States where the legal limit is fetal viability are shown as having a limit of 25 weeks. Fetal viability is a medical term used to describe the point at which a fetus can survive outside of a womb. The point varies in each pregnancy, and is usually reached between 22 to 25 weeks.

All weeks measured from date of last menstrual period. Some clinics indicate the gestational age in days (e.g. 11 weeks and 6 days); this chart rounds to the nearest week.

Source: INeedAnA.com
Chart: Jasmine MithaniThe 19th・19thnews.org