There are some rights which the state has authority to confer (such as citizenship) but there are also fundamental rights of human beings. Fundamental rights, including the right to life, are inherent to, and derive from, the dignity of the human person. These rights are not bestowed by governments but must be recognised by them and protected in law. The right to life and equality is enshrined in a number of international human rights instruments.
Article 3 of the Universal Declaration of Human Rights begins the articulation of the human values to be defended in terms of human rights. "Everyone has the right to life, liberty and the security of person."
There is no agreed basis for dividing up the human family into persons and non-persons, but there is an agreement from science that from fertilisation we all share a common humanity, that we are all members of the "human family", to use the Declaration's words. The attempts to disenfranchise some members of the human family from moral consideration has led to justifications of intolerable abuses of human rights including slavery and genocide. The Declaration, following the United Nations Charter, rejects discrimination against any members of the "human family", and requires the "recognition of the inherent dignity and of the equal and inalienable rights of all members of the human family".
Also, the UN Convention on the Rights of the Child states that: "The child, by reason of his physical and mental immaturity, needs special safeguards and care, including appropriate legal protection, before as well as after birth." (Declaration on the Rights of the Child,1959). This is the most widely ratified human rights treaty in the world.
It is true that the practice of abortion is widespread and, in many countries, legal at least in some circumstances. There is, however, a mismatch between the human rights requirements of international law and the practice of individuals and nation states. Prohibitions on abortion by sovereign states are not only compatible with the requirements of international human rights instruments but are in fact the most probable interpretation of those requirements. It would therefore not only be wrong but foolish for an international human rights organisation such as Amnesty International to adopt a policy in favour of abortion.
For further information on the rights of unborn children, please read "What rights, if any, do the unborn have under international law?" by John Fleming PhD.