Via ThinkProgress:

A fringe anti-abortion group, Personhood USA, has been startlingly successful at pushing forward legislation across the country that would redefine life as beginning at the moment of fertilization, effectively outlawing contraceptives like birth control pills. Although the medical community has long been in agreement that fertilization does not mark the beginning of a pregnancy — fertilized eggs must first be implanted, and only about half of fertilized eggs actually result in a pregnancy — a growing number of lawmakers are supporting Personhood USA’s efforts to buck medical expertise and legally define life as the moment a sperm meets an egg.

If they succeed in passing such a law — and if such a law survives judicial scrutiny — it could turn common forms of birth control into the legal equivalent of a homicide. While “personhood” laws have always been a transparent attempt to outlaw abortion, the legislation supported by groups like Personhood USA goes much further in trying to assert government control over women’s bodies. These laws would recognize every fertilized egg as an individual and complete human being with full rights, and place millions of women in legal jeopardy. According to 2008 numbers, around 11 million American women use birth control pills and another 2 million use intrauterine devices (IUDs).

Contraceptives like the pill and IUDs not only act to prevent fertilization, but, if fertilization does occur, may prevent that fertilized egg from implanting in a woman’s uterus. Personhood USA considers this tantamount to abortion, and wants to make it a punishable offense for women to control their own fertility. Worse, because the proposed legislation could make any effort to terminate a pregnancy a criminal act, it could also bar doctors from saving the lives of women with ectopic pregnancies, which are never viable and need to be terminated as soon as possible.

Also at risk of prosecution would be the millions of women whose fertilized eggs never begin dividing, never implant, or implant but spontaneously abort. This often happens so early on that the woman never even knows she might have been pregnant.

Keith Mason, the president of Personhood USA, is transparent about his motives, telling NPR, “Certainly women, my wife included, would want to know if the pills they’re taking would kill a unique human individual. And I think there’s a lot of misinformation about that, or lack of information.” Sadly, Mason is not alone. Rachel Maddow reports that this Saturday is the fourth annual Protest the Pill event. Each year the event, put on by another fringe group called American Life League, features slogans like “The pill kills babies,” “The pill kills women,” and “The pill kills marriage.”