Republican Gov. Bill Haslam has signed legislation into law to ban abortions in Tennessee after 20 weeks if a doctor determines the fetus is viable through required tests.
The legislation that subjects doctors to felony penalties doesn't apply if the mother faces risks of death or serious damage to a major bodily function.
State Attorney General Herbert Slatery has said his office would defend the measure in court despite previously calling it "constitutionally suspect."
Supporters of the bill contended it can withstand a constitutional challenge, comparing it to 20 laws in other states. They said the bill protects unborn children.
Some Democrats argued that the bill remains vulnerable to a court challenge and say it bucks established medical standards while interfering with a woman's ability to make a deeply personal decision.