For some reason, the rumor is being passed around again that Governor Jan Brewer signed legislation declaring a woman's pregnancy officially begins two weeks before conception.
Even though the bill in question was actually passed in April, the pregnancy-before-conception myth still gets passed off as fact with regularity -- as recently as yesterday.
The legislation was House Bill 2036, which bans abortions after 20 weeks of pregnancy.
The rumor was that the law would ban abortions after 18 weeks of pregnancy.
Here's an explanation of how that was calculated by the rumor mill at the Huffington Post:
The 18th week bill includes a new definition for when pregnancy begins. A sentence in the bill defines gestational age as "calculated from the first day of the last menstrual period of the pregnant woman," which would move the beginning of a pregnancy up two weeks prior to conception. The bill's passage would give Arizona the earliest cutoff for late-term abortions in the country; most states use 20 weeks as a definition.
That same thought led people to declare that Arizona just made a law stating pregnancy began two weeks before conception.
At the time these rumors started up, we tried to get the bill's sponsor, state Representative Kimberly Yee, to clear this up -- she never got back to us.
However, an actual OB-GYN did address the falsehoods -- Dr. Jen Gunter. You can read her entire retort to one of these false claims by clicking here, but here's the abbreviated version:
No, it doesn't mean that the law prohibits abortion at 18 weeks. It means 20 weeks. Pregnancy has ALWAYS been calculated from the [first] day of the last menstrual period. Always, always, always. When we do an ultrasound, we still use that convention. Perhaps it seems odd to non-obstetrical folks, however, since the last day of the period can be inaccurate (do you use flow? spotting? one spot of blood?), as can date of ejaculation (what if you have sex 3 days in a row?), and date of ovulation (how would you know that?), and the fact that fertilization takes 24-48 hours, the [first] date of the last menstrual period is the only accurate date. Every other state law uses the last menstrual period (as does every obstetrical textbook) because that is the way we calculate gestational age.
The U.S. National Library of Medicine agrees, as does another OB-GYN. We couldn't find a doctor who claimed otherwise.
There are actually controversial things contained in the law, though, as an appeals court has delayed the implementation of the law while it's being challenged, mostly due to the highly suspect claim of "fetal pain" at 20 weeks of pregnancy.
For the purpose of public shaming, though, we'll include a list of a few media outlets we found that blindly believed the pregnancy-before-conception rumor: