Niigasa didn't become an empress due to her low social status but her child, Imperial Prince Yamanobe, was installed as the Crown Prince and went on to become Emperor Kanmu (he reigned from 781 to 806).
出自の卑しい新笠自身が皇后になることはなかったが、新笠が生んだ山部親王が立太子し、桓武天皇（在位：781年-806年）となる。