CHICAGO (Reuters) - An appeals court on Friday upheld much of a South Dakota law setting out what a pregnant woman should be told 24 hours before an abortion, including that the procedure would "terminate the life of a whole, separate, unique, living human being."

The 8th Circuit Court of Appeals ruled against a provision in the 2005 law that would require the doctor to tell the woman about an increased risk of suicide after an abortion -- with the court saying the link was unproven and may not exist.

The appeals court overruled a lower court's rulings on South Dakota's law in one respect -- it backed the state's position that pregnant women should be told that they have an existing relationship with the fetus.

The statement assures the woman that she should not feel pressured into having an abortion, the court said. The statement "conveys legal information that is truthful, not misleading, and relevant to the abortion decision," the court said.

In its 17-page ruling, the appeals court upheld the lower regarding requirements that doctors advise women that the procedure will "terminate the life of a whole, separate, unique, living human being."

Planned Parenthood, which operates the state's only abortion clinic, and the state both appealed after the lower court delivered a mixed ruling on the law.

Some other states have passed so-called informed consent laws. But South Dakota has been at the center of some of the most bitter recent fights over abortion, which was legalized in 1973 by the U.S. Supreme Court in Roe v. Wade.

(Reporting by Andrew Stern; Editing by Greg McCune)