Abstract
A growing number of states have banned abortion after twenty weeks on the grounds that the fetus at that stage experiences pain. Such laws run contrary to current abortion law, and so are almost certain to be challenged in court. In Roe v. Wade the Supreme Court said that the constitutional right to abortion extends until the fetus is viable, between twenty-four and twenty-eight weeks. After viability, states may ban abortion entirely except where continuing the pregnancy would threaten the woman’s life or health. The viability threshold was upheld in Planned Parenthood v. Casey. Maternal health should be paramount. Why viability? The Roe court said that this is “the ‘compelling’ point....