The Nuchal Scan...
There should be kettle drums beating ominously at this point.
I've said we were a bit nervous even though the odds were massively against them detecting any problems. The rational parts of our brains know that it is ridiculous to get all flustered about a 1 in 900 chance of there being a chromosomal abnormality with our foetus. The rational parts of our brains know this. Unfortunately, they don't always get to drive. And there's something else. We know that someone gets to be that one person in however many that is unlucky. K___'s grandparents for one. Grandma wasn't old; about 30, but she had a Downs Syndrome kid. My friend S___ has left a message right back near the start of the blog to say she's been told she's high risk. So we know that just because only one person in a sesquigodzillaandgodzukillion draws that short straw, it doesn't mean it can't be you.
Today's test was at a private clinic on Harley Street, called the Fetal Medical Centre, run by a Professor Nicolaides, who K___ confidently informs me is da man for all this kind of stuff and regularly appears on the idiot's lantern. I say it's a private clinic, it's not. It's actually a research foundation and all profits go towards the research they do. It's amazing that people are forever running down the NHS because of their queues when today proved that even when you're paying for it, you can still be kept waiting for over an hour.
We were there to get various tests done. Together these will give a very good indication of whether there is a chance of Downs Syndrome. Here, cribbed from their website, is a basic overview of what we were to have done. The nuchal scan is an ultrasound much like the one we had at the hospital, but much higher quality. They look to see whether there is a nasal bone (75% of babies scanned at about 13 weeks that were found not to have a nasal bone were born with Downs) and the translucency of a fold at the back of the neck called the 'nuchal fold'. The higher the rating, the more likely Downs Syndrome is.
Before this they take blood for testing. They managed to take the bloods almost on time. Although K___ is not fond of needles, as I detailed on Day 85, today she decided it was more important that I retain our seats, so I stayed outside whilst she disappeared off to get what she later claimed was 'another armful' removed. The machine for doing all the magic with the blood is there in the room and they get the blood tests ready to combine with your overall results from the scan. With the blood, they're measuring two hormones (free ß-hCG and PAPP-A). In pregnancies affected by Downs they'd expect to see the levels of free ß-hCG to be increased and PAPP-A to be decreased.
By combining the results of the scan and the nuchal, plus adding in factors they know about the incidence of Downs and how it increases with the mother's age, they have a prediction rate of about 90%. To be absolutely certain, you'd need to have the invasive amniocentesis or chorionic villus sampling, which comes with that 1% chance of miscarriage, discussed previously in the blog.
Once K___ returned with a very clumsily-applied looking bandage in the crook of her elbow, we just had to wait for them to get through the backlog of scans. And wait... If I were playing the text-only adventure game The Hobbit, I'd just type 'Wait' and the computer would respond with 'Time passes'. If bloody only.
Eventually it was our turn. However, I think that may be for another post...
There should be kettle drums beating ominously at this point.
I've said we were a bit nervous even though the odds were massively against them detecting any problems. The rational parts of our brains know that it is ridiculous to get all flustered about a 1 in 900 chance of there being a chromosomal abnormality with our foetus. The rational parts of our brains know this. Unfortunately, they don't always get to drive. And there's something else. We know that someone gets to be that one person in however many that is unlucky. K___'s grandparents for one. Grandma wasn't old; about 30, but she had a Downs Syndrome kid. My friend S___ has left a message right back near the start of the blog to say she's been told she's high risk. So we know that just because only one person in a sesquigodzillaandgodzukillion draws that short straw, it doesn't mean it can't be you.
Today's test was at a private clinic on Harley Street, called the Fetal Medical Centre, run by a Professor Nicolaides, who K___ confidently informs me is da man for all this kind of stuff and regularly appears on the idiot's lantern. I say it's a private clinic, it's not. It's actually a research foundation and all profits go towards the research they do. It's amazing that people are forever running down the NHS because of their queues when today proved that even when you're paying for it, you can still be kept waiting for over an hour.
We were there to get various tests done. Together these will give a very good indication of whether there is a chance of Downs Syndrome. Here, cribbed from their website, is a basic overview of what we were to have done. The nuchal scan is an ultrasound much like the one we had at the hospital, but much higher quality. They look to see whether there is a nasal bone (75% of babies scanned at about 13 weeks that were found not to have a nasal bone were born with Downs) and the translucency of a fold at the back of the neck called the 'nuchal fold'. The higher the rating, the more likely Downs Syndrome is.
Before this they take blood for testing. They managed to take the bloods almost on time. Although K___ is not fond of needles, as I detailed on Day 85, today she decided it was more important that I retain our seats, so I stayed outside whilst she disappeared off to get what she later claimed was 'another armful' removed. The machine for doing all the magic with the blood is there in the room and they get the blood tests ready to combine with your overall results from the scan. With the blood, they're measuring two hormones (free ß-hCG and PAPP-A). In pregnancies affected by Downs they'd expect to see the levels of free ß-hCG to be increased and PAPP-A to be decreased.
By combining the results of the scan and the nuchal, plus adding in factors they know about the incidence of Downs and how it increases with the mother's age, they have a prediction rate of about 90%. To be absolutely certain, you'd need to have the invasive amniocentesis or chorionic villus sampling, which comes with that 1% chance of miscarriage, discussed previously in the blog.
Once K___ returned with a very clumsily-applied looking bandage in the crook of her elbow, we just had to wait for them to get through the backlog of scans. And wait... If I were playing the text-only adventure game The Hobbit, I'd just type 'Wait' and the computer would respond with 'Time passes'. If bloody only.
Eventually it was our turn. However, I think that may be for another post...
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