Infanticide or killing recently born children is considered a crime because such an entity is regarded as a human being.
Abortion, however is not considered a crime because a fetus is not regarded as a human being.
What is a human being? Quite obviously the psychological sense of self or the capacity for an intellectual conception of the world is the essence of man. An infant does not have a mind of a human. He is in closer affinity with most animals than humans for this reason.
Because an infant is not a human, he ought not to be granted the right to life and is therefore the property of the state or his biological parents. It is up to one of the two to decide whether the infant should live or die.
The fact that he has potential to become a human being is irrelevant because law by definition deals with entities that are and not entities that could be.
A normal child may be dispensed with until he has reached the age of 2, or clear-cut psychological functioning. A child afflicted with mental retardation may be killed until he has reached the age of 5.
Thus in summary, one should not be awarded the basic human rights until one becomes human or acquires a psychological sense of self, until then he is to be regarded as property of those who do have such a sense of self.