Murder in general is not detailed in the Constitution. Thus, abortion is not an enumerated power for the federal government to have a say.
Obviously there are federal limits on all state laws, including laws about murder, through things like the 14th Amendment's equal protection clause. (i.e. a state can't say it's illegal to murder whites but not blacks, or a state can't have a large punishment for murdering blacks than for murdering whites, thus the Dims' "hate crimes" legislation in various states is unconstitutional).
Throw it right back anthem with Partial Birth Abortion. Stay on offense!