sweet. i was worried about that one!

That's great news.

Remember who wasn't worried about that one. NARAL. Go see the commentary over at firedoglake.com

I'm completely appalled that NARAL has apparently stepped down as a voice for abortion rights and sound science about reproduction. They are officially off my Christmas list forever.

"this bill also sought to define the age of a fetus by the weeks past fertilization, rather than by the woman's last menstrual period (as every ob/gyn in the country does). So it was not just legislation based on junk science about fetal development. It was also a back-door attack on contraceptives, many of which don't prevent fertilization, only implantation."

I'm confused by what you mean by this. Most doctors and midwives calculate pregnancy by the date of the last menstrual period. This is a very strange way to calculate pregnancy because, since conception occurs mid-cycle, it implies that you're pregnant 2 weeks before you've even had sex. Embryologists, on the other hand, calculate pregnancy based on the date of fertilization. None of them calculate it by the date of implantation, which is about 6 days post-fertilization. Calculating pregnancy by the date of fertilization, rather than the date of the last menstrual period, is much more scientific. It could also be viewed as a more pro-choice way of calculating pregnancy because it extends the time in which women can have an abortion without anaesthetic for the fetus by 2 weeks.

I can definitely understand the political logic of arguing that pregnancy should be calculated by the day of implantation rather than fertilization, but I have trouble with the argument that pregnancy dated by the LMP makes more sense than by the date of fertilization. Can someone help me out here?

Possibly! I work for a pregnancy-related public health program and was just discussing this question with our biostatistician the other day. It's pretty simple -- when calculating pregnancy "from" LMP (date the last menstrual period began), LMP is simply used as a marker for the ovulation that reliably occurs two weeks after the first day of LMP. It is NOT assumed that the woman became pregnant on the first day of her period (that would be pretty dumb). But it does assume that she became pregnant when she ovulated, or pretty soon thereafter, which makes sense. And ovulation reliably occurs, I think it's 10 to 14 days after the first day of the period. The two-week difference is accounted for in the calculation.

It may seem more "scientific" to "base it on the date of conception." But everyone is using different means to guess what that date (of conception) is. The woman rarely knows exactly when she ovulates, or when she conceives. But we can all tell when our period comes! And though the length of the monthly cycle changes, it's the time from ovulation to start of period that varies the most. The time from start of period to ovulation is actually pretty consistent (different hormonal mechanism).

Simple as that! Does this help? Hope so.