Originally Posted by
Slybak
1) 20 week bans have nothing to do with fetal viability. They're actually designed to undermine a fetal viability standard.
2) The actual numerical limit isn't as important as the legal principles that form the basis of those numerical limits.
The limit of viability is 24 weeks, meaning that at 24 weeks a fetus has a greater than 50% chance of surviving outside the womb (and this includes putting it in a neonatal ICU). This is the "third trimester" standard introduced in PP v Casey in 1992, which established that only at the limit of viability can the state intervene against the termination of a pregnancy to protect the liberty interests of the fetus. Before 24 weeks, the pregnant woman's liberty interests hold sway.
When the architects of the decision (which pretty much means former Associate Justice Sandra Day O'Connor) set this standard, they did so under the assumption that medical science would continually advance to the point that the limit on viability would be further reduced into the second trimester. That hasn't happened. Nearly 25 years later, the limit of viability is still 24 weeks, as it turns out that there's not much doctors can do to keep a <6 month old fetus alive in an incubator. The fetus is still entirely dependent on the placenta to process nutrients and remove cellular waste; until around week 22 it hasn't even started to produce its own red blood cells.
What the 20 week limit does is replace the fetal viability standard of Casey with a new maternal health standard. At 20 weeks, fetal blood tests and sonograms will have ruled out any chromosomal or anatomical deformities that are the typical causes of miscarriages and maternal mortality. A pregnant woman who gets an abortion after 20 weeks does so because they went to the OB/GYN one day and got some truly terrible, soul crushing news; either the fetus is likely going to die in utero (and will put her life at risk from things like infection and septic shock), or has a high chance of causing severe internal damage if the pregnancy continues.
Why does this matter? Because replacing the fetal viability standard of Casey with this new maternal health standard actually puts the "liberty interests" of the fetus ahead of the woman's interests at every stage of pregnancy. It's no longer a matter of "does the fetus have a reasonable chance of surviving independently of the woman carrying it," but "does continuing the pregnancy undermine the ability of the woman to remain alive." Under this rubric, the state has far greater power to intervene against terminating a pregnancy, and its under this standard that various TRAP laws (targeted restrictions of abortion providers) have been put into effect in several states. Under a dishonest guise of "protecting the health of the mother," state governments have enacted draconian regulations to shut down abortion providers.
And that's the point; to make the choice of getting an abortion much more difficult in practical terms, not protecting anyone's actual health. Again, these 20 week limits have been implemented precisely because medical science hasn't reduced the limit of viability below 24 weeks, which was the assumption guiding Casey.
6 week limits, or so-called "fetal heartbeat" restrictions, are even worse. Instead of fetal viability or maternal health, these laws enshrine the "liberty interests" of the fetus as paramount under all circumstances, with the added bonus of setting an arbitrary "personhood" standard so close to the point of insemination that most women will surpass that limit before they even find out they're pregnant. Medically and legally, a pregnancy begins on the first day of a woman's last menstruation, and women who do not intend to get pregnant will likely not begin to suspect they are pregnant until they're subsequent menstruation is one or two weeks late. These laws are specifically designed to ban abortions in all circumstances.