The US Supreme Court has voted to allow the continued use of abortion pill mifepristone as legal appeals continue. 

The decision made Friday night stayed lower court rulings restricting its use and returned the issue to the 5th Circuit Court of Appeals for a full hearing on 17 May. 

"We are hopeful that when the court takes up the expedited hearing on May 17 that it will confirm the fact that these drugs are dangerous to women," said Carol Tobias, president of National Right to Life.

The future of mifespristone in the US has been in question since the Alliance for Hippocratic Medicine filed a lawsuit against the US Food and Drug Administration (FDA) arguing that the agency unlawfully fast-tracked the approval of the abortion pill through a process intended for the treatment of life-threatening illnesses.

Texas court judge Matthew Kacsmaryk ruled against use of the drug earlier this month, concluding that the FDA's approval had violated federal rules.

"The US Supreme Court gives the full 5th Circuit the opportunity to evaluate the case on its merits and review the materials presented to them in a timely fashion," Tobias continued.

"What the courts will see is a drug that does not cure a disease or alleviate the symptoms of a disease. It was developed to take the life of an unborn child and always has the potential to harm the mother."