New developments in prenatal screening for Down syndrome

Since the introduction of the triple screen, the emergence of additional analytes found to be associated with trisomy 21 pregnancies has challenged the clinical pathology and obstetric communities to determine which combination provides the best performance characteristics as a screening test. The cost, practicality, and psychosocial and ethical dimensions of different screening regimens further complicate the issue. This review attempts to give an overview of the various markers, current methods of screening, and most promising recent developments in antenatal screening for Down syndrome, with an emphasis on performance in prospective studies that have emerged during the last few years, rather than on estimates from statistical modeling.