What might spots on newborn babys stomach and chest be?

Missing info: Newborn rashes can vary from simple self resolving issues to signs of worrisome infection. Proper labeling requires a detailed description or direct exam. Size, color, number, location, raised vs flat, texture, etc. are all descriptors that permit assessment.You are welcome to start over so a more specific answer can be offered.

Newborn rashes: There are literally dozens of types of rashes that for the most part are of no concern and will go away on their own. If there was a fever prior to the rash, there may be some concern of what is called a post-viral exanthem. Many of these signal the end of an infection, but the skin lesions in some, of pustular or vesicular, such as varicella, can pass on the virus through the infected blisters.