Why is it that all the DSes Pyjama bottoms seem to shrink

[saltire]

I don't tumble dry them, wash them at 30/40 degrees. yet every single pair they got for christmas - which were full length on Christmas day are now really short. Far shorter than if it was just a growth spurt from teh DSes.
Does this happen to all PJ's then?

I find Ds's pj tops go out of shape very very quickly. I wash at 30 and don't tumble them either

Cest la Vie I think

hmmm- i thought my children were just growing at an astonishing pace......