Femur length 31mm at 20 week scan?

[MaisyMay]

We had our 20 week scan and all looked well except that baby's femur length was shorter than average at 31mm. I knew something was off because he took a couple of measurements of it and said 'we always take two measurements to check for accuracy'. The sonographer said it's nothing to worry about and still on the normal scale, but my ds was always measuring above average and dh and I are fairly tall. I'm really worried something is wrong. I read it can be a soft marker for ds or dwarfism althoughlike I said it's still on the normal scale (off of average by 2mm) I was 20+2 at the time of the scan. Does anyone have any experience of this?

 

[Kezzybear]

I'm a sonographer Hun, that measurement is fine. 2mm difference is so tiny and probably just the angle of the measurement. We only worry about femur length being two small if it measures 2 weeks or more less than your dates. (Ie 18 weeks or less if you are 20 weeks)
It's all fine xx

 

[MaisyMay]

Thank you so much Kezzybear, that really reassuring

 

[Kezzybear]

No problems lovely! Any questions just shoot me a message. Enjoy your little growing bundle! Xx

 

[Dwee]

Mine's femur length was 30mm at 20 week scan :/

 

[Kezzybear]

Mine's femur length was 30mm at 20 week scan :/

This is still within normal range. The femur is something that is easy to foreshorten when you are measuring due to angle. It's fine!

 

[MaisyMay]

Thanks again Kezzybear

 

[Kezzybear]

No worries xxx