Oklahoma Gov. Mary Fallin vetoed a bill that would have made it a felony for doctors to perform abortions in the state. The Republican governor said the legislation would not have stood up against a constitutional legal challenge.

“The bill is so ambiguous and so vague that doctors cannot be certain what medical circumstances would be considered ‘necessary to preserve the life of the mother,'” Fallin said Friday afternoon. “The absence of any definition, analysis or medical standard renders this exception vague, indefinite and vulnerable to subjective interpretation and application.