-
Inverted Pyramid of Care.
Sonek JD, Kagan KO, Nicolaides KH.
Clin Lab Med 2016;36:305-17. pdf -
First-trimester contingent screening for trisomy 21 by biomarkers and maternal blood cell-free DNA testing.
Nicolaides KH, Wright D, Poon LC, Syngelaki A, Gil MM.
Ultrasound Obstet Gynecol 2013;42:41-50. pdf