There are four separate, but overlapping parameters that inform an answer to this question and they are:
the moral the legal the philosophical the religious
Morally, if the intention of both concerned in sexual intercourse was to create a child, then the conception is an agreed event and both have a moral obligation to take into account the others wishes in terminating the pregnancy, provided there are no other complimenting issues such as the health of the fetus, the health of the mother or the father. However, if the conception is unplanned by both or either of the parents, or if the conception has resulted from an illegal event, then morally the mother has the right to choose whether or not to carry the pregnancy to term.
In law, in some countries, abortion is legal within certain specified parameters. Where these parameters are met the law in most countries allowing abortion recognises the mother as having the sole right to decide issues involving her own body.
Philosophically the argument turns around the issue of ownership in the sense that the organism owning the product of organic activity (the organism - the woman, owns the product of her organs - egg cell, fallopian tube and uterus)has the right to decide on abortion. The philosophical, "test," for this is provided by the fact that the organism (woman) can spontaneously abort a fetus.
The religious parameter causes individuals who adhere to certain religious beliefs the most searching question to have to resolve in that those religions disallow abortion of any form at any time post conception or restrict the act of abortion to situations where to continue the pregnancy would risk death or serious health complications for the mother. Within this parameter there is no provision for the father's views.
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