DESCRIPTION

Neonatal intensive care unit (NICU) graduates who have an increased risk for neurodevelopmental disabilities (NDD) require close follow-up and serial cognitive, sensory, and motor monitoring.

EPIDEMIOLOGY

• In the United States, 18% of births involve some NICU care; admission rates increase with decreasing gestational age (GA).
• Prematurity: In 2022, the U.S. preterm birth rate was 10.4%.
• Hypoxic-ischemic encephalopathy (HIE): 1 to 3/1,000 births should be admitted to the NICU within 6 hours for therapeutic hypothermia.
• Respiratory failure: deficiency of oxygenation with insufficient ventilation; mechanical ventilation required in 18/1,000 births; associated with many comorbidities and up to 15% mortality
• Congenital anomalies (3% of U.S. births) account for 20% infant deaths; most common is congenital heart disease (CHD) in 1%; neural tube defects in 3 to 4/10,000; genetic syndromes (including those with metabolic disorders)

RISK FACTORS

• Prematurity—deficits generally correlate with GA, birth weight (BW); preterm birth associated with injuries to many organ systems due to:
  • Factors that precipitate preterm delivery (infection, inflammation)
  • Physiologic instability after birth
  • Required use of immature organ systems
  • Insufficient endogenous protective factors (thyroxin, cortisol, surfactant)
  • Side effects of treatment
• Brain injury—intraventricular hemorrhage (IVH), HIE, stroke, encephalomalacia, periventricular leukomalacia (PVL), hydrocephalus, seizures
• Congenital/postnatal infections—cytomegalovirus (CMV), herpes simplex virus (HSV), HIV, bacterial sepsis, Zika virus
• Congenital anomalies increase risk for later NDD.
• CHD: higher rates of brain malformations, microcephaly, prolonged hypoxemia with cardiopulmonary bypass/arrest
• Neonatal abstinence syndrome—higher risk with polydrug exposure
• Respiratory failure/chronic lung disease (CLD)/bronchopulmonary dysplasia (BPD)—intermittent hypoxia and acidosis, poor growth
• Intrauterine growth restriction (IUGR)
• Genetic syndromes
• Severe neonatal illness—sepsis, necrotizing enterocolitis (NEC), high-grade retinopathy of prematurity (ROP) (with or without intervention)