I'm strongly pro-choice too. And I'm sure the traditional orthodox Jewish teaching is that for the first 40 days after conception, the "product of conception" has no significance. I believe this is from the Talmud. When I've mentioned it to anti-choice orthodox Jews on FR, they've agreed that was the teaching, but they have rejected it on the grounds that "they just didn't know about the biology of reproduction back then". Odd, from my standpoint, that these same people still feel the need to adhere to dietary rules that were clearly based on limited knowledge of food-based infectious disease. Cafeteria-style orthodoxy, I guess.
Thats interesting considering organogenesis occurs during weeks 4-8 of pregnancy
The traditional Jewish view of abortion does not fit conveniently into any of the major "camps" in the current American abortion debate. We neither ban abortion completely, nor do we allow indiscriminate abortion "on demand." To gain a clear understanding of when abortion is sanctioned, or even required, and when it is forbidden, requires an appreciation of certain nuances of halacha (Jewish law) which govern the status of the fetus.
Your quotes from orthodox Jews about abortion are wrong. No real orthodox Jews would say that the Torah's teachings are incorrect because back then "they just didn't know (... fill in the blanks here...)". The Torah is the word of God and so applies in all times. There are multiple reasons for each law, so although one reason may not apply, other reasons still do. Same applies to your remarks that "dietary rules that were clearly based on limited knowledge of food-based infectious disease". This just isn't so. The dietary rules have other reasons also, and God in His wisdom knows what they are even if we don't.