A friend of mine's daughter is having a baby. Last week, at 13 weeks, she went and had blood work done and her doctor came back with the results saying that her blood tested positive for down syndrome. When they did an ultrasound a couple of days later, the doctor said that everything with the baby looked fine. I didn't think they could tell if a baby had down syndrome that early on. What is the possiblity of it being right, and what are her options? Any light on this subject would be very helpful, this was a big surprise.
Last edited by JennaLynnK; 10-08-2005 at 03:51 PM.
I know there can be false positives and false negatives with the blood work. I hear about all the time. Thats why I opted not to get those tests done. As far as I know, with the ultrasound they check certain parts of the baby's body for signs of down syndrom. I think by looking at the fluid on the back of the neck and how big their bones are can give an indication if the baby could possibly have down syndrom. Not quite sure exactly what they are looking for. But I would tell her not to worry because more than likely, even though the doctors advise ultrasounds are not 100%, (mostly for liability reasons) I would think they checked over the baby thoroughly enough to see if anything was not normal.
Hope that helps a little. I just hear about these false positives all the time and the poor moms get all beside themselves and then everything turns out to be fine.
the only way to get an accurate result is cvs or amnio, as far as i know bloods and u/s only tell you your risk for downs for example 1in1,876, 1in25, etcand then you have to decide if you want cvs or amnio to check for sure.
I had the sameproblem. I caused much unneeded anxiety and stress. I had 2 triple screens and three ultrasounds....I opted for amnio just to be certain....its over 95% accurate. I know what she's going thru....its an emotional rollercoaster
I'll pass all this information along to her. It will help a little bit, thanks so much, but she is just so worried the only thing thats going to ease her mind is the doctor telling her that everything is ok. I appreciate everyones help
It depends on what blood test she had. The Triple screen (standard) has a false positive rate of like 67%. And, it's not a test for DS, it's a test for "the increased risk of DS"....big difference) Even if you have a positive result, it just means you are at a higher risk. NO blood test can diagnose DS. There is a newer integrated quad screen (called the integrated maternal serum AFP) that checks blood levels twice during pregnancy. Once in the first trimester, once in the second. Those results are analyzed and can predict at about 90% accuracy (ie 10% false positive rate) I had the triple screen in my first pregnancy and the IMSAFP in my second. In fact, I was one of the first to have it done in this state. My results were normal, lowering my predicted risk of DS from 1/300 to 1/5000. Soooo, at 36 I was never presented with the option of an amnio (which carries a risk of 1/200 for miscarriage anyway). My baby was fine. The U/S can check for certain markers in DS (cardiac abnormalities, increase thickness in neck folds, length of long bones in legs etc), but it cannot diagnose or rule out with 100% Even if all markers are present, a doctor cannot diagnose DS with an U/S. The ONLY way to determine for sure is an amnio or CVS (done earlier in pregnancy that amnio, but with higher risks). That looks at the actual chromosomes and can say with 100% (or 99.999%) accuracy that DS does or does not exist. The difference here is that an amnio or CVS can diagnose DS, the U/S can screen for possible markers and the blood tests screen for increased risk.