Login

Secondary Conditions Associated with Prematurity

Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia, or BPD, refers to the chronic respiratory condition which frequently develops in significantly preterm infants who have required ventilatory support. This condition typically presents with chronic respiratory distress, changes in the respiratory tract itself - such as increased airway resistance, pulmonary edema, pulmonary hypertension - persistent supplemental oxygen dependence, and radiographic aberrancies. BPD may develop following respiratory interventions in the premature neonatal period which involve mechanical ventilation and oxygen administration.

In addition to the development of chronic lung disease, infants with BPD may also be affected by problems with growth/nutrition, developmental progression, and cardiovascular functioning. Gastroesophageal reflux is common in preterm infants and presents a risk of chronic aspiration that may aggravate the already existing lung injury of BPD. Bronchopulmonary dysplasia additionally places the infant at risk for problems with neurodevelopment, such as learning disabilities, cerebral palsy, seizure disorders, sensory impairments, and problems with speech production.

Premature infants commonly require respiratory support because their lungs aren't fully developed. This support typically consists of supplemental oxygen therapy, continuous positive airway pressure (CPAP), and/or mechanical ventilation. For infants whose lungs are not yet making surfactant, synthetic surfactant must be administered exogenously, as mechanical ventilation in the absence of adequate surfactant may induce atelectrauma (lung injury from low pressure) from the continuing ventilation of lung tissue with poor surface tension, or volutrauma, from the overextension and rupture of normal lung tissue. Appropriate surfactant therapy typically improves respiratory outcome and decreases incidence of BPD. Clinicians should be aware of the various problems that may present in the infant who has been diagnosed with BPD.

Infants with BPD often go home on supplemental oxygen. The average length of time the oxygen is needed is about three months; however, some infants may require oxygen therapy for up to one year. Infants who sustain BPD have the most problems during the first year of life. Colds and respiratory infections are not uncommon, and children tend to get sicker than unaffected peers. When they do develop a cold or respiratory infection, they require oxygen therapy more frequently. BPD may retard growth in significantly affected infants due to elevated energy requirements from increased respiratory effort. A few babies will continue to have respiratory problems, such as asthma, into adulthood.

The previous material was taken in small part from the Baby Awareness and Support through Interactive Computer Systems (BASICS); a project supported by the U.S. Department of Education and the University of Kentucky.

D'Angio, C.T., & Maniscalco, W.M. (2004). Bronchopulmonary dysplasia in preterm infants: Pathophysiology and management strategies. Pediatric Drugs, 6(5), 303-330.

Eisenberg, J.D. (2000). Chronic respiratory disorders. In R.E. Nickel & L.W. Desch (Eds.), The physician's guide to caring for children with disabilities and chronic conditions (pp. 622-624). Baltimore, Maryland: Paul Brookes Publishing.

Retinopathy of Prematurity (ROP)

Retinopathy of Prematurity, usually referred to as ROP, is a condition which often occurs in infants who are born prematurely. Visual impairments frequently result from significant ROP, with blindness occurring in severe cases. Historically ROP was seen as being the direct result of extensive oxygen therapy in the postnatal period of a preterm infant. It is now known that other factors may also be involved.

Around the fourth month of gestation the retinal blood vessels begin growing from the area of the optic nerve in the back of the eye toward the front of the eye, with vascularization typically complete at birth. The preterm infant's retinal/visual development is interrupted by birth, and the events that follow (oxygen therapy, ventilation, surfactant therapy, etc.) somehow induce changes in the normal pattern of blood vessel growth.

Retinopathy of prematurity involves the proliferation of retinal blood vessels in an abnormal pattern. When the vessel growth stops, this may result in retinal scar formation. Contraction of this retinal scar may actually cause the retina to detach - inducing blindness. ROP represents the most common cause of retinal damage in infants. Infants with ROP are additionally more likely to experience myopia, strabismus, glaucoma, and blindness.

What cause the abnormal growth of blood vessels in ROP is still not completely understood. Extensive postnatal oxygen therapy remains strongly correlated. Premature infants should be evaluated regularly by an ophthalmologist while in the neonatal intensive care unit, and at subsequent visits to the clinician during the first few months of life. Early detection of ROP may permit timely intervention, such as laser cauterization, which may stop disease progression and avoid/reduce retinal detachment.

The previous material was taken in small part from the Baby Awareness and Support through Interactive Computer Systems (BASICS); a project supported by the U.S. Department of Education and the University of Kentucky.

Desch, L.W. (2000). Visual and hearing impairments. In R.E. Nickel & L.W. Desch (Eds.), The physician's guide to caring for children with disabilities and chronic conditions (pp. 269). Baltimore, Maryland: Paul H. Brookes Publishing.

Menacker, S.J. & Batshaw, M.L. (1997). Vision: Our window to the world. In M.L. Batshaw (Ed.), Children with disabilities (pp. 220-221). Baltimore, Maryland: Paul H. Brookes Publishing.

Necrotizing Enterocolitis (NEC)

Necrotizing enterocolitis is a potentially life-threatening condition occurring in approximately 2-5 % of very low birth weight infants. NEC carries an estimated 20% mortality rate. It represents the most frequent gastrointestinal emergency occurring in neonatal intensive care units. The etiology of NEC appears to be related to multiple factors, including preterm delivery, hypoxia, administration of enteral tube feedings, and toxicity to intestinal microorganisms. Of these factors, only prematurity is consistently correlated with the occurrence of NEC. Even though NEC has been recognized as a disease entity for a century, the exact pathogenesis remains unclear.

Infants with necrotizing enterocolitis typically present with abdominal distention, sluggishness, vomiting, and/or abdominal tenderness, which may progress to more severe symptoms of intestinal bleeding or actual perforation if gone unchecked. Most experts agree that NEC develops due to the interaction of three basic factors: premature administration of enteral tube feedings; ischemia of the intestinal wall related to the action of vasoconstrictive substances, such as platelet activating factor (PAF); and inflammatory response to bacterial toxins.

Treatment of NEC within the NICU setting involves the judicious management of enteral tube feeding protocols, nasogastric suctioning to decrease bowel distention, intravenous fluids administration, and often antibiotic prophylaxis. Severely affected cases frequently require surgical resection of the bowel to remove the necrotic tissue. It has been established for some time that breast milk feeding offers some protection against the development of NEC. Such is the importance in high risk infants that donor human milk may be used when the mother is unable to provide needed lactation. Breast milk may additionally be fortified to insure optimal nutrient provision.

Bernbaum, J.C., & Batshaw, M.L. (1997). Born too soon, born too small. In M.L. Batshaw (Ed.), Children with disabilities (pp.126-127). Baltimore, Maryland: Paul H. Brookes Publishing.

Lee, J.S., & Polin, R.A. (2003). Treatment and prevention of necrotizing enterocolitis. Seminars in Neonatology, Dec 8(6), 449-450.

Updegrove, K. (2004). Necrotizing enterocolitis: The evidence for use of human milk in prevention and treatment. Journal of Human Lactation, Aug 20(3), 335-339.

Pellegrini, M., Lagrasta, N., Campos, S.J., Garcia, C., & Marzocca, G. (2004). Necrotizing enterocolitis in the preterm infant: Etiopathogenic considerations. Recent Progress in Medicine (Italian journal), Aug 95(7-8), 384-387.

Intraventricular Hemorrhage (IVH)

Intraventricular hemorrhage refers to bleeding that occurs into the normally fluid-filled spaces of the brain, or ventricles. The term may also be used to describe bleeding which occurs into the brain tissue itself near the ventricles. Preterm infants are at a significant risk for IVH, with infants born most prematurely experiencing the greatest risk. IVH rarely occurs in term infants.

IVH in preterm infants is related to the immaturity of blood vessels in the brain. These vessels may easily rupture, allowing leakage of blood into the surrounding tissue. Additionally, preterm infants often have difficulty regulating blood flow to the brain. Alterations in brain blood volume may further increase the chance of vessel rupture. Typically IVH will occur during the first three days of life. Infants sustaining significant IVH may experience long term effects such as hydrocephalus, learning disabilities, brain injury, seizures, hearing or visual deficits, motor problems, and/or delays in development. Hydrocephalus is the most common clinical complication of IVH.

Intraventricular hemorrhages are graded into four levels according to type, location, and severity of bleed. The majority of IVH's are Grade I or II, and are generally considered "mild". Typically these infants do as well as unaffected infants of similar gestational age. Infants with Grade III and IV have increasing risk of brain injury and subsequent developmental problems. Very low birth weight infants (less than 1000g) and/or infants of 28 weeks or less gestation frequently develop cerebral palsy (as many as 17 %) or other neurodevelopmental sequalae. Long-term effects are most common in babies with Grade IV IVH, and/or those who have developed hydrocephalus requiring treatment.

The previous material was taken in part from the Baby Awareness and Support through Interactive Computer Systems (BASICS); a project supported by the U.S. Department of Education and the University of Kentucky.

Colvin, M., McGuire, W., & Fowlie, P.W. (2004). Neurodevelopmental outcomes after preterm birth. British Medical Journal, 329, 1390-1393. Retrieved online December 23, 2004 from http://bmj.bmjjournals.com/.

Periventricular Leukomalacia (PVL)

Periventricular leukomalacia is a term used to describe the damage and subsequent necrosis which occurs in white matter areas of the brain. Preterm infants are at risk for developing PVL due to both the immaturity of brain structures and blood pressure regulating systems at birth. PVL may occur as a result of either lack of blood flow to the white matter area or by pressure created by ventricles filled with blood. Neurodevelopment may be retarded or altered due to white matter injury. In significant cases of PVL, neurological disorders, including cerebral palsy and/or mental retardation may result. Preterm infants with PVL constitute approximately 35-40% of children with cerebral palsy (Nickel, 2000).

Over fifty percent of children who have incurred some degree of PVL have normal intelligence. However, it is important for the clinician to be alert for signs of developmental and/or cognitive delay, as early intervention will improve outcome.

The above material was taken in part from the Baby Awareness and Support through Interactive Computer Systems (BASICS); a project supported by the U.S. Department of Education and the University of Kentucky.

Nickel, R.E. (2000). Cerebral palsy. In R.E. Nickel & L.W. Desch (Eds.), The physician's guide to caring for children with disabilities and chronic conditions, (pp. 143). Baltimore, MD: Paul H. Brookes Publishing.

Cerebral Palsy: Potential Neurological Complications

Preterm infants, particularly those with birth weights less than 1500g and/or gestational ages of less than 32 weeks, are at risk for delays or deficits in neurodevelopment. Aberrant neuromotor function observed in the first year of life may resolve with maturation (transient dystonias) or evolve into frank cerebral palsy. Cerebral palsy is most strongly associated with white matter injury occurring in very preterm infants who have sustained periventricular leukomalacia (PVL) and/or Grade IV intraventricular hemorrhage. Preterm infants with PVL constitute approximately 35-40% of children with cerebral palsy (Nickel, 2000). Children who do not develop cerebral palsy still may experience motor impairments which may not become evident until they become school age.

Neuromotor disturbances represent the most common hidden disability occurring in children of preterm birth. Additional risk factors for neuromotor dysfunction include: frequent episodes of apnea and bradycardia during the neonatal period; severe bronchopulmonary dysplasia; and male gender. The former two factors may induce hypoxia of the brain tissues. Neurodevelopmental dysfunction is also positively associated with lower cognitive outcome. It is important for the clinician to be alert for signs/symptoms of neurosensory or neuromotor dysfunction, as timely intervention may improve outcome.

Bracewell, M., & Marlow, N. (2002). Patterns of motor disability in very preterm children. Mental Retardation and Developmental Disabilities Research Reviews, 8(4), 241-248.

Colvin, M., McGuire, W., and Fowlie, P.W. (2004). Neurodevelopmental outcomes after preterm birth. British Medical Journal, 329, 1390-1393. Retrieved online 12/23/04 from www.bmj.com.

Janvier, A., Khairy, M., Kokkotis, A., Cormier, C., Messmer, D., & Barrington, K. (2004). Apnea is associated with neurodevelopmental impairment in very low birth weight infants. Journal of Perinatology, 24(12), 763-768. Retrieved online 12/26/04 from PubMed.com

Nickel, R.E. (2000). Cerebral palsy. In R.E. Nickel & L.W. Desch (Eds.), The physician's guide to caring for children with disabilities and chronic conditions, (pp. 143). Baltimore, MD: Paul H. Brookes Publishing

Perlman, J.M. (2001). Neurobehavioral deficits in premature graduates of intensive care: Potential medical and neonatal environmental risk factors. Pediatrics, 108(6), 1339-1346. Retrieved online12/26/04 from www.pediatrics.org.

Intellectual (Cognitive) Disability

Infants born significantly preterm often experience some degree of hypoxia during the perinatal and neonatal periods typically related to respiratory and cardiovascular system immaturity. Hypoxia of brain tissues may result in permanent damage. Additionally, bronchopulmonary dysplasia, intraventricular hemorrhage (with or without hydrocephalus), and/or periventricular leukomalacia may occur in very premature infants and further contribute to destruction of brain tissue. Hypoxia-related injury sustained in the area of the hippocampus and/or basal ganglia may contribute to neurobehavioral deficits as the infant matures. Very sick low birth weight infants frequently have low levels of thyroxine - despite normal thyrotropin levels. Because thyroid hormones are necessary for normal brain development, these infants may be at risk for neurodevelopmental abnormalities, such as lower IQ scores, cerebral palsy, and learning disabilities. Hyperbilirubinemia is also a frequent problem in sick preterm infants and may injure neurons - even when the bilirubin level is not severely elevated. Finally, glucocorticoids (steroids) administered to prevent or treat lung problems in the neonatal period may alter the structure of the developing brain, particularly in the area of the hippocampus.

Perlman, J.M. (2001). Neurobehavioral deficits in premature graduates of intensive care: Potential medical and neonatal environmental risk factors. Pediatrics, 108(6), 1339-1346. Retrieved online12/26/04 from www.pediatrics.org

Short, E.J., et al. (2003). Cognitive and academic consequences of bronchopulmonary dysplasia and very low birth weight: 8 year outcomes. Pediatrics, 112(5), 359-356. Retrieved online 12/26/04 from http://www.pediatrics.org

Yeh, T.F., et al. (2004). Outcomes at school age after postnatal dexamethasone therapy for lung disease of prematurity. New England Journal of Medicine, 350(13), 1304-1313.