In any civil action in which the paternal or maternal relationship of one person to another is sought to be proved by use of blood tests, the costs of such tests shall be paid by that party upon whom the blood test is to be performed, except that the plaintiff shall pay the cost of any test administered to a child if a minor. Upon entry of judgment, the court shall award to the prevailing party any cost incurred by him or it under this section for the administration of such blood tests.