Trébuchet and de Grouchy collaborated on this study, many years ago:
“Fetomaternal transfusion of blood lymphocytes and identification of the sex of the fetus” [article in French], J. de Grouchy and C. Trébuchet, Annales de Genetique, vol. 14, no. 2, June 1971, pp. 133-7.
BONUS (unrelated): A different sort of trebuchet:
Published on October 06, 2015 05:30