There are many references in the Bible to child sacrifice, and how much God detests it. For example, II Chronicles 28:1-3:
Ahaz was twenty years old when he became king, and he reigned in Jerusalem sixteen years. Unlike David his father, he did not do what was right in the eyes of the Lord. He followed the ways of the kings of Israel and also made idols for worshiping the Baals. He burned sacrifices in the Valley of Ben Hinnom and sacrificed his children in the fire, engaging in the detestable practices of the nations the Lord had driven out before the Israelites.
People sacrificed (and still do) their children to please or appease their gods.
A god does not have to be a deity. Idol worship can take many forms – love of money, love of power, addictions, obsession over another person, etc.
In that context, is there any difference between ritualistic child sacrifice and abortion? How are the two alike, or not alike?