# New law in Arizona states 'pregnancy begins two weeks before conception' **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 27, 2012, 9:52pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864 "2012-08-27T21:52:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 27, 2012, 9:52pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/1 "2012-08-27T21:52:07Z")
[New law in Arizona states 'pregnancy begins two weeks before conception](http://www.examiner.com/article/new-law-arizona-states-pregnancy-begins-two-weeks-before-conception) > [@](#): > > A new law was signed by Arizona Governor Jan Brewer on Thursday that has abortion advocates up in arms. The new law, titled Women’s Health and Safety Act deems a woman pregnant 2 weeks before conception. > > \ > > Steinberg explained the law by saying, “… It calculates gestational age starting with the first day of the last menstrual period rather than the date of conception.” I’m not familiar with [examiner.com](http://examiner.com). Is it a humour site like The Onion? ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [August 27, 2012, 9:53pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/2 "2012-08-27T21:53:52Z")
Two weeks before conception? How… is that… even _possible?_ ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 27, 2012, 10:03pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/3 "2012-08-27T22:03:53Z")
Just closing the loophole on all those women who were having pre-emptive abortions. ---
**Author:** ![Dr.Woo](https://avatars.discourse-cdn.com/v4/letter/d/7c8e57/32.png) [@Dr.Woo](https://boards.straightdope.com/u/Dr.Woo)\ **Post date:** [August 27, 2012, 10:06pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/4 "2012-08-27T22:06:27Z")
The “date of last menstrual period” is the way doctors often calculate women’s due dates, since most women don’t know when they conceived. That certainly does not explain what these guys were apparently thinking when they phrased the statute that way (if they did - I’m not seeing any real news sources running this story) but hell, it’s probably in response to another one of those mysterious biological functions right wing nutjobs think women possess. Time traveling uteri. I guess. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 27, 2012, 10:08pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/5 "2012-08-27T22:08:02Z")
Okay, for a serious answer, this law is intended to restrict abortions. (Show of hands. Who was surprised by this?) Existing Arizona law only allows abortions in the first twenty weeks of pregnancy. By backdating the start of pregnancies this way, Arizona cuts the window down to eighteen weeks in the real world. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [August 27, 2012, 10:10pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/6 "2012-08-27T22:10:06Z")
I have a feeling the courts will toss this one two weeks before it was signed. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [August 27, 2012, 10:11pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/7 "2012-08-27T22:11:21Z")
> [@Dr.Woo](#): > > The “date of last menstrual period” is the way doctors often calculate women’s due dates, since most women don’t know when they conceived. But wouldn’t [date of last menstrual period] plus 15 days be a more accurate estimate? An egg isn’t released for about 2 weeks after a period commences. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 27, 2012, 10:13pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/8 "2012-08-27T22:13:48Z")
> [@Dr.Woo](#): > > That certainly does not explain what these guys were apparently thinking Don’t blame us guys for this one. The bill was introduced by a female legislator and signed into law by a female governor. ---
**Author:** ![suranyi](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@suranyi](https://boards.straightdope.com/u/suranyi)\ **Post date:** [August 27, 2012, 10:18pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/9 "2012-08-27T22:18:42Z")
> [@Musicat](#): > > But wouldn’t [date of last menstrual period] plus 15 days be a more accurate estimate? An egg isn’t released for about 2 weeks after a period commences. Right, but because most women know their menstrual cycle pretty well, doctors for years have used the date of last menstrual period as the starting date of pregnancy, even though it’s biologicially impossible. I remember when my wife was pregnant the doctor was telling her that even though she was nominally 4 weeks pregnant, it was really only 2 weeks since fertilization. That’s just the way they all do it. So a standard 40 week pregnancy is really only 38 weeks of gestation. Here’s a typical week-by-week pregancy description, confirming this: [http://www.babyzone.com/pregnancy-week-by-week/](http://www.babyzone.com/pregnancy-week-by-week/) ---
**Author:** ![Blackberry](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Blackberry](https://boards.straightdope.com/u/Blackberry)\ **Post date:** [August 27, 2012, 11:35pm UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/10 "2012-08-27T23:35:26Z")
> [@Little\_Nemo](#): > > Existing Arizona law only allows abortions in the first twenty weeks of pregnancy. By backdating the start of pregnancies this way, Arizona cuts the window down to eighteen weeks in the real world. I think that’s how those laws always work anyway. Maybe someone was trying to challenge it to add two weeks to the window of time, but I would imagine that basing it from the first day of the last menstrual period was the intent anyway, since that’s how pregnancies are dated. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 28, 2012, 12:21am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/11 "2012-08-28T00:21:48Z")
> [@Blackberry](#): > > I think that’s how those laws always work anyway. Maybe someone was trying to challenge it to add two weeks to the window of time, but I would imagine that basing it from the first day of the last menstrual period was the intent anyway, since that’s how pregnancies are dated. No, Arizona appears to be going it alone on this one. Eight states have set a twenty-week limit on abortions and, as far as I can tell, every state up to now has set the twenty week period as starting at the date of conception. These laws have been challenged and upheld. But the court decisions appear to say that while a twenty week limit is legal, a shorter limit might not be. (Apparently, no state has enacted a limit of less than twenty weeks.) Arizona legislators must have known that changing the laws to enact an eighteen week limit would not only have started a new round of legal challenges but might also have been overturned. So they reduced the limit by subterfuge instead. They kept the existing twenty-week limit, which has been upheld in court, and just moved the starting date back. ---
**Author:** ![Blackberry](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Blackberry](https://boards.straightdope.com/u/Blackberry)\ **Post date:** [August 28, 2012, 1:43am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/12 "2012-08-28T01:43:26Z")
> [@Little\_Nemo](#): > > No, Arizona appears to be going it alone on this one. Eight states have set a twenty-week limit on abortions and, as far as I can tell, every state up to now has set the twenty week period as starting at the date of conception. Oh, I guess you’re right. I just figured they’d do it that way because the info about abortion I see always says from last menstrual period, but now I see they do add two weeks to it (they say the abortion pill is available until 9 weeks after LMP instead of the 7 weeks I’d heard, which apparently means after conception). Anyway, [this article](http://msmagazine.com/blog/blog/2012/04/10/newsflash-arizona-law-says-life-starts-before-conception/) says the law also says, “women must first look at a state-established anti-choice website that will provide lists of abortion health risks, adoption information and photos of fetal development.” WTF, I wonder how that works. Does someone peer over your shoulder and make sure you’re really looking, and how long do you have to peruse this website? ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [August 28, 2012, 1:56am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/13 "2012-08-28T01:56:20Z")
New pick up line- “Hey babe, I bet you’re already pregnant!” ---
**Author:** ![DummyGladHands](https://avatars.discourse-cdn.com/v4/letter/d/49beb7/32.png) [@DummyGladHands](https://boards.straightdope.com/u/DummyGladHands)\ **Post date:** [August 28, 2012, 1:58am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/14 "2012-08-28T01:58:50Z")
Our favorite line here in the Haboob State is “Pregnancy begins at last call.” ---
**Author:** ![Mama\_Zappa](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@Mama\_Zappa](https://boards.straightdope.com/u/Mama_Zappa)\ **Post date:** [August 28, 2012, 3:17am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/15 "2012-08-28T03:17:03Z")
> [@Musicat](#): > > But wouldn’t [date of last menstrual period] plus 15 days be a more accurate estimate? An egg isn’t released for about 2 weeks after a period commences. It is indeed a more accurate estimation of true fetal age, but the standard (in the US at least) when discussing “weeks pregnant” is to calculate it based on the last menstrual period (LMP). This is because that’s generally easier to pinpoint than actual ovulation dates. So when a doctor says “20 weeks pregnant”, they mean 20 weeks LMP, and they know that it actually means 18 weeks since conception, give or take. Standard pregnancy duration is 40 weeks LMP. If a woman has strong reason to believe conception occurred earlier or later than LMP+14, then they’ll adjust the due date (which is really only important for determining whether the child is premature or has been cooking too long and needs to be induced). Getting back to the OP, I’d have to see how it was phrased in the law, but as wacky as it sounds (and I don’t agree with most of the antiabortion laws out there), the snippet does indeed sound like standard medical practice. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 28, 2012, 3:37am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/16 "2012-08-28T03:37:37Z")
Does that happen two weeks before a legitimate rape also? ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [August 28, 2012, 3:37am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/17 "2012-08-28T03:37:45Z")
> [@Mama\_Zappa](#): > > It is indeed a more accurate estimation of true fetal age, but the standard (in the US at least) when discussing “weeks pregnant” is to calculate it based on the last menstrual period (LMP). This is because that’s generally easier to pinpoint than actual ovulation dates. > > So when a doctor says “20 weeks pregnant”, they mean 20 weeks LMP, and they know that it actually means 18 weeks since conception, give or take. > Standard pregnancy duration is 40 weeks LMP. If a woman has strong reason to believe conception occurred earlier or later than LMP+14, then they’ll adjust the due date (which is really only important for determining whether the child is premature or has been cooking too long and needs to be induced). > > Getting back to the OP, I’d have to see how it was phrased in the law, but as wacky as it sounds (and I don’t agree with most of the antiabortion laws out there), the snippet does indeed sound like standard medical practice. And its about another week from conception to implantation. When I was going through fertility treatments, the RE didn’t want to consider me “pregnant” until we were through the implantation window (apparently, we had no problem conceiving, but a lot of problem with implanting - from what they could tell - which wasn’t, honestly, much) ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [August 28, 2012, 3:40am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/18 "2012-08-28T03:40:14Z")
What I think this really does that is scary is set up the ability for state to limit types of birth control that prevent implantation, should Roe be overturned. The pill does. The IUD does. The pill keeps you from releasing an egg, but if you do, creates an unwelcome environment. The IUD doesn’t even stop the conception. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [August 28, 2012, 4:06am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/19 "2012-08-28T04:06:22Z")
So, here is the _Big Sister_ question: who checks on when her last period was? She might tell whomever that her last period was weeks later than it actually was, do they really expect to be able to gainsay her, and how? ---
**Author:** ![Blackberry](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Blackberry](https://boards.straightdope.com/u/Blackberry)\ **Post date:** [August 28, 2012, 4:13am UTC](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864/20 "2012-08-28T04:13:12Z")
> [@For You](#): > > So, here is the _Big Sister_ question: who checks on when her last period was? She might tell whomever that her last period was weeks later than it actually was, do they really expect to be able to gainsay her, and how? Well, she could lie (or be mistaken) about when conception was too. If there’s any question then they need to date the pregnancy another way, and then just add on two weeks to the answer. It doesn’t mean that the only way they can date a pregnancy is by LMP. [Next page](https://boards.straightdope.com/t/new-law-in-arizona-states-pregnancy-begins-two-weeks-before-conception/632864.md?page=2)