Identifying High-risk Infants
Infants Born Prematurely
Premature birth refers to birth prior to 37 weeks gestational age (GA). As the GA decreases the risks rise for many medical complications that can jeopardize brain development and/or health outcomes which both translate into potentially diminished quality of life and impaired self-care efficacy.[3,4] In brief, the magnitude of health-related problems is inversely proportional not only to GA but also to birth weight. As these drop, morbidity and mortality rise with survival being rarer at the edge of viability nearer to 22 weeks GA.[5–8] Low-birth-weight (LBW) refers to babies born less than 2500 grams and this category is subdivided into very low birth weight (<1500 g) and extremely low birth weight (ELBW; <1000 g).
Over 12,000 preterm infants per year in the United States develop intraventricular hemorrhage (IVH). Premature infants with moderate to severe IVH (grade 3-4) are at high risk for post-hemorrhagic hydrocephalus, cerebral palsy, and mental retardation. It is not uncommon for professionals to report that mild IVH (grade 1-2) has no major sequel; however, some research suggests there is a risk for developmental disabilities. About 45% to 85% of premature infants with moderate-to-severe IVH develop major cognitive deficits and approximately 75% of those will need special education.
Preterm infants less than 36 weeks GA account for 70% to 90% of total necrotizing enterocolitis (NEC) cases often caused by bacterial infection resulting in bowel necrosis. ELBW infants are at greater risk for intestinal perforation or NEC resulting in a nearly 50% mortality or some degree of neurodevelopmental impairment among survivors. The rate of NEC has remained the same over the last 20 years with prolonged hospitalizations and a multitude of complications leading to significant morbidities, for example, parenteral nutrition cholestasis, catheter-related infections, intestinal loss, short bowel syndrome, nutritional deficiency, and growth and developmental delays.
Since the late 1980s, the incidence of retinopathy of prematurity has remained about 20%; however, some studies show a wide variable range of 10% to 84% among lower GA infants.[5–9] Over an 18-year period in Australia, the rate of retinopathy of prematurity in preterm survivors at NICU discharge increased from 78.2% between 1992 to 1997 to 86.1% between 2004 to 2009 and was inversely proportional to GA ranging from close to 90% at 23 to 25 weeks GA and dropping to 76% at 27 weeks GA.
Higher rates of morbidity have been reported in the ELBW infant population (eg, chronic health problems; growth failure; mental retardation; learning difficulties; as well as sensory, motor, and behavioral handicaps. The lower the birth weight, the higher the risk for cerebral palsy (CP), one of the most severe disabilities. Over the past several decades, advances in technological care in the NICU resulted in a rise in sicker and smaller survivors with severe CP. One meta-analysis reported the variation in prevalence of CP among preterm infants born at different GAs as follows: 15% in the 22 to 27 weeks GA group, 6% in the 28 to 31 weeks GA group, 0.7% in the 32 to 36 weeks GA group, and 0.1% among full-term infants. Cognitive outcomes have been associated with a combination of factors including medical variables and caretaker education.[15,16]
NAINR. 2012;12(4):221-226. © 2012 Elsevier Science, Inc.