Idaho is the first state to have a fetal pain abortion ban struck down after a federal judge overturned the law banning abortions after 20 weeks.
The judge said the Supreme Court has ruled that a woman has an absolute right to an abortion before the point of viability.
The March 6 ruling also overturned other abortion restrictions in Idaho.
Ten states have enacted fetal pain laws since 2010. Only three states have had the laws legally challenged.