Risk Factors For Chronic Lung Disease Research Articles

Fetal Growth Restriction Is Worse than Extreme Prematurity for the Developing Lung

Background: Perinatal lung growth is highly vulnerable to inflammation and intrauterine growth restriction (IUGR), two major risk factors for chronic lung disease (CLD) in preterm neonates. However, the balance between extremely low gestational age (ELGA) and IUGR in very preterm infants as risk factors for CLD and co-morbidities remains poorly explored. Objectives: This single-center study aims to compare neonatal morbidity (including CLD) and mortality among ELGA infants with normal birth weight (ELGA-AGA), very preterm infants with IUGR <3rd percentile (VLGA-IUGR) and very preterm infants with a birth weight appropriate for gestational age (VLGA-AGA), matched with VLGA-IUGR infants. Methods: Selected characteristics of the perinatal and neonatal periods were recorded and retrospectively compared among the three groups. Infants with major congenital anomalies were excluded. The diagnosis of CLD was based on whether the infant was receiving supplemental oxygen and/or non-invasive ventilation at a postmenstrual age of 36 weeks. Results: We found that, despite a median difference of 3 weeks in gestational age at birth between VLGA-IUGR and ELGA-AGA infants, neonatal mortality was 35% higher in neonates who had experienced fetal growth restriction, and that VLGA- IUGR was five times more predictive of CLD than was ELGA-AGA. These differences persisted after adjustment for confounding factors such as antenatal steroids, gender and respiratory distress syndrome. Conclusions: This study reports that VLGA-IUGR infants are at higher risk of neonatal mortality and CLD than both ELGA-AGA and VLGA-AGA infants.

Certain type of chronic lung disease of newborns is associated with Ureaplasma urealyticum infection in utero

Recent studies of chronic lung disease (CLD) of newborns emphasize the contribution of antenatal infection. However, the association of Ureaplasma urealyticum infection and CLD has been controversial. The purpose of the present paper was to determine whether U. urealyticum is associated with chorioamnionitis (CAM) and a certain type of CLD. One hundred and five infants <32 weeks of gestation who were admitted to the neonatal intensive care unit at Jichi Medical School Hospital, who underwent both histological and microbiological examinations and who survived to discharge were included. CAM was determined by histological examination. Placenta, gastric and tracheal aspirates, and nasopharyngeal swabs were cultured for Mycoplasma and other microorganisms. CLD was defined as oxygen needed at 28 days of age with symptoms of persistent respiratory distress and hazy or emphysematous and fibrous appearance upon X-ray. CLD was further divided into two subtypes according to the presence of antenatal infection. CAM was associated with premature rupture of membrane (odds ratio [OR], 10.19; 95% confidence interval [CI]: 3.10-33.56), placental colonization of U. urealyticum (OR 6.73, 95%CI: 1.89-23.91), neonatal colonization of other microorganisms (OR 7.33, 95%CI: 1.22-44.13) and level of IgM (OR 1.06, 95%CI: 1.01-1.11). Comparisons between CLD and non-CLD patients showed that gestational age (OR 0.43, 95%CI: 0.30-0.61) and white blood cell count (WBC) at birth (OR 1.06, 95%CI: 1.01-1.11) were risk factors for CLD, while gestational age (OR 0.38, 95%CI: 0.23-0.64), neonatal colonization of U. urealyticum (OR 5.98, 95%CI: 1.17-30.6) and WBC (OR 1.08, 95%CI: 1.01-1.15) were independent risk factors for infection-related CLD compared with non-CLD. Within CLD, infection-related CLD was associated with neonatal colonization of U. urealyticum (OR 43.7, 95%CI: 2.84-673.8) and WBC (OR 1.27, 95%CI: 1.07-1.50). Placental colonization of U. urealyticum was significantly related to CAM; and neonatal colonization of U. urealyticum and leukocytosis at birth were risk factors for infection-related CLD.

Placental and other perinatal risk factors for chronic lung disease in very low birth weight infants.

To clarify the relationship between chorioamnionitis and chronic lung disease (CLD) in very low birth weight (VLBW) infants, we performed a retrospective cohort study of all inborn patients between 1995-1997 with gestational age (GA) less than 32 wk, birth weight less than 1.5 kg, survival to 36 wk adjusted GA, and placentas submitted to pathology (n = 371). Racial distribution as defined by the mother was 40% white/60% nonwhite. Prevalence of CLD, defined as O(2) dependence at 36 wk adjusted GA, was 30%. In a preliminary analysis GA and birth weight for GA (standard deviations from the mean, Z-score), considered together, were inversely related to CLD. After adjustment for GA and Z-score, other risk factors for CLD were white race, acute respiratory distress, pulmonary air leak, patent ductus arteriosus, and septicemia. Two placental lesions were inversely related to CLD: histologic chorioamnionitis and acute atherosis (a placental indicator of preeclampsia). Following multivariate analysis, independent risk factors for CLD were GA (OR, 0.6; 95% CI = 0.5, 0.7), birthweight for GA (OR, 0.4; 95% CI = 0.3, 0.6), white race (OR, 1.9; 95% CI = 1.0, 3.3), patent ductus arteriosus (OR, 2.0; 95% CI = 1.0, 3.5), and pulmonary air leak (OR, 3.0; 95% CI = 1.3, 7.1). Acute atherosis was inversely related to CLD (OR, 0.2; 95% CI = 0.1, 0.8). Chorioamnionitis was stratified by subtype and again no association with CLD was seen in the population as a whole. Finally, chorioamnionitis of all subtypes tended to be increased in white infants and decreased in black infants with CLD. This dichotomy was not explained by differences in death rates, acute respiratory distress, intubation on d 2 of life, or total duration of assisted ventilation. We conclude that while chorioamnionitis was not a risk factor for CLD in our total population, racial differences in its relationship to CLD are worthy of further study.

Chorioamnionitis, mechanical ventilation, and postnatal sepsis as modulators of chronic lung disease in preterm infants

Objective: This case-control study of chronic lung disease (CLD) evaluated the hypothesis that chorioamnionitis promotes CLD and interacts with other risk factors for CLD, including mechanical ventilation and postnatal infection. Study design: We identified a population of 193 infants who met our case criteria for CLD whose birth weights were ≤1500 g. These infants were matched 1:1 with control infants for gestational age and hospital of birth. Results: Univariable analyses revealed decreased CLD risk associated with histologic chorioamnionitis and increased risk associated with mechanical ventilation >7 days and culture-documented sepsis. In multivariable analyses, infants were at greatest risk for CLD when they had exposure to both chorioamnionitis and either mechanical ventilation >7 days (odds ratio, 3.2; 95% confidence interval, 0.9-11) or postnatal infection (odds ratio, 2.9; 95% confidence interval, 1.1-7.4). Conclusions: We conclude that prolonged mechanical ventilation or postnatal infection increases the risk of CLD among surviving preterm infants and that these 2 factors interact with antenatal infection to further increase the risk of CLD. (J Pediatr 2002;140:171-6)

Risk Factors for Chronic Lung Disease in the Surfactant Era: A North Carolina Population-based Study of Very Low Birth Weight Infants

To identify risk factors for chronic lung disease (CLD) in a population-based cohort of very low birth weight infants, born in an era of surfactant usage. We specifically investigated the effects of antenatal steroids, nosocomial infection, patent ductus arteriosus (PDA), fluid management, and ventilator support strategies. Data were prospectively collected on 1244 infants born in North Carolina in 1994 with birth weights 500 to 1500 g, and treated at 1 of the 13 intensive care nurseries across the state. The outcome of interest was CLD, defined as dependency on supplemental oxygen at 36 weeks' postmenstrual age. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression models. Among 865 survivors to 36 weeks' postmenstrual age, 224 (26%) had CLD. Nosocomial infection (OR: 2.0; 95% CI: 1.4-3.3), fluid intake on day 2 (OR: 1.06 per 10 mL increase; 95% CI: 1.01-1.11), and the need for ventilation at 48 hours of life (OR: 2.2; 95% CI: 1.3-3.7) were associated with an increased risk of CLD. Among infants ventilated at 48 hours, nosocomial infection (OR: 1.64; 95% CI: 1.02-2.62) and PDA (OR: 1.9; 95% CI: 1.2-3.1) were associated with an increased risk. No association was found with antenatal steroid receipt or increased levels of ventilator support. This analysis suggests that with widespread use of surfactant, nosocomial infection, PDA, and water balance persist as risk factors for CLD.