I am 37 old...at 12.5 weeks my dual marker & NT scan done ... trisomy21. (Background risk 1:170 & adjusted risk 1: 2637)FHR 160, CRL 62.6mm,NT 1.1mm, BPD 18.6 mm, Ductus 1.11 ,nasal bone present,all r normal..*posterior low Dual Marker trisomy21. (Background risk 1:238 & adjusted risk 1: 519), free bhcg 111.7IU/I (=3.422MoM),PAPP-A 2.780 (=0.791MoM), uterine artery 1.560(=0.965MoM), Mean arterial pressure 87.8(=1.0267MoM) Concern : in my dual marker interpretation it says "intermediate risk" for down syndrome and low risk for late onset pre eclampsia... Why there is intermediate risk.. please reply