The Long-Term Pulmonary Sequelae of Prematurity: The Role of Familial Airway Hyperreactivity and the Respiratory Distress Syndrome

Abstract

Respiratory distress syndrome of the newborn, prematurity, and familial airway hyperreactivity may contribute to long-term pulmonary sequelae. We assessed the role of each by testing pulmonary function and airway reactivity in 11 prematurely born children who survived the respiratory distress syndrome and in 11 prematurely born children who had no neonatal respiratory disease, each of whom was paired with a sibling born at term. The subjects were between 7 and 12 years of age when studied. Airway reactivity was also assessed in their mothers. The group who had had the respiratory distress syndrome had higher ratios of residual volume to total lung capacity and lower values for forced expiratory volume in one second than did their siblings or normal controls (P less than 0.01). Expiratory flow was decreased in both groups born prematurely (P less than 0.02) and was related to neonatal exposure to oxygen (r = -0.71, P less than 0.02). The incidence of airway hyperreactivity was elevated in all groups, including the mothers. These data suggest that long-term pulmonary sequelae of the respiratory distress syndrome of the newborn are related to the disease, its treatment, or both, and to airway hyperreactivity. In prematurely born children without neonatal lung disease, the sequelae are related to airway hyperreactivity. The possibility of a relation between familial airway hyperreactivity and premature birth is suggested.

Low-Normal Gestational Age as a Predictor of Asthma at 6 Years of Age

“…3,5 This study differs in that very premature infants and those requiring mechanical ventilation were not enrolled, which enabled us to observe the association between low-normal gestational age and asthma independent of respiratory distress syndrome and the sequelae of mechanical ventilation. Increased incidences of airway hyperresponsiveness have been observed among mothers who deliver prematurely 3,24 and among siblings of very premature infants.…”

“…The Ponderal index was derived with the following equation: Ponderal index ϭ (birth weight, in grams) ϫ 100/(birth length, in centimeters). 3 To assess the effects of birth weight independent of gestational age, z scores were generated from reference percentiles of birth weight for gestational age for Ͼ6.5 million singleton births, available from the National Center for Health Statistics 1999 and 2000 Natality Data Sets. 18 Beginning when the child was 2 months of age, a telephone questionnaire was administered to the child's primary caregiver every 2 months until the child's second birthday.…”

“…Although it is well established that prematurity is a major risk factor for the development of chronic lung disease, as a result of bronchopulmonary dysplasia, 1,2 and that extremely premature infants more frequently demonstrate persistent airway hyperresponsiveness in early childhood, 3 the influence of less extreme prematurity on the development of asthma among otherwise healthy children remains unresolved. Both low birth weight and prematurity were directly associated with the development of wheeze or asthma in several studies, [4][5][6][7] whereas other studies either failed to demonstrate an association [8][9][10][11] or demonstrated inverse relationships.…”

Risk factors and clinical evolution of asthma in children

“…Bertrand et al 44 compararam crianças com idades entre 7 e 12 anos, nascidas prematuramente e que haviam manifestado síndrome do desconforto respiratório (SDR), com outras, também nascidas prematuramente, porém, sem história de SDR. Verificaram, entre as com SDR, alterações em volumes e fluxos pulmonares e HB, e entre as sem SDR, apenas HB.…”

Risk factors for asthma

“…A prematuridade poderia estar associada com hiperreatividade da musculatura lisa uterina 7 . A doença pulmonar crônica do recém-nascido (displasia broncopulmonar) seria mais grave nas crianças com história de atopia familiar 8 .…”