AZ enacted a law in April 2012 banning abortions at 20 weeks and later (measured from last menstrual period) due to evidence that fetuses can feel pain at 20 weeks.  This was ruled unconstitutional by the 9th Circuit Appellate Court in San Francisco because Roe protects a women’s right to abortion before a fetus is viable, and a fetus is not viable until ~24 weeks.  The SCOTUS refused to hear the case, and thus the ruling stands.

Judge Kleinfeld, from the 9th Circuit court, had said, “Were the [AZ] statute limited to protecting fetuses from unnecessary infliction of excruciating pain before their death, Arizona might regulate abortions at or after 20 weeks by requiring anesthetization of the fetuses about to be killed, much as it requires anesthetization of prisoners prior to killing them when the death penalty is carried out.”