How do birth rates and death rates change as a country moves from being a developing nation to a fully developed industrial economy?

Development decreases the Death Rate in some ways and increases it in others

Development usually means more money for medical care, better nutrition, better clothing and shelter, better awareness of potentially harmful things like home remedies and superstition .But it can also bring more vehicular traffic, thus, more accidents. It can create overcrowded cities and the proverbial "rat race"