I'm a little confused about the chances my baby has with down syndrome. I had my ultrasound and it came back that there could be something a little off with the heart that could be a sign of down syndrome but I also had the maternal serum screening which came back almost perfect.
My doctor says that the chances are very low but we are going to do another ultra-sound to double check. She was saying that it is possible that the technician took the picture from a funny angle or something like that. She insisted that there would be nothing else wrong with the heart.
So I was just wondering which is more accurate, the ultra-sound or the screening? I understand the chances are low but I would like to be prepared. Oh, I am 26 years old and this will be my 3rd baby.
asked 28 Nov '10, 14:24
We went to a genetic specialist this morning to get more information. The numbers seemed to jump up and down and he explained things. I wish I could remember them all now but I will give a general idea of what happened.
Because of my age and background we started with a 1/13000 chance of having a baby with down syndrome and my serum screening (blood test) came back perfect that went way way down and T18 went down even further. So chances went to basically non-existent.
Then we had the ultrasound which had a few abnormalities (we only knew about the heart).
First he told us that baby has a cyst in it's brain which a lot of normal children have. But this could be a sign of T18 so our chances of having a baby with T18 went up but still to a basically nonexistent number.
Then he told us about the heart. Basically in the ultrasound they saw a 'bright spot'. So our chances of Down Syndrome went up slightly. Also many normal kids have this.
And then he said something about the bowels having a bright spot but he said that it wasn't bright enough that he would have even mentioned it. But IF it had been our chances after all of this of having a baby with Down Syndrome would be 1/800.
So in the end of it all our chances seem no better or worse then if we had known nothing at all.
Based on your description, it sounds like so far you've only had the screening tests, not a diagnostic test. According to the Mayo Clinic, screening tests are not used for diagnosis of a particular condition. Instead, they are used to determine if more in-depth diagnostic tests are appropriate.
Even if you have another ultrasound that looks the same as your first, it's not conclusive. According to another article by the Mayo Clinic:
About one in 20 women will have a positive result with any of these screening tests — far more than those who eventually deliver a baby with a chromosomal abnormality. In fact, most women who have a positive result from a screening test deliver healthy babies.
When I was pregnant, my doctor recommended I take the First Trimester screening. For me, this consisted of going down to a clinic where they took my family history, a blood test, and then an ultrasound where they measured the fetus's nuchal translucency. After receiving the results, they estimated my risk based on all three factors. It turns out that my risk was low enough we didn't proceed any further. However, if the risk had been higher, I would have participated in genetic counseling to decide if I wanted to take the next step which would be diagnostic tests such as amniocentesis.
answered 29 Nov '10, 03:55
I'm not sure how it works wherever you're located, but where we live, the ultrasound is part of the screening (details available from the Ministry of Health screening site) so it's not really possible to say if one or the other is more accurate.
What we had is called Integrated Prenatal Screening (IPS) (see second column on that page), which consists of two blood tests and an ultrasound. The results from all three are combined to give either a "Screen Positive" or a "Screen Negative". A "Screen Positive" does not necessarily mean that you'll have a child with Down's (or Trisomy 18, or any of the other things that are screened for) as most "Screen Positives" are false positives.
In our case, we had a "Screen Positive" on our second child, and because we're the kind of people who just have to know what's going to happen, we chose to have amniocentesis (note... the risks of amnio are significantly lower than the "1 in 300" that most people are told. More recent studies show that it's more like 1 in 1600). The amnio results showed that the screen positive was a false positive, and our son was born without any chromosomal abnormalities.
answered 29 Nov '10, 07:33