Protection of man's life is not limited only to postnatal life in Islam, but it also includes the life of an embryo. In the eyes of Islam life during the prenatal life (embryos) and even before an embryo is formed is subject to protection. Depriving an embryo of life through abortion is a crime and a sin. And he who commits this crime is entitled to punishment. The existence of mankind starts since joining of two primary cells. Therefore, according to The Holy Quran destruction of it at any stage means depriving mankind of life
Islam does not allow abortion for the purpose of birth control (except in some exceptional or emergency cases). For the life of an embryo in every stage of evolution/perfection, since the time a sperm is placed inside a woman's uterus and since the beginning of growth and ultimately developing into an embryo is fully under the protection umbrella of Islam and abortion or destruction of embryo is considered a murder and is unlawful.
In Islam even an embryo which is the result of adultery is protected and abortion is unlawful. In other words you cannot deprive such embryo of life either; just because the sexual intercourse was unlawful it does not justify your terminating the life of the embryo.
Islam does not ban birth control. There is no decree prohibiting a couple to decide to prevent pregnancy. However, once a woman gets pregnant the parents have no right to destroy the embryo which means depriving it of life. Many theology scholars argue that once an embryo is formed an independent entity with life is emerged, that apart from a mother independently has the right to have life. And except in emergency cases determined by the Islamic law nobody even the parents have the right to deprive and embryo of life.
Even those Islamic scholars who have considered the embryo a part of a mother's body still argue that nobody has the right to cut any part of her body and therefore a mother is not allowed to have abortion operated on her. Apparently if the crime of abortion is committed by a third party (other than the parents), even it is not done deliberately, still her/his action is a sin, which entitles her/him to punishment both in this world and the Resurrection Day.