Wrong gestation and EDD on fetal med report?

[Lou5290]

Has anyone had this happen before- I’m not sure if I’m being a bit stupid or if maybe the report is wrong?…

I’m 22 weeks and 3 days pregnant and had an extra anatomy scan today at a bigger hospital due to a dilated kidney that was picked up at the 20 week scan at our local hospital. Good news is that the kidney has corrected itself. However the centiles for measurements of the bones like femur suddenly seem really small (15th previously down to 6th today) and based on that they’ve asked me to come back in 4 weeks to check all is growing ok.

However, on the train on the way home I noticed that the gestation they’ve calculated all the centiles on is 3 days ahead of my actual gestation (which was calculated at at dating scan and has been the same the whole way along so far). Also the EDD has crept forwards 3 days. Can gestational date and EDD change without any discussion, or does it seem like it could be human error on the chart? The midwife was manually entering figures on the computer during the scan as it was at a new hospital. The fetal medicine doctor was also telling me at the beginning of the appointment that the crown-rump measurement that they do early on at the dating scan is the most accurate way to date a pregnancy, so it seems weird that they would change it by 3 days today without mentioning it to me?

If the dates have been entered wrong then the centiles would actually be quite a bit higher and more in line with what they’ve been so far, and probably wouldn’t warrant further monitoring (although would quite like another scan for my sanity at this point!).

Sorry this has ended up being such a long post, any advice/ similar experiences would be much appreciated, would quite like to me able to sleep tonight! Will phone the midwives tomorrow for some clarity :)

It's not normal for the edd to change. Can't hurt to ask them to double-check, mistakes can happen.

Sounds like an error to me. I would ring them in the morning and ask them to change it and redo the report to see how its looking then. Hopefully all well and no concerns when the new measurements are calculated.

None of these things are accurate to within a week anyway. Dating is done from first day of last period, but there is no way of knowing how long after that conception actually happened

I work in screening/ fetal med. It would be very, very unusual for them to change your gestation and EDD from the calculation at your dating scsn. The only time I can think of it happening was when a woman had told us her pregnancy was a natural conception, so we calculated her dates based on CRL, and she later told us it was it was actually IVF and she knew the date of implantation. She hadn't wanted to tell us initially because her MIL was with her and didn't know!

As @Lemniscate8 says, the dates aren't super accurate in any case. But it's important that they're consistent, for the purposes of comparison - as you've discovered!

I would contact the fetal medicine unit and let them know the mistake, and make sure the scan reports are updated in both the digital and printed versions, with the EDD that was calculated at your dating scan.

Thank you so much everyone for your replies! The midwife rang me early this morning as she’d spotted the error and sent over a new report. Things are growing fine compared to the last scan thank goodness, I was starting to worry! Thanks again 😊