This might end up being a bit long, but I want to share my experiences of the past couple weeks with regards to being assessed a high risk for Down Syndrome and give a bit of a trip report about our visit with the perinatologist and amniocentesis test.
My wife is 35 now, and will be 36 at the time she is expected to deliver the baby. This means that she is already assigned a slightly higher risk factor for the baby to have certain genetic defects, with the most common being Down Syndrome. She elected to have the
quad marker screen on the advice of her doctor, not expecting any issues to be found. Her appointment for this was on 12/19. On 12/26 she called me at work very upset. Her screen results came back "abnormal" indicating a high risk for
Down Syndrome (the doctor told her the risk factor was 1 in 88). They set up an appointment for us to see a specialist (perinatologist) for "genetic counselling" and further testing. Neither of us quite understood what that meant, so we did some web research to learn more about the results.
Through our research we learned that the prenatal screening tests triple screen and quad screen have a very high rate of
false positive results. What happens is the doctor plugs in several numbers into an equation that spits out a risk assessment. Some of those factors are the mother's age at the time of delivery, the blood test results, the due date, etc. This is how we were given the 1 in 88 risk factor. It really turns out that the actual chance of the baby having Down Syndrome is much less than that statistically speaking, but it caused us much anxiety as we waited for the appointment with the specialist.
We arrived at the specialist clinic on Wednesday 1/3 for our appointment feeling pretty positive that we would receive good news, but still anxious to get a diagnosis. The first step is to have what is called a
Level 2 ultrasound. This is a detailed ultrasound analysis where they check for soft markers (physical indicators that could indicate certain birth defects). Some of these include measurements of the head and long bones, inspecting the lining of the heart chambers, cysts on the kidneys, obstructed bowels, and several others. They also check for other indicators for birth defects such as club foot and cleft lip. This lasted about 45 minutes or so. After the ultrasound was complete we sat down and discussed the results with the perinatologist. She said that they did not see any soft markers for Down Syndrome, nor any other birth defects. This was a great relief to us, but the doctor told us that even with no soft markers on the ultrasound that we could still only be about 70% sure the baby didn't have Down Syndrome. The only way we could be positive was to have an
amniocentesis. There is a small risk of miscarriage with amniocentesis, but the doctor told us that it was actually a smaller risk than that of a natural miscarriage. She has performed 200-300 amniocentesis per year for 23 years and had 7 women have a miscarriage due to the amniocentesis during that time. It is a pretty expensive test, but we decided that we wanted to have the peace of mind and know for sure so my wife decided to get the amniocentesis.
The amniotic fluid is removed from the uterus using a 3 1/2 inch spinal needle. It takes about 2-3 minutes to draw off enough amniotic fluid to test. My wife said that it wasn't as bad as she had anticipated, but she did have some cramping for a day. It takes about 10 days to 2 weeks to get full results back from the test, but you can get some rapid results with a
FISH test. We got these reults back today and confirmed that the baby doesn't have Down Syndrome (the FISH test checks for issues with chromosomes 13, 18, and 21).
Sorry for the long post, but hopefully someone might find some of this information helpful.