Is a foetus a person? The case of Adriana Smith, a brain-dead American woman whose body is being kept alive to carry her child to term, has sparked furious debate about personhood and autonomy.
Brain-dead mum kept alive to save baby
The road to birth: An embryo becomes a foetus at the end of the eighth week of pregnancy. Glossary
Ventilator - A machine used to replace someone's breathing.
Abortion - The deliberate ending of a pregnancy.
Constitutional - Relating to the constitution, a document that sets out the fundamental rules according to which a country is governed, which are usually difficult to change.
Foetuses - Unborn humans or animals in the later stages of their development, but before birth.
Embryos - An unborn or unhatched offspring in the process of development.
Caesarean section - An operation to cut into a woman's womb and deliver her baby.
Metaphysical - Relating to the branch of philosophy that deals with abstract concepts such as being, knowing, identity and space.
Mary Anne Warren - An American writer and philosopher (1946 - 2010), known for her writings on abortion and animal rights.
Sentience - The ability to experience feelings and sensations.
Autonomy - The right to make your own decisions.