(Slate) – In the 1970s, a dangerous device hit the market. Today, millions of women use IUDs safely—but to many, they remain as mysterious as ever.

There are decades’ worth of rigorous studies that validate the safety and efficacy of IUDs. Their message is quite clear: Adverse events happen, but severe ones are rare. Pregnancy with an IUD in place happens, but again, it is very rare. The IUD is, these studies show, a stellar form of birth control.

And yet: Many women regard the IUD as a sort of poltergeist, liable to mess with everything from their temper to their appearance. (Read More)