Risk of Downs Syndrome

[HotI]

I know a woman who had CVS and had a terribly damaged placenta with several different trisomies. She declined a termination because one of the trisomies always results in foetal death anyway and she felt she'd rather let the baby pick its time to go, as it were, but now she has a 3 year old, healthy, son. The placenta had abnormalities which the baby did not. No, i don't know how this works, presumably something to do with RNA versus DNA (Ryn where are you?!) but still a scary (for me) story. They cannot give absolutes in the tests, they can only give a most-accurate guess. Nothing is certain.

This can happen more readily than the reverse ('normal' placenta, baby with chromosomal variations). The cells that form the placenta are 'older' cells than those that form the baby. These cells keep dividing to produce more cells (so the placenta grows) and this is when mutations can occur.

A 'mutation' or change can occur in these cells that does not affect the baby. So some cells in the placenta may have more or less chromosomes than the usual number. There are some changes that the lab people know occur in placenta that would not be present in the baby. Other changes, like an extra chromosome 21 found in some of the placenta cells (but not all) can make it harder for the lab people to say whether the baby may also have some or all cells with an extra 21.

In this situation, a Mum may be offered a follow up amino bc this looks at cells that come from the baby. All these changes are in the DNA. Chromosomes are made up of a long string of DNA wound tightly. When a cell divides into two new ones, one of each chromosome goes to each of the new cells. If the chromosomes don't line up properly, you can get two chromosomes of the same type going in to one new cell, and none of that type going into the other new cell.

If a change occurs in a baby cell, it is usually repaired. If the change is a serious one and not repaired, the baby will not survive.

[nangari]

Wow what a positive thread. How lovely!! I met someone recently who had an amnio and was told her baby was 'fine' all clear. Her baby has mosaic Down Syndrome that was not picked up when they counted the 15 cells of the amnio. It was picked up however at birth and it only took 7 cells to find one with 47 chromosomes....so yes, it can happen.....

And yes, these tests do NOT predict in any way shape or form, what your baby will be like and how you will cope with looking after it. I bet all of us have been surprised by our parenting in one way or another now that we have children....

I would strongly recommend skipping the testing as it only creates worry....I have a friend who has just had her first baby and her pregnancy was wrought with worry as the docs (she saw at least 8 different ones) were worried about the size of her bub. Not to mention her and her hubby are not that big! ggrrrr so she spent weeks worrying about baby not growing properly, placenta maybe dying etc....wondering how she would cope with an induction blah blah blah. It was so unfair. She ended up having a reasonably good birth and her baby was on the small side but perfectly normal and healthy. I can understand that doctors have to go by numbers and that some babies are in fact saved this way but really....!!!

For what it's worth, I have a child with Down Syndrome and she's perfectly normal and healthy. She has no health issues and although she picks up things a little slower than others, she's by no means a dunce! It saddens me that people are scared of people like her - after all, she's people like us I'd love to help allay people's fears.....

Cas