IUDs and other long-term contraception methods are better at preventing pregnancy than pills, says a new study.

The study group included nearly 7,500 women and teenagers. They were then given information about the advantages and disadvantages of IUDs, implant, birth control pills, patch, ring and contraceptive injection and were asked to choose a method that they like. The participants were allowed to change methods as frequently as they wanted.

The researchers found that 334 women got pregnant over the three year study period. Women on pills were 20 times more likely to get pregnant than women who chose other contraceptive methods.

"When patients talk to their doctors about birth control, their first concern is always efficacy. So why don’t we offer the most effective methods first? And if they choose not to have the most effective method [IUDs, implants], then move to second tier methods like the birth control pill, patch and ring," said Dr. Jeffery Peipert, senior author of the study. There are many published studies that describe the efficiency of the contraceptive methods while there are others that study the failures of these devices in preventing pregnancies. Most experts agree that the method fails due to discontinuation or not following the advice on the use of the method.

According to CDC report on use of contraception in United States in years 1982-2008, 99% of women who ever had an intercourse used one of the contraceptive methods. The report suggests that most pregnancies are cause by inconsistent or incorrect use and not by the method itself.

In 2006-2008, close to 10 million women were using oral pills.

The CDC report says that 10% of the pill users (1.4 million) stopped taking the pill because they got pregnant.

FDA recommends that women, who are over age 35 and smoke, should not take any type of combination birth pill (including those containing drospirenone), due to increased risk of serious cardiovascular events.

Previous studies have suggested that women place more faith on pills than they should.

"The pill is 99 percent effective as long as you remember to take it every day, which to me, it's ridiculous to talk about a 'perfect' user rate because that's not real life. In real life, there is user error. The longer-acting methods remove that error.  Once they're in place, you can forget about them," Peipert told FoxNews.

Experts say that many women choose pills over other methods because of the cost of an IUD can go to almost $800. However, IUDs give better protection and last for years.

The present study is published in New England Journal of Medicine.