hi doctor, i have a doubt about double marker test, we did just now... trisomy 21+NT Risk (biochemi+NT)== 1:2270 Trisomy 21 (Biochemi)== 1:658 trisomy13/8+NT(Bio+NT)== Age risk== 1:18C Overall:- Trisomy 18 screening, 21 screening == Negative and low risk. Is any abnormal in this test, little worried since low risk is written, (ideally no risk?) pls some guidance on this report please... thanks you for valuable time...