The pants might shrink by the maximum of 5%. Wash at 40 celsius.
Long-lasting sizing
The sizes are long-lasting and by choosing the size that is closest
to your child´s height it might be a fair size, but at first you can
fold the pant legs. The growth of a child has been considered in the
size range, thus the leggings can be used for longer time even tough the
child is growing.