2009, Catherine Playoust & Ellen Bradshaw Aitken, "The Leaping Child: Imagining the Unborn in Early Christian Literature", in Imagining the Fetus: The Unborn in Myth, Religion, and Culture (eds. Vanessa R. Sasson & Jane Marie Law), Oxford University Press (2009), ISBN 9780195380040, http://books.google.com/books?id=fOe3jsja4OwC&pg=PA176 page 176:
Whereas the lack of a child brings shame upon Anna and Joachim, the converse holds true for Mary: the existence of an unborn in the womb of a woman who is supposed to be a virgin causes great scandal.