Pulmonary Outcomes in Children Born Extremely and Very Preterm at 11 Years of Age

Abstract

Background: There is increasing evidence of prematurity being a risk factor for long-term respiratory outcomes regardless the presence of bronchopulmonary dysplasia (BPD).Aim: To assess the effect of prematurity on respiratory outcomes in children born ≤32 weeks of gestational age at 11 years of age.Materials and Methods: Fifty five ex-preterm children (≤ 32 weeks of gestational age), born in Chieti between January 1, 2006 and December 31, 2007, performed lung function and diffusing capacity test (DLCO) at 11 years of age. Furthermore, allergy evaluation by skin prick test (SPT), eosinophil blood count and assessment of eosinophilic airways inflammation by exhaled nitric oxide (FeNO) were performed. The ex-preterm group was compared to an age- and sex-matched group of term children.Results: No difference for atopic and respiratory medical history was found between ex-preterm children and term controls, except for preschool wheezing that resulted more frequent in ex-preterm children. No difference neither in school-aged asthma frequency nor in lung function assessment at 11 years of age was found between the two groups. Lower DLCO values in ex-preterm children compared to term controls regardless the presence of BPD were found; furthermore, we showed a positive association between DLCO and gestational age. Eosinophil blood count, positive SPTs and FeNO values were similar between the two groups.Conclusions: Diffusing lung capacity was decreased in ex-preterm children at 11 years of age in the absence of lung function impairment and eosinophil airway inflammation, suggesting a non-eosinophilic pattern underlying pulmonary alterations. It could be desirable to include the diffusing capacity assessment in follow-up evaluation of all ex-preterm children.

The Role of Breastfeeding on Respiratory Outcomes Later in Childhood

“…After finding that in confounder model breastfeeding duration was associated with FEV 1 z-score, FEV 1 /FVC z-score and FEF 75 % z-score, but not with DLCO z-score, we specifically investigated if the association between gestational age at birth and DLCO z-score, already described previously ( 13 ), could be explained by the mediating role of breastfeeding. We illustrated the mediation analysis in the Figure 2 .…”

“…In Italy, the Italian Health Institute report 11/44, including 3,235 preterm newborns from 56 Neonatal Intensive Care Units, confirmed that exclusively breastfeeding depended on the gestational age ( 12 ). In addition, in our previous study ( 13 ) we showed lower lung diffusing capacity (DLCO) z-score levels in ex-preterm children compared to children born at term later in childhood. Therefore, the relationship between breastfeeding and respiratory outcomes is more difficult to investigate in preterm infants than healthy controls.…”

“…The original study was not designed specifically for analyzing the association between breastfeeding and respiratory outcomes. All characteristics of the study population were described previously in our study ( 13 ). In Table 1 we summarized those mother and child characteristics which were interesting for this study aim.…”

“…We examined if the association between gestational age at birth and DLCO, already shown in our previous study ( 13 ), was explained by breastfeeding duration; we performed mediation analysis using PROCESS macro v4.0 for SPSS ( 32 ).…”

“…The primary aim of this study was to evaluate the effect of breastfeeding duration on respiratory outcomes later in childhood. As secondary outcome we also examined the mediating role of breastfeeding duration in the association between gestational age at birth and lung function, specifically diffusing capacity of the lungs which was lower in ex-preterm children compared to controls, as described in our previous study ( 13 ).…”