I was just reminded of this thread. I just thought I'd update (for anyone researching in the future) that my high HCG was linked to low Papp-A, which in turn did put us at a high risk for DS. Luckily for us DD2 was fine, but the low Papp-A meant we had placenta issues which caused many problems which for us resulted in severe IUGR, an early delivery at 36 weeks (at which point DD2 was just 1.84kg) and a stay in SCN. She's perfect now though!