After the initial CVS results had come back clear, we still had the more detailed results to come back which would take up to 2 weeks. On the initial results phone call the midwife explained that they had only got a small sample and the lab was unsure if they could create the amount of cultures needed for the remainder of the tests.
I wasn’t too worried at first, after all it was the Downs Syndrome that we were most concerned about, but waiting for results is just horrible.
So what do they look for?
The two types of laboratory test are used to look at baby’s chromosomes:
- a polymerase chain reaction (PCR), which takes up to three working days
- a full karyotype, which takes two to three weeks
The PCR counts the number of chromosomes. There should be 23 pairs. If your baby has an extra chromosome (called trisomy), and if this extra one is chromosome 21, then Down’s Syndrome will be diagnosed.
A third copy of chromosome 18 means your baby has Edwards’ Syndrome, and three of chromosome 13 indicates Patau’s Syndrome. These two conditions are less common than Down’s Syndrome and often, sadly, lead to miscarriage.
A full karyotype will reveal more detail of the structure of your baby’s chromosomes. But most conditions will be picked up with the PCR, which takes less time.
After 14 long days, I got the confirmation that they had not collected enough cells from my placenta to complete the remainder of the tests. The midwife then offered us an amniocentesis. We had overnight to make a decision and I was to speak to someone at my GTT (Glucose Tolerance Test) the next day.
We decided against further tests, as felt it was just too risky and we had no history of any disabilities with our other children.
I was having a GTT as have a history of Gestational Diabetes, but that is a whole other post!!