I also have 2.3mm (result 1:2xxx) and see some people said high risk, I asked the doctor whether it is too thick and he said it depends on the fetues size. My size at that time was over 7cm and it is normal to be thicker than those in 11 week.
If you can see the nasal bone, the risk is lower.
One advantage of PWH is you know the ratio after 1 hour and no need to worry so long.
I have read some paper after I think the result is high. If the blood result of the two hormones is around 1MoM, it should be ok.
Don't worry too much at the moment.
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3.36 born 3.4kg
15 days 3.85kg
4.79 1 month 4.65kg
5.97 2 months 6.12kg (height 59.5cm)
6.75 4 months 7.94kg (height 65 cm)
6.5 months 8.9kg
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15 week 6 144g 20 week 5 404g
22 week 6 540g 26 week 6 1111g
28 week 2 1364g
7 week 0.66cm 8 week 6 2.06cm
9 week 6 3.03cm 12 week 6 7.05cm