Hi all I had my 20 week scan a few weeks ago and baby was measuring 7th % for femur length. Went back for a second scan at 22 weeks to check some things that had been missed and baby is now measuring <5% for femur length! All other measurements are bang on 'average'. Femurs are measuring about 5mm under the average currently. Should I be worried? I've read this could be a marker for downs? Any advice appreciated.