A lot of minor heart defects or holes close on their own.
Not very if it is minor. My first baby had one too. They can't see a lot at 20wks so they had to rescan again after 24wks. They then kept on eye on it and after delivery our peadiatrician sent baby for a heart scan and they measured it and said it was fine and they usually resolve themselves as baby grows. We're not booked for another scan until he is 3yrs just too make sure its closed. Its got nothing to do with anything I did, most likely hereditary, and if its classified as minor the baby wont even notice. I hope this is helpful and gives you some peace of mind! Good luck!