In some instances, abortion is the deliberate expulsion of an embryo or fetus from the womb for the purpose of ending a pregnancy. Abortions also occur spontaneously as a natural process, sometimes overtly during early pregnancy. In spontaneous abortions, the term miscarriage applies. The term 'abortion' applies most commonly to refer to the termination of a pregnancy by artificial means, e.g. through surgery or drugs. Because the 'status' of the embryo or foetus is debated among philosophers and religious believers, among other groups and individuals in society, the practice of abortion is controversial.
In the United States, the controversy has involved the Supreme Court and the country at large, with the current legal status of the circumstances regulating abortion complex and in flux. The key court decision is Roe v. Wade.