Small measurement at 20 week scan…dates wrong?

[STSJ90]

Hi everyone,

First time Mum needing some reassurance or advice.

so I went for my 20 week scan today. I’m dated as exactly 20+0. At the scan the femur measurement is small 7% percentile. All other measurements between 34% and 50% so not a big baby generally but the femur worried me. Anyway after a lot of googling I checked the chart and if I were 19 weeks this measurement would be 50% + percentile.

At my initial 12 week scan I was sent away as I was actually only 11 weeks. I know the exact day I conceived as I was using the Mira test, my partner works away which left 1 day of the fertile window for us to conceive. There is no way my calculation can not be correct, the week before I was actually also on my period. Based on my calculations I am actually 19+3 meaning my measurements are much more healthy and make more sense considering my partners height 6’3 and broad (we’re having a boy). Is it possible that my calculation is actually accurate as opposed to the saying scan?

all this is so confusing! Thank you. X

So sorry for your anxiety OP. Did the doctor say if you should worry or not about it? Usually they say things will get to normal on the way.

Our 2nd trimester scan also showed a bit of an issue in one of the lungs, but Dr assured us it should resolve on its own until birth. I'm still going for a heart check to make sure. Did you get any recommendations or are you considering to double check?

Hi,

it was a bit strange really, the sonographer kind of made a joke about it, which I’m sure she did not do with any bad intention saying he will have short legs so he will have to be a ‘confident’ child, probably not the most reassuring thing to say. She didn’t flag it as a concern. It was only when I looked at the report I noticed how out of proportion the femur was with everything else but not enough for them to call me back if that makes sense.

I went for a private scan at 16 weeks and everything was in proportion. Since the scan the femur has grown 10mm which apparently is within the normal range so I’m confused how it can be so different in terms of percentile and proportionality. I’m going to book another private scan for 24 weeks to see what’s going on. I kind of think it may be a misread as she was struggling to get his legs as he kept kicking them around!

Im glad in the position to be able to afford private scans as if I was not I think the position I’ve been left in isn’t great and I can only imagine the anxiety it would cause an expectant mother if she was unable to get a second opinion.

I hope the lung issue isn’t any significant, I’m sure these scans cause us more worry than reassurance!