The court, without comment, lifted a stay imposed Friday by Justice Clarence Thomas, the Washington Post reported. When the court refuses to hear a case, it does not release a breakdown of how justices voted, so Chief Justice John Roberts' position is unknown.
Missouri argued a law banning public money from being used for abortions applied even though the procedure would be paid for privately because the Department of Corrections would have to supply transportation and guards.
A federal judge ruled the state could not interfere with the woman's right to terminate her pregnancy guaranteed by the Supreme Court's Roe vs. Wade decision.
"It is not the prison that has imposed the burden, but the prisoner's violation of the law that resulted in her incarceration that has imposed the burden," Assistant Attorney General Michael Pritchett said in a legal brief. "And, even if the result were plaintiff carrying her child to term, it ought not be held that this result -- having a child -- is a harm at all, much less an irreparable one."