30 weeks and growth percentiles dropping

[baconsandwiches]

Hi all, just looking for a bit of advice in case anybody has had something similar.
At our 20 week anomaly scan, abdominal circumference was the 75% percentile and fetal weight was the 45th.
We had another scan at 30 weeks (private, not requested for any medical reason) and abdominal circumference has dropped to 50th percentile and fetal weight the 20th.
The umbilical artery PI measure was 0.77 which is showing right at the lower end (5th percentile or so), with enddiastolic flow showing as positive.

I'm waiting on the hospital to call me to see whether I need to go in, but wondered if anybody had encountered something like this or if it's something to worry about/suggestive of any other problems?
Thanks

The umbilical PI being low resistance is a good thing, the lower the resistance the better, as it is showing a good blood flow through the cord.
What you don't want is high resistance in the cord with absent end diastolic flow, which you do not have.

There is a lot of discrepancy between measurements from one day to another due to fetal position, scan machine, operator etc etc.

You had one scan done privately, so most likely a different machine and who knows the qualifications of the person scanning you (although I am sure they're probably NHS staff working extra).

I wouldn't be very worried with that drop anyway, especially in light of no clinical reasons to worry.

Too many scans cause unnecessary angst, as this has shown.