Fig. 1.

Absolute quantification of ubiquitous and chromosome 21-derived extracellular microRNAs in non-pregnant women, normal pregnancies and those bearing DS foetuses. Concentrations of extracellular microRNAs in plasma samples were subtracted from the standard curve and expressed in pg of total RNA enriched for small RNAs per millilitre of plasma. Absolute quantification of particular microRNAs was compared between the individual groups using the Mann-Whitney U-test (P<0.25). *, extremes; ○, outliers.