Thanks for posting your query at DoctorSpring.com
The best way of putting these findings into perspective is actually statistical risk.
Objectivity is better than pedantism in these cases.
Short humerus is a mid level marker, that, if present, raises the risk by 6 folds, and a short femur is a low level marker, that approximately raises the risk by 2.2.
So there are two soft markers , not one.
And a risk of 1 in 28 warrants an amnio, which again, is not essential, if termination is not an issue at all.
Not knowing for sure however, certainly is.
Short of an amnio, nothing can put this into absolute perspective.
Now you are the sole deciders of whether you wish to go ahead with that or not.
I would just state scientifically, that the risk if quite high, and it does warrant an amnio, however if you wish to continue anyway, the risks of an amnio outweight the benefits.
All the best
Please feel free to discuss further,