If I hang something to dry in order to minimize shrinking and then later, after many washes, put it in the dryer, will it shrink?

I had to purchase 2 different sized polo's for my school uniform since I am expecting and wasn't sure how big I would get. I was told they shrink A LOT if you dry them, so I want to hang dry them now, but was hoping I could shrink them postpartum (so I didn't have to purchase new uniforms next semester). Is that even possible?