Neonatology is a subspecialty of pediatrics that consists of the medical care of newborn infants, especially the ill or premature newborn. It is a hospital-based specialty, and is usually practised in neonatal intensive care units (NICUs). The principal patients of neonatologists are newborn infants who are ill or require special medical care due to prematurity, low birth weight, intrauterine growth restriction, congenital malformations (birth defects), sepsis, pulmonary hypoplasia or birth asphyxia. Historical developments Though high infant mortality rates were recognized by the medical community at least as early as the 1860s, advances in modern neonatal intensive care have led to a significant decline in infant mortality in the modern era. This has been achieved through a combination of technological advances, enhanced understanding of newborn physiology, improved sanitation practices, and development of specialized units for neonatal intensive care. Around the mid-19th century, the care of newborns was in its infancy and was led mainly by obstetricians; however, the early 1900s, pediatricians began to assume a more direct role in caring for neonates. The term neonatology was coined by Dr. Alexander Schaffer in 1960. The American Board of Pediatrics established an official sub-board certification for neonatology in 1975. In 1835, the Russian physician Georg von Ruehl developed a rudimentary incubator made from two nestled metal tubs enclosing a layer of warm water. By the mid-1850s, these "warming tubs" were in regular use at the Moscow Foundling Hospital for the support of premature infants. 1857, Jean-Louis-Paul Denuce was the first to publish a description of his own similar incubator design, and was the first physician to describe its utility in the support of premature infants in medical literature. By 1931, Dr. A Robert Bauer added more sophisticated upgrades to the incubator which allowed for humidity control and oxygen delivery in addition to heating capabilities, further contributing to improved survival in newborns. The 1950s brought a rapid escalation in neonatal services with the advent of mechanical ventilation of the newborn, allowing for survival at an increasingly smaller birth weight. In 1952, the anesthesiologist Dr. Virginia Apgar developed the Apgar score, used for standardized assessment of infants immediately upon delivery, to guide further steps in resuscitation if necessary. The first dedicated neonatal intensive care unit (NICU) was established at Yale-Newhaven Hospital in Connecticut in 1965. Prior to the development of the NICU, premature and critically ill infants were attended to in nurseries without specialized resuscitation