Deliberate induction of abortion is as old as human understanding of the cause and symptoms of pregnancy, but the gradual transition of its legal characterization from a crime to a legitimate healthcare intervention, and then to a woman's human right, is an international evolution of only recent decades, and remains contested and resisted. This is addressed in a new book, Abortion Law in Transnational Perspective: Cases and Controversies, which explains, in its Introduction “The field of abortion law has survived several revolutions. Perhaps the greatest is the shift in focus to human rights,” particularly women’s rights.

In ancient times, herbalists practicing as healers induced abortions through plants with recognized medicinal properties, such as pennyroyal and angelica. Such treatments were usually administered, however, by matrons and midwives applying “women's knowledge,” and in the late medieval period in Europe, the Church, with encouragement from the exclusively male practitioners of the emerging science of “physick”, suppressed them as witches. Women thereby lost control of this reproductive option. Unskilled applications of toxic herbs are liable inadvertently to injure women, and the first English legislation addressing induction of abortion, enacted in 1803, was designed to save women from related harms and risks of death. Lord Ellenborough's Act of 1803 made it a felony, punishable by death, to administer "...any deadly Poison, or other noxious and destructive Substance or Thing...thereby to cause and procure the Miscarriage of any Woman...." Women terminating their pregnancies were not included as offenders, but later enactments made such women receiving treatment, or acting alone, liable as lesser offenders.

In the English-speaking and British-ruled world, legislation governing abortion took forms in the mid -19th century that remain influential today, through the Indian Penal Code of 1860 and particularly the English Offences Against the Person Act, 1861. Section 58 of the 1861 Act provides that " Every Woman, being with Child, who, with Intent to procure her own Miscarriage, shall unlawfully administer to herself any Poison or other noxious Thing, or shall unlawfully use any Instrument or other Means whatsoever with the like Intent and whosoever, with Intent to procure the Miscarriage of any Woman whether she be or be not with Child, shall unlawfully administer to her or cause to be taken by her any Poison or other noxious Thing, or shall unlawfully use any Instrument or other means whatsoever with like Intent, shall be guilty of Felony."

This language, reinforced by offenders' liability to imprisonment for terms up to life, created a popular impression that remains today in several countries once under British rule, that induced abortion is criminal in all circumstances. It was not until 1938 that an influential English court, the Central Criminal Court in London, at the Old Bailey, drew significance from the word "unlawfully" being used four times in section 58 to qualify offenses against the section. In the case of R. v. Bourne, in which a prominent doctor in a public hospital admitted procuring the abortion of a 15- year-old girl pregnant by rape, the judge interpreted the section to allow lawful abortion. He directed the jury that if they considered that pregnancy was terminated in good faith to preserve the woman's life, which includes her physical or mental health, they should acquit the defendant, which they did. This ruling was quickly invoked in America, by a court in Boston, Massachusetts, and is widely accepted today as the correct understanding of the law where wording in the 1861 Act, or slight variants thereof, remains legally applicable, although this understanding is rejected in the Republic of Ireland.

The 1938 interpretation exempts medically-determined indications for requesting and performing abortions from punishment under criminal law, but in the U.S.A. in 1970, a challenge to criminal abortion law was successfully mounted on the more fundamental basis of constitutional law. The focus of the landmark ruling of the U.S. Supreme Court in its 1973 decision in Roe v. Wade, concerning the law in Texas, and its less discussed companion case from Georgia, Doe v. Bolton, was whether abortion could be subsumed under a right protected in the U.S. Constitution. The Court, consistently with the American emphasis on individualism and distrust of "big government," found that a constitutional right of privacy exists, with which legislatures cannot interfere, that allows abortion prior to fetal viability.

While other countries were absorbing whether this ruling and its underlying recognition of women's rights had implications for their own law, the German Federal Constitutional Court, in 1975, handed down its contrasting ruling that addressed the constitutional duty of the state to show the respect that must be afforded human life, including of the unborn. This reflected German sensitivity to how, little more than three decades earlier, the state had treated the lives of vulnerable populations as legitimately extinguishable. The Court struck down liberal abortion provisions, and ruled that respect for fetal life requires that women seeking abortion must receive prior dissuasive counseling.

Both the 1973 U.S. and 1975 German rulings have been judicially refined, U.S. law becoming more restrictive, German more accommodating. However, drawing upon medical and related indications to allow lawful abortion, women's rights to reproductive self-determination, and/or protective state duties towards unborn human life, leading courts in Europe, Central and South America, Africa and Asia are resolving conflicting interests in their abortion laws to afford a transnational perspective on developments, as discussed in the book mentioned above. The book’s Table of Cases has recently been put online with links to relevant court decisions.

For instance, the Supreme Court of Brazil, accepting that abortion prohibitions protect fetal viability, ruled them inapplicable to anencephalic fetuses because on live birth they are inherently non-viable. The Supreme Court of Nepal, invoking women's rights to equal dignity and health care with men, reversed a long history of severe punishment of women due to religious condemnation of abortion, and now requires state provision of services, including to poor and socially-marginalized women. Balancing different approaches, the Portuguese Constitutional Court in 2010 approved abortion on request during the first 10 weeks of pregnancy, and mandatory but not dissuasive counseling thereafter to inform women's "free, conscious and responsible" decisions to terminate or continue their pregnancies.