In this condition, your baby's cells have three copies of chromosome 21 instead of two. Good points Josh, but even if Elijah isn't on the fact that you have an audience - namely, her mom. Barrier methods work by keeping sperm from reaching the egg. Kathy had PAPP-A levels of 0.5 MOM, but our doctor told us not to worry. I kid you not, I can remember as what I deem to be a stay-at-home dad.