NHS not using accurate info in the 12 week screening calculation- why?

[YellowLeavess]

I had my 12 week screening test done yesterday and I wondered if what I experienced was standard practice.

First of all - my weight. I was weighed, and the scale showed 3.5lbs more than I actually am. (I weigh myself daily and track it.) The nurses said they do not account for the weight of the clothes etc, and simply wrote that figure down instead. So the data point (my ‘weight’) being used to calculate the trisomy risk is not correct, which will lead to an inaccuracy in the final risk score.

Also, if it’s an IVF pregnancy then they use the age of the woman at the time the egg was collected. This obviously makes sense and is the correct thing to do, as any chromosomal issues are formed at the point of conception.

So for natural pregnancies, why don’t they use the age of the woman at the time she conceived - i.e. the age of the egg, as with IVF pregnancies? Instead, they recorded my age as the age I’ll be at birth. But again, that’s inaccurate and will lead to an error in the final risk score.

Both of these inaccuracies are going to artificially increase my risk profile which is going to cause a greater level of anxiety and stress. Why don’t the NHS want to use the best, most accurate data to input into the risk equation?

I'm with you @YellowLeavess - so many things could be done better. I had 3 scans prior to my 20 weeks scan, all showing a due date of 25 June and tracking dead on one of their lines. 20 weeks scan comes round and they moved it to 23 June, even though all other scans were 25 June. I asked if baby's growth went back to tracking for 25 June, would they update the 20 weeks scan, nope. That would be identified as slow growth. 🤯 That specific reading is apparently more accurate than the other 3 (despite having a scan say 25 June less than a week before). Makes no sense. Midwives measuring the size of your bump is also wildly inaccurate, as different midwives measure slightly differently and there is so much room for human error.

When it comes to birth choices, the latest evidence is also ignored in my trust on how to avoid bad tears. Despite the evidence being clearly there, I wasn't able to have what I asked for and tore badly. They also insist on waiting just 1 minute before clamping the cord, despite the latest evidence saying that is the absolute bare minimum that should be there to allow baby to get all their stem cells.

In my view, unfortunately, the NHS policies around maternity generally are very much out of date and substandard.

I asked how the leap year would affect my due date while the midwife was using her little date calculating wheel.

she looked astonished, and then perplexed, and said no one had ever asked that before and that she didn’t know the answer.

She was the head midwife with more than 20 years experience under her belt. Just seemed a bit odd - presumably deduct a day from the date I was told.

but she wouldn’t and if I had gone over dates they would be using the wrong due date.

Just throwing in something about the weight issue

How often do you calibrate your scales at home because as someone who works in the nhs and uses the scales , we have the outside company coming in every month to recalibrate them

chances are nhs scales will be More accurate than home scales

The minor differences in data in are not going to make any difference in your odds.

If you were 28 years and 11 months old, do you suddenly think that at 29 years old that your chances of trisomy etc. are suddenly increased? No they are not, that’s not how biology works but it’s an average. Odds made from averages and likelihoods are never “good” data, they are estimates and the best that you can give to a wide range of people with a fairly high success rate. You can get an actual positive or negative result from the correct “good” data, if you want to take that route.

As a scientist I guess you know that the only test that will give you an actual result, rather than statistical likelihoods, is an invasive one.

I had a CVS for that very reason. I don't trust statistics.

How old will you be at baby’s birth if you don’t mind me asking?
Ill be 40 at birth and this makes me a high risk pregnancy, I’m being induced a week early on the findings that a woman’s placenta over 40yo doesn’t always work as well as a woman under 39 yo. Maybe this is the same with you.
It’s also an IVF pregnancy and my BMI was slightly over 30 so again adds to the ‘high risk’ theory. I’ve had a perfect pregnancy all the way through but the additional scans/consultations have been a godsend as it’s put my mind at ease.
Trust the system, measuring slightly over your weight or recording birth age, I cant see will do you any harm, enjoy the pregnancy and congratulations :)