human life when not in utero. It defines "born alive" as "the complete expulsion or extraction from his or her mother of that member, at any stage of development, who after such expulsion or extraction breathes or has a beating heart, pulsation of the umbilical cord, or definite movement of voluntary muscles" and specifies that any of these is the action of a living human person. While the implications of this law for defining viability in medicine may not be fully explored, in practice doctors and nurses are advised not to resuscitate such persons with gestational age of 22 weeks or less, under 400 g weight, with anencephaly, or with a confirmed diagnosis of trisomy 13 or 18. U.S. state laws Forty-three states have laws banning post-viability abortions unless pregnancy threatens the life or health of the woman or there is a fetal abnormality. Some allow doctors to decide for themselves if the fetus is viable. Some require doctors to perform tests to prove a fetus is pre-viable and require multiple doctors to certify the findings. The procedure intact dilation and extraction (IDX) became a focal point in the abortion debate, based on the belief that it is used mainly post-viability. IDX was made illegal in most circumstances by the Partial-Birth Abortion Ban Act in 2003, which the U.S. Supreme Court upheld in the case of Gonzales v. Carhart. Limit of viability The limit of viability is the gestational age at which a prematurely born fetus/infant has a 50% chance of long-term survival outside its mother's womb. With the support of neonatal intensive care units, the limit of viability in the developed world has declined since the 1960s. As of the mid-2000s, the limit of viability is considered to be around 24 weeks, although the incidence of major disabilities remains high at this point. Neonatologists generally would not provide intensive care at 23 weeks, but would from 26 weeks. Different jurisdictions have different policies regarding the resuscitation of extremely premature newborns, that may be based on various factors such as gestational age, weight and medical presentation of the baby, the desires of parents and medical practitioners. The high risk of severe disability of very premature babies or of mortality despite medical efforts lead to ethical debates over quality of life and futile medical care, but also about the sanctity of life as viewed in various religious doctrines. As of 2022,