I wanted to repost this here as it's a common question that comes up and I wanted to put it under better searchable terms. I'm also wondering if JM should put it up top. I know she went on vacation so maybe I will bring it up again when she is back. Please feel free to chime in if any of the info is not right, times etc. Once it's edited maybe it can go up top. I think it would be useful as sometimes you don't have much time by the time you get into see an OB to do these tests, and also I don't find the brochures that they give out all that useful or comprehensive.
1st trimester screen: 11-13 weeks, u/s (measuring nuchal translucency and looking for the presence of the nasal bone) and bloodwork that give you odds for the most common chromosomal abnormalities (including down's)
a new test, called MaterniT21, tests your bloodwork for small amounts of the baby's DNA and can tell you about whether the baby has the 3 most common chromosomal disorders (including down's). i think can be done as early as 9-10wks and has an accuracy of around 99%, but others may know more about this as they are using it it right now (insurance may not cover as it is a new test)
2nd trimester screen: also called AFP--18-21 weeks(?) bloodwork gives you another odds ratio for the chromosomal disorders, also can give you info about spina bifida and soem other things but my OB says these things would be seen on the level II u/s. My understanding is that this test is less reliable than the 1st tri screen (and thus I am not doing it) but others may have different info
level II u/s: 18-20 weeks, give good info about general health and development of the baby, and detects soft markers for down's.
Invasive (chance for inducing m/c-- can vary from practice to practice)
cvs: 11-13 weeks (?), detects chromosomal abnormalities
amniocentesis: 14-15 weeks onward, detects chromosomal abnormalities and spina bifida
this blood work can be done from 15-20 weeks. I am 16 weeks and having mine done this Thursday, just wanted to note that.
This is a great idea, very helpful! Good call out!