US researchers reckon that intrauterine devices (IUDs) are more effective in preventing an unplanned pregnancy than emergency birth control pills.

A team of experts at Princeton looked into 42 previous studies conducted over the last three and half decades and concluded that with a failure rate of 0.09%, intrauterine devices may be the most effective emergency contraceptive option around.

Data from 7,034 cases revealed that the IUD can ensure a higher percentage of safety and reliability than the emergency contraceptive pill or plan-B. On average, plan-B enjoys an 80% success rate, meaning that only 20 out of 100 women taking a pill within 72-120 hours of unprotected sexual intercourse become pregnant.

However, surveys reveal that the use of IUDs is still woefully less compared to that of other birth control measures. Only 10 out of 100 sexually active women in the UK rely on a mechanical contraception to dodge an unwanted pregnancy.

The researchers said cost of the implant and usability hazards could be two main reasons a majority of sexually active women prefer to resort to pills. Anybody looking for a protection against pregnancy can simply get a pack of tablets either from an online clinic or local pharmacy, whereas insertion of an IUD can only be done with the assistance of a healthcare professional.

"There are a lot of barriers to the use of IUDs", lead study author Kelly Cleland said, adding, "Providers don't offer them, insurance doesn't cover them, they can be hard to get. So the emergency contraceptive pill is an excellent option."

Nevertheless, the study authors did not fail to point out that the birth control implant is a one-time procedure, capable of providing protection against pregnancy for a decade.