The law also requires the doctor to describe the fetus to the woman.
"We speak of invasiveness. An unborn child is forced to have an instrument forced into its body, killing it," Republican state Sen. Steve Russell said. "We speak of the poor and underprivileged. No one is more vulnerable than a child in the womb. They have no voice except ours."
Lawmakers passed the bill last March, but Gov. Brad Henry vetoed it and said it was unconstitutional.
In April, the Oklahoma Legislature overrode Henry's decision, causing the Center for Reproductive Rights in New York to step in. The group said the Legislature was aggressively stripping away a woman's privacy rights.
"This signals the beginning of another costly and possibly futile legal battle for the state of Oklahoma," Henry said after his veto was overridden.
In May, a judge temporarily blocked the law, leading to Monday's hearing. There was no immediate word how long the temporary block will continue or when the judge might rule.