Choosing wisely for the other 80%: What we need to know about the more mature newborn and NICU care.

Although neonatal intensive unit (NICU) care is envisioned as the care of very immature infants, more than 95% of births and 80% of NICU admissions are of more mature newborns-infants born at 34 or more weeks' gestation. In spite of the size of this population there are important gaps in the understanding of their needs and optimal management as reflected by remarkably large unexplained variation in their care. The goal of this article is to describe what is known about the more mature, higher birth weight newborn population's use of NICU care and highlight important gaps in knowledge and obstacles to research. Research priorities are identified: including (1) the need for birth population based rather than NICU based studies, and (2) population specific data elements. Summary: More mature newborns-infants of 34 or more weeks' gestation-account for most NICU admissions. There are large gaps in the understanding of their needs and optimal management as reflected by large unexplained variation in their care. We enumerate these gaps in current knowledge and suggest research priorities to address them.