Why no tears?

Caroline

Hi ladies, I'm 36+5 and I want to find out how some mommas who have vaginal birth don't get to tear down there? Is there a special thing you do to prevent it or it depends on other factors? Cos I know people who have had big babies yet have no tears and others who have small babies get tears or stitches. Please help me out. I'm freaking out! Thanks. And good luck.