Editor’s Note: This article was amended at 2:03 pm EDT on Wednesday, April 4th, 2012 to address an error in the original article, which incorrectly stated that Arizona’s 20-week abortion ban was the only one among several states considering or passing such bans to use “last menstrual period” for dating gestational age, and to clarify the intention of the original piece. Edits are visible in the article itself.

The past few months, we’ve seen the nation wake up to many anti-choice assaults on women’s basic right to control their fertility, especially with regards to imposing forced ultrasounds and numerous attacks on access to basic contraception. But one of the other favorite anti-choice approaches to maximizing the pain and suffering of women as punishment for sex has largely gone unnoticed by many outside of the pro-choice activist community: bans on abortions after 20 weeks. It’s understandable that it’s hard to whip people up about this particular situation. After all, abortions after 20 weeks are relatively rare. Only 1.5 percent of abortions occur after the 20th week, and the vast majority of those that do occur are done for medical reasons, or because legal and financial obstacles–like those put in place by lawmakers–caused a delay in getting an early abortion. While, if they knew their personal stories, most people would certainly sympathize with women in need of post-20-week abortions, a certain amount of reproductive rights fatigue is setting in. There’s only so many hours in the day, and anti-choicers know if they just keep throwing restrictions on access at us, some will slip through the cracks.

But, as exhausting as it is, we need to pay attention to and resist post-20 week bans on abortion. That’s because they are cruel on the surface, but also because legislators are using 20-week bans to smuggle in other items of more importance to them than simply making it harder for a slim minority of women seeking abortions to get them. The most obvious thing they’re trying to do is set anti-science precedent [create legal precedents for medical procedures.] Since these bans are based on the false, unscientific claim that fetuses at 20-weeks can feel pain, if they’re allowed to stand, they open the door for more laws based on straight-up lies to be passed. These laws are also being used to challenge the requirement set out in Roe v Wade that a woman’s health and life should trump that of the misogynist desire to keep her pregnant at all costs.

Legislators have had so much success smuggling in ulterior motives with 20-week bans that they’re now looking for ways to expand the amount of hard right anti-choice nonsense they can attach to those bills. The most A recent—and extreme—example is Arizona. There, lawmakers are writing a 20-week abortion ban that, [like those in other states] starts counting off seeks to legislate pregnancy as beginning at the first day of a woman’s period. Yes, they’re arguing that you’re “pregnant” while you’re actually getting your period. In fact, as Kate Sheppard at Mother Jones explains, they’re really trying to steal as many weeks as possible away from women seeking abortion:

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Most women ovulate about 14 or 15 days after their period starts, and women can usually get pregnant from sexual intercourse that occured anywhere between five days before ovulation and a day after it. Arizona’s law would start the clock at a woman’s last period—which means, in practice, that the law prohibits abortion later than 18 weeks after a woman actually becomes pregnant.

That’s bad in and of itself, but taking a step back and looking at the big picture makes this law look even more sinister.

[While it is true that medical professionals dealing with both wanted and unwanted pregnancies use the date of last menstrual period to gauge gestational age, this is a medical tool for assessing a pregnancy; it becomes a dangerous precedent in the hands of anti-choice legislators.]

Medically speaking, pregnancy starts when a fertilized egg implants in the uterine lining. Anti-choicers have attempted to define it earlier shift the goalposts of pregnancy with their failed attempts to pass “personhood” laws conferring the full rights of a living, breathing person on a fertilized egg. that would define not just pregnancy, but “personhood” as beginning at conception. Arizona and other states with 20-week bans are trying to argue that you’re pregnant a couple of weeks before you even had the sex that resulted in your pregnancy.

Think about the implications down the road. If a woman is “pregnant” two weeks before she becomes pregnant, than any fertile woman—including those currently menstruating!—should really be considered pregnant. After all, we don’t know the future. We don’t know that any non-pregnant woman couldn’t be pregnant two weeks from now, making her retroactively pregnant now. Considering that it’s anti-choice nuts we’re talking about, it’s safe to assume that they’d simply prefer a situation where all women of reproductive age are considered to be pregnant, on the grounds that they could be two weeks from now. Better safe than sorry, especially if that mentality means you get to exert maximum control over the bodies of women of reproductive age.

Between personhood bills and the assault on access to contraception, it’s becoming increasingly clear that anti-choicers aren’t satisfied with simply trying to control the already-pregnant. Finding ways to define the not-pregnant as pregnant is a means of laying the groundwork for exerting this control. Imagine if Roe is overturned and states go into a true frenzy of stripping every imaginable right away from pregnant women. It wouldn’t be limited to stripping the right to abortion, but also to any kind of behavior deemed “abortive,” including holding certain kinds of jobs, eating certain foods, or taking certain medications. With this bill, then, you could not only restrict the rights of those who are actually pregnant, but extend the restrictions to all women of reproductive age on the grounds that they “could be pregnant in two weeks, i.e. in perpetuity” and would therefore be considered the same thing as being pregnant.

Already in some states, they’re looking for ways to prosecute women who have stillbirths if they did something the prosecutor believes may have had an impact on the pregnancy, such as drug use. With the hoped-for overturn of Roe, we can expect these efforts to intensify, with prosecutions of miscarriages. Now with this Arizona bill, if a woman is deemed pregnant two weeks before she actually is, prosecutors could even have a chance to look at your choices when you weren’t even pregnant—before you even had the sex that made you pregnant—and blame those choices for bad outcomes. They’re creating, brick by brick, the legal basis on which to prosecute a woman who drinks some alcohol, becomes pregnant two weeks later, and miscarries, even though she didn’t drink while pregnant. And you best believe that when feminists protest this, they’ll just paint it as if we’re more interested in protecting drunken sluts than “babies.”

If you can [legally] be “pregnant” without being pregnant, that also creates legal complications around simple menstruation. After all, menstruation is usually seen as the opposite of being pregnant; women use menstruation to mark that they aren’t pregnant. But under this bill, you could both be menstruating and “pregnant” by law. Should Roe be overturned and the state start looking to prosecute women for miscarriages they deem inappropriately prevented, what about women who are just getting their period? They’re “pregnant” under the pregnant-prior-to-conception framework, aren’t they? Are they miscarrying in the eyes of the law or are they just continuing their theoretical pregnancy? These kinds of ambiguities are exactly the sort of thing zealous misogynist law enforcement will be looking to exploit.