Neonates

Neonates are human infants in the first 28 days after birth. This period is characterized by rapid physiological transition from intrauterine to extrauterine life and is a critical window for survival, growth, and development. Definitions may vary slightly, but the term commonly refers to the newborn phase from birth through the end of the first month.

After birth, the neonate undergoes several essential adaptations. Breathing begins or stabilizes, with oxygen uptake shifting from placental to pulmonary circulation. Fetal circulatory shunts, such as the foramen ovale and ductus arteriosus, progressively close in response to rising oxygen levels. The infant also relies on thermoregulation, glucose management, and initiation of feeding. Skin-to-skin contact, warming, and early feeding support these processes and reduce complications.

Clinical assessment and routine care include continuous monitoring of vital signs, measurement of weight, length, and head circumference, and evaluation of feeding and hydration. Newborn screening programs commonly test for metabolic, genetic, and other conditions, often with results available within days. Additional services such as hearing screening and immunizations (including vaccination against hepatitis B at birth in many jurisdictions) are standard components of neonatal care.

Common issues seen in the neonatal period include respiratory distress, particularly in preterm or compromised infants; jaundice due to elevated bilirubin; hypoglycemia or dehydration; infections; and congenital anomalies. Neonatal intensive care follows for high-risk cases, while many healthy neonates are managed with routine observation, prompt feeding, and parental education.

Discharge typically occurs once the infant demonstrates stable temperature, adequate intake, weight gain or controlled weight loss, and reliable caregiver support, with scheduled follow-up to monitor growth and development.