Body hair loss?

I noticed with my first pregnancy that I was losing really small patches of hair on my forearms and that when I shaved my legs my hair would take longer to grow back. Now after my 3rd pregnancy I have a stray hair here and there on my arms and legs. While it’s great bc I don’t have to shave as much (underarms and bikini area are not affected) I’m curious as to why my arms and legs are essentially hairless and if this has happened to anyone else?