Abortion laws vary widely across the world, with some countriessuch as Nicaragua and Chile banning abortion outright, while otherssuch as Canada have no criminal punishment for abortion. Mostcountries' laws fall somewhere in between. In the United States,per the Supreme Court's landmark decision in Roe v. Wade,unrestricted abortion is allowed until the fetus has reached thepoint of viability, or the ability to survive outside of the womb.Viability is generally considered to occur around 28 weeks,although advancing medical technology is making it a possibilityearlier in the pregnancy. Once the point of viability has beenpassed, abortions are legal only in cases in which the procedure iskey to a woman's physical or mental health. In 2003, thePartial-Birth Abortion Ban Act was passed and sign