failure rate of less than one per 1,000, which was more effective than the morning-after pill, which had a failure rate of 1 to 2 percent. The morning-after pill, or Plan B One-Step, is a pill that should be taken within 72 hours of unprotected sex to avoid pregnancy.
"Emergency insertion of a copper IUD is extremely effective," said James Trussell, professor of public and international affairs at Princeton University and lead author of the study. "We would hope [the findings] would encourage clinicians to talk with women about emergency insertion of a copper IUD during regular visits for later use, should the need arise."
The study analyzed data from 42 studies conducted in six different countries (China, Egypt, Italy, The Netherlands, U.S.A. and the U.K.) between 1979 and 2011. They found that women became pregnant at a rate of 0.09 percent if they used an IUD, as opposed to the 1 to 2 percent pregnancy rate on the morning-after pill.
The research also found that using an IUD for emergency contraception worked just as effectively in women with higher body mass index, while the morning-after pill became less effective at preventing pregnancy in women with higher BMI.
"IUDs are certainly a highly effective form of emergency contraception," said Dr. Ranit Mishori, an assistant professor in the department of family medicine at Georgetown University. "The study appears to confirm it, [but] I think not many women are aware that it is an effective option."
While the device is indeed better at preventing pregnancy, experts say that it is not necessarily the best option for everyone.
"Here are the problems: the IUD has to be inserted and most of the time, ordered," said Dr. Jacques Moritz, director of gynecology at St. Luke's-Roosevelt Hospital in New York. "They are way overpriced in this country. You can't just walk in my office and get an $800 IUD. We have to get it authorized and ordered."
On the other hand, any woman over the age of 17 can buy Plan B One-Step at a pharmacy without a prescription. Females under the age of 17 must have a prescription to obtain the product.
Copyright 2012 ABC News Radio