Ethnicity and the need for correction of biochemical and ultrasound markers of chromosomal anomalies in the first trimester: a study of Oriental, Asian and Afro-Caribbean populations

Abstract

Differences in median PAPP-A, free beta-hCG and, to a lesser extent, in NT exist in Afro-Caribbean, South Asian and Oriental women. In populations where the medians and delta NT reference ranges are established in predominantly Caucasian populations, some correction for ethnicity is appropriate and can redress differences in screen-positive rates between these different groups.