Exposure to Oxygen and Head Growth in Infants with Bronchopulmonary Dysplasia

Abstract

Infants with bronchopulmonary dysplasia (BPD) are known to have developmental delays, but a direct link between oxygen (O (2)) exposure and brain growth has not been explored. Our objective was to test the hypothesis that the use of O (2) is associated with delays in head growth (DHG) in premature infants with BPD. We conducted a retrospective study on a cohort of infants with BPD (birthweight [BW] < 1500 g, gestational age < 34 weeks). The study population was divided into two groups based on their head circumference (HC) measured at birth. Group 1 represented infants with birth HC > or = 50% for their age on growth chart, and Group 2 represented infants with birth HC < 50% for their age. We recorded HC at hospital discharge and at 6 months of age; and the amount of DHG was calculated (DHG = current age in weeks - the age that matches the 50th percentile for current HC). Regression analysis was conducted to determine the relationship between the duration of O (2) use and DHG in both groups, controlling for BW, discharge weight, gender, and duration of mechanical ventilation (MV). Data were expressed in mean +/- standard error of mean. A total of 137 sequential infants with BPD were studied; of them 65 infants were included in group 1 and 72 infants were included in group 2. The 2 groups did not differ in GA, gender total O (2) days, and total days on MV. At hospital discharge there was no difference between groups in terms of DHG (78% versus 83%, respectively). At 6 months of age, there were more infants in group 2 who had DHG (44% versus 67%, respectively; P < 0.01). In group 1, the amount of DHG correlated only with BW ( P = 0.05). It did not correlate with discharge weight, gender, duration of O (2) use, or duration of MV. In group 2, the amount of DHG correlated only with the duration of O (2) use ( P = 0.04) It did not correlate with BW, discharge weight, gender, or duration of MV. Each 10 days of O (2) use in group 2 was associated with 1.5 +/- 0.1 days of DHG. We concluded that duration of O (2) use is associated with a delay in head growth in infants born with HC < 50th percentile. This study does not clarify whether the use of O (2) is a marker of severity of illness or a contributing factor to DHG in infants with BPD. The mechanisms for this relation require further exploration.

Need for Supplemental Oxygen at Discharge in Infants with Bronchopulmonary Dysplasia Is Not Associated with Worse Neurodevelopmental Outcomes at 3 Years Corrected Age

“…While attempts have been made to limit the dose and duration of exposure of supplemental oxygen to the immature lungs [29]–[32], given the decreased capacity of the preterm infants to combat oxidative stress, it is not surprising that supplemental oxygen that is required for prolonged periods in this population results in significant medical consequences. The duration of exposure to supplemental oxygen has been associated with delayed head growth [33], and need for supplemental oxygen at 36 weeks PMA has been associated with significant neurodevelopmental delays at 12–24 months CA [34]–[37]. In contrast, a recent study has noted that BPD accompanied by invasive mechanical ventilation at 36 weeks PMA strongly predicted the more common bilateral CP phenotypes (assessed at 2 years), but BPD without invasive mechanical ventilation (i.e.…”

Higher fluid and lower caloric intakes: associated risk of severe bronchopulmonary dysplasia in ELBW infants

“…Head circumference is often utilized as an indirect measure of postnatal brain growth, and the literature has shown an association between suboptimal brain growth and subsequent neurodevelopmental impairment (22)(23)(24). Nesterenko, et al demonstrated a correlation between oxygen exposure and delays in head growth at six months corrected age in infants with moderate to severe BPD with birth head circumference less than the 50th percentile (25). However, it remains to be determined whether the oxygen exposure is directly related to the pathogenesis of delayed head growth or is simply a marker of clinical illness severity.…”