Femur length at 19 weeks- should I be worried?

[poppyseed1663]

Hello,
I’ve just had my 19 week scan and all seems to have gone well. Sonography said that the baby was fine all normal. All her percentiles we around the 50% mark except her femur length, which was at the 11 percentile. I am just a bit worried that this could be a sign of growth problems or Down Syndrome? I have been booked in for a 28 week scan to check growth rates but I’m now panicking a bit. Does anyone have any advice?

Many thanks

I had the same thing; head circumference and abdomen circumference were on 80th/>98th(!) centiles and femur length was on the 17th. Baby arrived perfectly in proportion, with a head on the 50th centiles and everything else on the 25th. The growth scans are often completely inaccurate; it can be very difficult for them to get measurements depending on the baby's position. Easier said than done, I know, but try not to worry too much!

Thank you for that reassurance. The sonographer did not seem worried but I can’t help but be a little anxious!

We had the opposite - got told her legs were 99th centile and therefore that she was really heavy. DP and I both have quite short legs so we were v surprised. Turned out the sonographer had just measured them wrong as they were 50th after all. If you think about it, the baby could have them pulled up or be in an awkward position and when you are measuring something so small even a mm or 2 makes a massive difference. Plus babies do grow at different rates.

If the sonographer wasn't worried then you don't need to - but if it bothers you, then you could ask for another scan in a couple of weeks or have a private scan to see if they are the same/have grown.

Sounds similar to our scan, everything else measuring around 50th-60th centiles and the femur measured on the 7th. After remeasuring a few times the sonographer said it was actually 17th centile (shows you how easy it is to change the measurements depending on who is doing the scan). She wasn't concerned and we weren't referred, but I worried myself sick over it and ended up paying for a private growth scan at 29 weeks. Her femurs had completely caught up by this point and were measuring bang on track with everything else. She was born earlier this month and is completely healthy.

So my advice is try not to worry (I know, impossible!) and step away from Dr Google!

Scans can be very inaccurate so as long as everything is within normal centile range there’s no cause for concern. My dd1 had a smaller head circumference and femur length and a large abdominal circumference at 20 week scan - sonographer didn’t mention but I was worrying it was a sign of gestational diabetes. It wasn’t and my dd1 was born with head on 99.6th centile, Weight 50th and length 75th - scan fairly inaccurate on proportions!

Hi I had this femur was 5th centile despite everything else being 50th or more. I ended up having growth scans every 4 weeks and femur stayed on 5th each time. I worried quite a lot about this throughout pregnancy mainly because no one really told me what this could mean so googled a lot. Dd is almost 3 months and now looking too long for her 0-3 month baby gros!
Stay away from Google is my advice hard I know and I am sure everything will be fine

Try not to worry!! From 27 weeks I had scans every 2 weeks as DS femur was messing very small compared to the rest of him... he was born perfect at 7lb6oz and was actually rather long 😂

Thank you very much for you kind reassurances. It is so hard not to worry but I will try to keep away from Dr Google until my 28 week scan.Fingers crosses she will have a growth spurt!

Thanks again