Hi all just got a letter through for my downs, T18 and t13 testing. The results Free b-hcg - 18.5 ng/mL 0.48 MoM PAPP- A level 3729 miu/L 0.59 MoM Downs- <1 in 50,000 T18 - < 1 in 50,000 T13 - 1-30,000 I know these have all come out as negative but why the 20,000 difference for t13 and what are the normal hcg and PAPP Levels At the time of the test I was 12 weeks and 6 days. They have given a number to call for questions but they are closed so I thought I would ask you lovely people thank you :)