In the Us, one of the two forms of murder legal in the US, considering that a baby born prematurely would be fully protected by the law, while inside the womb it could be aborted.
Some people argue that abortion is also infanticide. In some cases abortion is needed to save the pregnant mother because of severe medical problems that would result in the death of the pregnant mother, but in other cases abortion has been used as an elective surgery to terminate an unwanted pregnancy.
There are different forms of abortions from Medical Abortion, Therapeutic Abortion, Spontaneous Abortion, Induced Abortion, Surgical Abortion, Sex-Selective Abortion, Backyard Abortion and Elective Abortion.
In some countries infanticide has been argued that if a child is born with a congenital disorder or significant morbidity i.e. very retarded or fucked up, that infanticide should be allowed. This is in my opinion could also be called Infant Euthanasia or murder.
Child sacrifice is another form of infanticide.
To leave your baby in the middle of nowhere to the elements of nature is infanticide.
To abandon your baby to die because the baby is female and you have to pay a dowry is female infanticide.