Refocusing On Arizona: Gestational Rates, Facts, and Mythology

Dear Everyone,

Please stop referring to Arizona’s new abortion ban as the “Pregnancy Begins Two Weeks Before Conception Act.”  It’s an ill-informed statement and makes us all look like we don’t know what we’re talking about.  Plus, it focuses on the wrong aspects of the bill.

First of all, from a health care standpoint, pregnancy is nearly always measured from two weeks prior to when implantation (the physiological beginning of pregnancy) actually occurs.  All clinicians – doctors, midwives, the good folks at your local Planned Parenthood–measure pregnancy not from how long a person has actually been pregnant, but from their last menstrual period (LMP), which falls about two weeks prior to implantation. This is partly because we don’t always know exactly when a person actually became pregnant, but mostly because it’s far more accurate to measure a person’s unique gestation rate by her cycle. 

In other words, if I was pregnant and had my last menstrual period on July 23, I would be classified as “six weeks pregnant” even though I’ve probably only been pregnant for about four. This is not unusual, and all clinics that provide abortions measure your pregnancy this way.

Now, let’s instead focus on the real problems with this bill. The ban on abortions after the 20th week LMP (18 weeks gestation, for those of you playing along at home) is an arbitrary marker backed up by the idea that fetuses feel pain after this point (there in fact is no evidence to support this claim).  My own state of North Carolina has had this ban in place for years, as do Alabama, Louisiana, Kansas, Idaho, Indiana, Nebraska, and Oklahoma. The Arizona bill also requires women to have an ultrasound 24 hours to having an abortion, requires clinics that provide abortions to be held to higher standards than most other outpatient surgical facilities, and states that providers must have admitting privileges in local hospitals (again not something that is generally required of practitioners operating in other kinds of outpatient surgical centers). In other words, the Arizona bill is a major attack on abortion access, not just a bill that challenges our understanding of gestational measurement.

So really, instead of calling it the “Pregnancy Begins Two Weeks Before Conception Act,” I’d like to suggest the following alternatives:

  • The “Let’s Use Mythology To Legislate When A Fetus Feels Pain” Act
  • The “Arbitrary Guidelines On Gestational Restrictions For Abortion” Act
  • The “Women Are Incapable Of Making Their Own Decisions” Act
  • The “State-Sanctioned Rape” Act (to borrow from the Virginia bill passed earlier this year)
  • The “Let’s Place So Many Restrictions On Who Can Provide Abortions That No One Can” Act

The above suggestions don’t necessarily roll off the tongue, and to be sure they don’t make for decent soundbites either. But they would keep this whole mess from becoming known as the “Pro-Choice People Don’t Know Anything About Pregnancy” debacle. 

Your Friendly Full-Spectrum Doula,


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  • robin-marty

    fertilization/ovulation is usually 2 weeks after LMP.  Implantation is at least 5 days after, since it has to travel down the fallopean tube and get to the uterus.  drs go by LMP for gestational dating not because they don’t know when fertilization takes place, since many women who want to track can tell based on temperature changes, but because there is no way of knowing exactly how long it takes to implant, since it can be anywhere from 5-10 days.

  • jodi-jacobson

    For some women temperature tracking works, for many others it does not.  I think that saying “many women know” is exaggerated; many women with very regular cycles may know, but others won’t necessarily be able to do so and variations occur frequently, which is why NFP can only be used effectively if you have safe abortion care as a back up.

  • robin-marty

    if you are tracking with the express purpose of temping, etc, most of those women know when they ovulate after the fact, just not before it happens, which is why NFP can work for getting pregnant but utterly sucks as a means of preventing.  Just ask Howie.

  • leftcoaster

    pretending that “pain” is a reason to halt the option. Hello? Can you imagine traveling down a birth canal? Or how about circumcision? Vaccinations?

    Another ridiculous ploy.


  • jodi-jacobson

    that’s the distinction i was trying to make, but you did more clearly.

  • cpcwatcher

    Yup yup yup.  “Fetal pain.”  Psh.  Like I said, there’s no evidence that there’s even pain at this point, but any excuse to limit access, right?

  • cpcwatcher

    Indeed, like I said, *partly* because many women don’t really know actual date of fertilization (let alone implantation!), but also because it’s more likely to reflect a person’s unique gestational cycle.

  • cpcwatcher

    But yes, Robin… you’re correct that LMP is usually 2 weeks prior to *fertilization* and not *implantation*.  Forgive my mistake. :)