For parents of premature babies, admission of their baby into a Neonatal Intensive Care Unit (NICU) can be overwhelming and unfamiliar. Neonatologists emphasize that understanding how the NICU works, its history, structure, and levels of care can help families better navigate this critical phase of newborn care.
Modern neonatal intensive care traces its roots to the mid-20th century. One of the most widely recognized pioneers was Dr. Mildred T. Stahlman, a U.S. neonatologist who established one of the first organized NICUs in the 1960s at Vanderbilt University. Her work demonstrated that premature and critically ill newborns could survive with specialized respiratory support, temperature regulation, and continuous monitoring.
Before the NICU model, premature infants were often cared for in general nurseries with limited technology. The development of incubators, mechanical ventilation, and neonatal-specific nursing transformed survival outcomes for preterm infants and laid the foundation for modern neonatology.
Since their inception, NICUs have evolved rapidly alongside advances in medical science. Early units focused primarily on warmth and oxygen delivery. Today’s NICUs integrate advanced respiratory support, precise nutritional strategies, infection control protocols, and neurodevelopmental care.
Key milestones in NICU evolution include:
Introduction of surfactant therapy for premature lungs
Development of non-invasive ventilation techniques
Improved monitoring of brain activity, oxygen levels, and heart function
Family-centered care models that involve parents in daily care
These advances have significantly improved survival rates and long-term outcomes for preterm infants.
A modern NICU is a highly specialized unit designed to support newborns who are born prematurely, have low birth weight, or experience medical complications at birth. According to neonatologists, NICUs typically provide:
Continuous cardiorespiratory and oxygen monitoring
Temperature-controlled incubators or radiant warmers
Respiratory support, including CPAP and mechanical ventilation
Specialized nutrition via intravenous lines or feeding tubes
Infection prevention and antimicrobial management
Developmental care to protect the brain, vision, and hearing
Each baby’s care plan is individualized and adjusted as the infant grows and stabilizes.
Premature infants often require specialized support because their organs are still developing. Common areas of care include:
Respiratory support due to immature lungs
Feeding assistance until coordination of sucking and swallowing matures
Thermoregulation to maintain stable body temperature
Infection surveillance, as immune systems are underdeveloped
Neurological monitoring to support brain development
Neonatologists stress that many of these challenges are expected and managed routinely in NICUs worldwide.
MedBound Times contacted Dr. Munish Kumar Raizada, MD, FAAP, US board certified Neonatologist to know about the inside of the NICU in detail.
Can you explain the types or levels of care that premature babies are placed into in the NICU? How do neonatologists decide what level of NICU care a baby needs, and can that level change over time?
Dr. Munish Kumar: The Neonatal Intensive Care Unit (NICU) is designed to care for neonates, infants in the first 28 days of life though babies admitted during this period may remain hospitalized for several weeks or even months, particularly if born prematurely. In the United States, NICU care is structured into levels based on complexity.
NICUs are organized into levels of care based on the complexity of medical services provided:
Provides basic neonatal care for healthy or near-term infants who require minimal support.
Level II cares for moderately ill infants, typically those born after 32 weeks’ gestation or those needing short-term respiratory or feeding support.
Offers comprehensive care for very premature or critically ill infants, including advanced ventilation, surgical support and imaging.
Provides the highest level of care, including complex surgeries and management of rare or severe conditions, including ECMO.
Babies may move between levels as their condition improves, a process neonatologists describe as a sign of progress rather than concern.
These designations exist to standardize protocols and define what types of conditions each unit is equipped to manage. A baby’s level of care is determined by gestational age, birth weight, organ maturity, and medical complications.
These levels are standardized to guide hospital protocols, staffing requirements, and the range of conditions a unit is authorized to manage. NICUs treat a wide spectrum of neonatal conditions, from relatively common issues such as neonatal jaundice requiring phototherapy to life-threatening disorders including respiratory distress syndrome (also known as hyaline membrane disease), birth asphyxia, sepsis, necrotizing enterocolitis, pneumothorax, pneumonia, and congenital anomalies such as congenital diaphragmatic hernia, gastroschisis, and omphalocele.
Many Level III units can also manage complex cardiac conditions, both cyanotic and acyanotic, including ventricular septal defects and patent ductus arteriosus, with some cardiac procedures performed bedside in collaboration with pediatric cardiac surgeons.
Importantly, a baby’s NICU level can change over time. As an infant stabilizes or improves, they may be transferred from a higher-level NICU to a lower-level unit closer to home, or conversely, moved to a higher-level unit if complications arise.
What are the most common medical challenges premature babies face in the NICU, and which of these typically resolve before discharge?
Dr. Munish Kumar: Premature infants face a wide range of medical challenges, most commonly related to immature organ systems. Respiratory problems are among the most frequent, including respiratory distress syndrome (RDS), transient tachypnea of the newborn, and the need for ventilatory support. They often require prolonged respiratory support through nasal cannula, CPAP, or mechanical ventilation.
Temperature instability, feeding difficulties, metabolic imbalances such as low calcium or sodium levels, infections due to immature immunity, and neonatal jaundice are also common. For this, temperature regulation using incubators or radiant warmers is required.
Nutritional management is critical, as very preterm infants may not tolerate enteral feeding and therefore require total parenteral nutrition (TPN). Metabolic disturbances, infections due to immature immune systems, and conditions such as neonatal jaundice are common and require close monitoring.
Many of these issues improve as the baby grows and matures. Conditions like jaundice, feeding immaturity, and mild respiratory distress often resolve before discharge.
Modern NICU care is inherently multidisciplinary. In addition to neonatologists, advanced neonatal nurse practitioners, pediatric surgeons, cardiologists, dietitians, pharmacists, physical and occupational therapists, and social workers all play essential roles.
Parental involvement is considered a core component of neonatal care. Many NICUs allow parents, particularly mothers, 24-hour access to their infants, encourage bedside interaction even when kangaroo care is not yet possible, and ensure families are informed about ongoing treatments and progress.
However, babies with more complex conditions, such as severe prematurity, prolonged oxygen dependence, or surgical needs may require longer hospitalization and ongoing follow-up after discharge.
How can parents safely participate in their baby’s care while the infant is in the NICU, and why is this involvement important?
Dr. Munish Kumar: Parental involvement is an essential part of neonatal care. Most NICUs encourage parents to visit frequently and participate in their baby’s care under guidance from nurses and medical staff. Even when a baby is too fragile for skin-to-skin contact, parents can touch their baby, sit at the bedside, and observe daily care routines.
Many NICUs allow mothers 24-hour access, including nighttime visits, to promote bonding and reduce anxiety. Involvement helps parents understand their baby’s condition, builds confidence in caregiving, and supports long-term emotional bonding. Open communication between families and the care team ensures parents are informed about treatments, nutrition, and medical progress.
What signs do neonatologists look for to determine when a premature baby is ready to leave the NICU?
Dr. Munish Kumar: Discharge readiness is based on several key milestones. The baby must be able to maintain body temperature without external support, feed entirely by mouth, and demonstrate consistent weight gain. Most premature infants are not discharged before 35 weeks’ corrected gestational age.
Additionally, infants must pass a car seat challenge test, which evaluates their ability to maintain breathing and oxygen levels while seated. Standard screenings such as hearing tests and newborn metabolic screening must be completed, and vaccinations are initiated. Social factors are also assessed, and social work clearance may be required to ensure a safe home environment. Parents must feel confident and prepared to care for the baby at home before discharge is finalized.
After NICU discharge, what types of follow-up care or developmental monitoring do premature babies usually require at home?
Dr. Munish Kumar: After discharge, routine medical care is typically managed by a pediatrician, who oversees vaccinations, growth, and general health. Babies who experienced complex NICU courses such as extreme prematurity, prolonged oxygen therapy, or surgical interventions may also be followed in high-risk neonatal clinics.
These clinics focus on neurodevelopmental monitoring and assess motor skills, growth, feeding, and cognitive development at regular intervals. The goal is early identification of any developmental delays and timely intervention, ensuring the best possible long-term outcomes for the child.
Neonatologists emphasize that the NICU is a highly specialized environment designed to give premature babies the best possible start. Understanding its history, structure, and care processes can help parents navigate a challenging but often temporary chapter in their child’s life with greater clarity.
