Utility is an economic term for a person's overall well-being and satisfaction. Consumers play a role in the economy by maximizing utility, which means allocating their scarce resources, such as limited time or money, most efficiently. Utility maximization is different for every person.
You can start using it right away but it was suggested to us by our midwives to hold off until 6 weeks as pacifier use can mess with their breastfeeding latch (it's a different kind of sucking).
However, pacifier use often is an easier habit to break. If you offer an infant a pacifier, use a clean one. Never dip a pacifier in sugar, honey or other sweeteners before giving it to an infant. Most children stop sucking their thumbs or other fingers on their own between the ages of 2 and 4 years. The behavior lessens gradually