The burden of childhood asthma and late preterm and early term births

Respiratory, cardio-metabolic and neurodevelopmental long-term outcomes of moderate to late preterm birth: not just a near term-population. A follow-up study

Introduction

Moderate-to-late preterm infants constitute the majority within the preterm infant population. Most research on preterm infants has focused on very preterm children, often treating moderate-to-late preterm infants as similar to full-term infants. Our objective was to compare clinical, respiratory, cardio-metabolic and neurodevelopmental outcomes in adolescents aged 12-15 years born moderate and late preterm with a control group of the same age born full-term.

Methods

Observational cross-sectional study, comparing moderate-to-late preterm (32-36+6 weeks' gestational age) with full-term adolescents (37-41+6 weeks' gestational age; 75 each group). Perinatal and neonatal history were collected as well as data on respiratory evolution (ISAAC questionnaire for asthma symptoms for adolescents 13-14 years), anthropometric values, learning difficulties, behavioral test (screening questionnaire for high-performance autism spectrum disorder and evaluation test for attention deficit hyperactivity disorder), skin prick test, pulmonary function test, echocardiogram and blood pressure. A blood test with metabolic profile was conducted.

Results

Moderate-to-late preterm adolescents had more current asthma [p = 0.008, OR3 (95% CI 1.26-7.14)] and longer duration of combined treatments to control asthma (inhaled corticosteroids and anti-leukotrienes; p = 0.048). Forced vital capacity <80% was detected more often in moderate-to-late preterm patients (p = 0.013). When assessing right ventricle, moderate-to-late preterm adolescents showed better tricuspid annular plane systolic excursion z-score (p = 0.003), shortening fraction (p < 0.001) and E/A ratio z-score (p = 0.002). Regarding left ventricular assessment, moderate-to-late preterm group had smaller ventricle diastolic diameter (p = 0.04) and lower posterior wall z-score values (p = 0.037). They also showed a better S'wave z-score (p = 0.027), E wave (p = 0.005), E/A ratio (p = 0.003) and a higher septal myocardial performance index z-score (p = 0.025). Moderate-to-late preterm adolescents presented lower weight z-score (p = 0.039), body mass index z-score (p = 0.013), Waterlow weight index (p = 0.006) and higher undernutrition index [p = 0.04; OR 1.4 (95% CI 1-1.9)]. Although there were no differences in neurodevelopmental survey or behavioral tests.

Conclusion

Our findings underscore the importance of extended follow-up for this predominant group of premature infants to identify potential respiratory, cardiac and anthropometric issues that may emerge in the future.

Growth and respiratory status at 3 years of age after moderate preterm, late preterm and early term births: the Japan Environment and Children's Study

OBJECTIVE

To assess the association between gestational age at birth and the risk of growth failure and respiratory symptoms at 3 years of age.

DESIGN

Cohort study using the Japan Environment and Children's Study database.

PATIENTS

A total of 86 158 singleton infants born without physical abnormalities at 32-41 weeks of gestation were enrolled between January 2011 and March 2014.

MAIN OUTCOME MEASURES

Growth failure (weight <10th percentile and height <10th percentile) and respiratory symptoms (asthma and wheezing) at 3 years of age.

METHODS

Logistic regression analysis was used to evaluate the risk of growth failure and respiratory symptoms in the moderately preterm, late preterm and early term groups compared with the full-term group after adjusting for socioeconomic and perinatal factors. Multiple imputation was used to reduce the attrition bias related to missing data.

RESULTS

The respective adjusted ORs (95% CI) of growth failure and respiratory symptoms for the moderate preterm, late preterm and early term groups compared with the full-term group were as follows: weight <10th percentile, 2.29 (1.48-3.54), 1.43 (1.24-1.71) and 1.20 (1.12-1.28); height <10th percentile, 2.34 (1.59-3.45), 1.42 (1.25-1.60) and 1.15 (1.09-1.22); asthma, 1.63 (1.06-2.50), 1.21 (1.04-1.41) and 1.16 (1.09-1.23); and wheezing, 1.39 (1.02-1.90), 1.37 (1.25-1.51) and 1.11 (1.06-1.17).

CONCLUSION

Moderate preterm, late preterm and early term births were associated with a higher risk of growth failure and respiratory symptoms at 3 years of age than full-term births, with an inverse dose-response pattern.

Time-dependent gene-environment interactions are essential drivers of asthma initiation and persistence

Asthma is a clinical syndrome caused by heterogeneous underlying mechanisms with some of them having a strong genetic component. It is known that up to 82% of atopic asthma has a genetic background with the rest being influenced by environmental factors that cause epigenetic modification(s) of gene expression. The interaction between the gene(s) and the environment has long been regarded as the most likely explanation of asthma initiation and persistence. Lately, much attention has been given to the time frame the interaction occurs since the host response (immune or biological) to environmental triggers, differs at different developmental ages. The integration of the time variant into asthma pathogenesis is appearing to be equally important as the gene(s)-environment interaction. It seems that, all three factors should be present to trigger the asthma initiation and persistence cascade. Herein, we introduce the importance of the time variant in asthma pathogenesis and emphasize the long-term clinical significance of the time-dependent gene-environment interactions in childhood.

Long-term pulmonary outcomes of young adults born prematurely: a Polish prospective cohort study PREMATURITAS 20

BACKGROUND

The long-term consequences of prematurity are often not sufficiently recognized. To address this gap, a prospective cohort study, which is a continuation of the multicenter Polish study PREMATURITAS, was conducted, utilizing unique clinical data from 20 years ago.

OBJECTIVE

The main goal was to evaluate lung function, detect any structural abnormalities using lung ultrasound, and assess psychological well-being in young adults born between 24 and 34 weeks of gestational age (GA). Additionally, the study aimed to investigate potential associations between perinatal risk factors and abnormalities observed in pulmonary function tests (PFTs) during adulthood.

METHODS

The young survivors underwent a comprehensive set of PFTs, a lung ultrasound, along with the quality of life assessment. Information regarding the neonatal period and respiratory complications was obtained from the baseline data collected in the PREMATURITAS study.

RESULTS

A total of 52 young adults, with a mean age of 21.6 years, underwent PFTs. They were divided into two groups based on GA: 24-28 weeks (n = 12) and 29-34 weeks (n = 40). The subgroup born more prematurely had significantly higher lung clearance index (LCI), compared to the other subgroup (p = 0.013). LCI ≥ 6.99 was more frequently observed in the more premature group (50% vs. 12.5%, p = 0.005), those who did not receive prenatal steroids (p = 0.020), with a diagnosis of Respiratory Distress Syndrome (p = 0.034), those who received surfactant (p = 0.026), and mechanically ventilated ≥ 7 days (p = 0.005). Additionally, elevated LCI was associated with the diagnosis of asthma (p = 0.010).

CONCLUSIONS

The findings suggest pulmonary effects due to prematurity persist into adulthood and their insult on small airway function. Regular follow-up evaluations of young survivors born preterm should include assessments of PFTs. Specifically, the use of LCI can provide valuable insights into long-term pulmonary impairment.

Long-term outcomes of infants with severe BPD

Preterm birth disrupts the normal sequence of lung development. Additionally, interventions that support gas exchange, including positive pressure ventilation and supplemental oxygen can further exacerbate lung injury, increasing the risk of developing bronchopulmonary dysplasia (BPD) in infants born preterm. Approximately 50,000 preterm infants each year in the United States develop BPD. Heterogeneous lung pathology involving the upper and lower respiratory tract can contribute to the BPD phenotype and can be age-dependent. These phenotypes include alveolar, upper airway, large airways, small airways, and vascular. Each of these phenotypes may improve, resolve, or persist at different ages, throughout childhood. The development of BPD endotypes can be influenced by gestational age and length and type of respiratory support. Although, long-term pulmonary outcomes of infants with severe BPD are variable, the presence of small airway disease is a common phenotype in school age and adolescent children. In this review we examine the more common respiratory endotypes found in infants and children with severe BPD and discuss the long-term prognosis for cardiovascular, neurological, and gastrointestinal morbidities in this patient population.

Are Babies Born Preterm High-Risk Asthma Candidates?

Among preterm infants, the risk of developing asthma is a matter of debate. This review discusses the state of the art of poorly understood prematurity-associated asthma. Impaired pulmonary function is common in children born prematurely. Preterm infants are prone to developing viral respiratory tract infections, bronchiolitis in the first year of life, and recurrent viral wheezing in preschool age. All of these conditions may precede asthma development. We also discuss the role of both atopic sensitization and intestinal microbiome and, consequently, immune maturation. Diet and pollution have been considered to better understand how prematurity could be associated with asthma. Understanding the effect of factors involved in asthma onset may pave the way to improve the prediction of this asthma phenotype.

Preterm Birth, Developmental Smoke/Nicotine Exposure, and Life-Long Pulmonary Sequelae

This review delineates the main pulmonary issues related to preterm birth, perinatal tobacco/nicotine exposure, and its effects on offspring, focusing on respiratory health and its possible transmission to subsequent generations. We review the extent of the problem of preterm birth, prematurity-related pulmonary effects, and the associated increased risk of asthma later in life. We then review the impact of developmental tobacco/nicotine exposure on offspring asthma and the significance of transgenerational pulmonary effects following perinatal tobacco/nicotine exposure, possibly via its effects on germline epigenetics.

Time-Specific Factors Influencing the Development of Asthma in Children

Susceptibility to asthma is complex and heterogeneous, as it involves both genetic and environmental insults (pre- and post-birth) acting in a critical window of development in early life. According to the Developmental Origins of Health and Disease, several factors, both harmful and protective, such as nutrition, diseases, drugs, microbiome, and stressors, interact with genotypic variation to change the capacity of the organism to successfully adapt and grow in later life. In this review, we aim to provide the latest evidence about predictive risk and protective factors for developing asthma in different stages of life, from the fetal period to adolescence, in order to develop strategic preventive and therapeutic interventions to predict and improve health later in life. Our study shows that for some risk factors, such as exposure to cigarette smoke, environmental pollutants, and family history of asthma, the evidence in favor of a strong association of those factors with the development of asthma is solid and widely shared. Similarly, the clear benefits of some protective factors were shown, providing new insights into primary prevention. On the contrary, further longitudinal studies are required, as some points in the literature remain controversial and a source of debate.

nnLong-Term Respiratory Outcomes in Early Term Born Offspring: A Systematic Review and Meta-Analysis

OBJECTIVE

Newborns exhibit the lowest immediate respiratory morbidity rates when born at full term (39-40) completed weeks of gestation. We evaluated whether early-term deliveries (37^0/7-38^6/7 weeks of gestation) bare a significant impact on overall and specific long-term respiratory outcomes of offspring up to the age of 18 years, as compared to offspring born at full term or later.

DATA SOURCES

PubMed/Medline, EMBASE, and relevant reference lists from January 2012 to May 2020.

STUDY ELIGIBILITY CRITERIA

This systematic review and meta-analysis was conducted according to the PRISMA guidelines and was registered in PROSPERO. Any observational or randomized human trials addressing the association between early term delivery and long-term respiratory outcomes in the offspring, restricted to studies published in English, were included. Search included terms relating to gestational age, pediatric morbidity, and respiratory outcomes. We included studies assessing long term respiratory disease (1-18 years) of offspring born during early term as compared to full term and later.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two independent reviewers extracted data and assessed risk of bias. Using a random-effect meta-analysis, pooled relative risk with their 95% confidence intervals and heterogeneity were determined. Publication bias was assessed by Funnel plots with Eggers regression line and contours, and sensitivity analyses were performed using Baujat plots.

RESULTS

Fourteen studies were included following a screen of nearly 2500 abstracts. These studies included nearly eight million patients, and were subjected to qualitative and quantitative analyses. Early term delivery significantly increased the risk of total respiratory morbidity in the offspring (RR= 1.20, 95% CI= 1.16, 1.26) as compared to full term delivery. The increased respiratory morbidity was attributed to obstructive airway diseases (RR=1.19, 95% CI= 1.12, 1.27) and infectious respiratory diseases (RR= 1.22, 95% CI= 1.17, 1.29). Most studies were of acceptable quality.

CONCLUSION

This comprehensive meta-analysis suggests that early term delivery poses a risk for long term pediatric respiratory morbidity, as compared to full term delivery. Notably, other factors over the years cannot be accounted for. This adds an important perspective to be considered when balancing the fetal, maternal, and neonatal risks associated with delivery timing.

Low length/weight growth trajectories of early-term infants during the first year: evidence from a longitudinal study in China

OBJECTIVE

To identify common length, weight and body mass index (BMI) growth trajectories of term infants during infancy, and to determine their association with early-term infants.

DESIGN

Prospective longitudinal study.

SETTING

Wuhan, China.

PATIENTS

A total of 4308 term infants (born at 37-41 weeks of gestation) were included. All term infants were single live birth with no defects and birth weight ≥2500 g, and their mothers were permanent residents of Wuhan for more than 2 years. After excluding 887 infants, a total of 3421 term infants (1028 early-term infants born at 37-38 weeks of gestation and 2393 full-term infants born at 39-41 weeks of gestation) entered the statistical analysis stage.

MAIN OUTCOME MEASURES

Patterns of length, weight and BMI growth trajectories by using group-based trajectory modelling.

RESULTS

Three distinct physical growth trajectories were identified as follows: length: low stable (1056, 30.9%), moderate stable (1887, 55.2%) and high increasing (477, 13.9%); weight: low stable (1031, 30.1%), moderate stable (1884, 55.1%) and high increasing (505, 14.8%); BMI: low stable (689, 20.1%), moderate stable (2167, 63.4%) and high increasing (564, 16.5%). Compared with the full-term infants, early-term infants were more likely to remain at low-stable trajectory in length (OR: 1.40; 95% CI: 1.19 to 1.66) and weight (OR:1.29; 95% CI: 1.09 to 1.53). These associations were still statistically significant after adjusting potential confounders and were more evident among girls in the stratified analysis. There was no statistical association between BMI trajectory patterns and gestational age categories.

CONCLUSION

Our results suggested the heterogeneity of term infants existed in length, weight and BMI growth trajectories of early childhood. Compared with full-term birth, early-term birth was related to low length and weight trajectories rather than BMI trajectory. Further research is needed to evaluate the duration of these low trajectories and their possible long-term health effects.

Impact of early life exposures on respiratory disease

The antecedents of asthma and chronic obstructive pulmonary disease (COPD) lie before school age. Adverse effects are transgenerational, antenatal and in the preschool years. Antenatal adverse effects impair spirometry by causing low birth weight, altered lung structure and immune function, and sensitizing the foetus to later insults. The key stages of normal lung health are lung function at birth, lung growth to a plateau age 20-25 years, and the phase of decline thereafter; contrary to perceived wisdom, accelerated decline is not related to smoking. There are different trajectories of lung function. Lung function usually tracks from preschool to late middle age. Asthma is driven by antenatal and early life influences. The airflow obstruction, emphysema and multi-morbidity of COPD all start early. Failure to reach a normal plateau and accelerated decline in lung function are risk factors for COPD. Airway disease cannot be prevented in adult life; prevention must start early.

The role of parental education on the relationship between gestational age and school outcomes

BACKGROUND

Individuals born preterm may experience difficulties beyond the neonatal period, such as poorer school outcomes. However, whether these outcomes are modified by family factors is less well-known.

OBJECTIVES

To investigate whether parental educational level modify the relationship of gestational age with completion of final examinations and grade point average in compulsory education.

METHODS

This nationwide register-based cohort study included singletons born in Denmark during 1995-2001. We investigated the differences in the associations between gestational age (24-44 weeks) and two school outcomes at 16 years according to parental educational level (lower (≤10 years), intermediate (11-13 years), and higher (>13 years)). Mixed-effect logistic regression and mixed-effect linear regression were used to model completion of final examination and grade point average, respectively.

RESULTS

Of the 425 101 singletons, 4.7% were born before 37 weeks. The risk of not completing final examination increased with shorter gestational age and lower parental educational level. For instance, among adolescents whose parents had a lower educational level, the risk increased from 23.9% (95% CI, 23.1, 24.6) for those born in week 40 to 36.6% (95% CI, 31.5, 42.1) for those born in week 28. For adolescents whose parents had a higher educational level, the corresponding risk increase was 5.9% (95% CI, 5.7, 6.1) to 10.5% (95% CI, 8.6, 12.8), respectively. Grade point average decreased with shorter gestational age in adolescents born before 30 weeks and with lower parental educational level. The associations between gestational age and grade point average were similar across parental educational levels. For completions of final examination, the associations with gestational age were weaker with higher parental educational level.

CONCLUSIONS

Shorter gestational age and lower parental educational level were associated with poorer school outcomes. Our findings suggest that parental educational level mitigates the adverse effects of shorter gestational age on some school outcomes.

Challenging the paradigm: moving from umbrella labels to treatable traits in airway disease

Airway diseases were initially described by nonspecific patterns of symptoms, for example "dry and wheezy" and "wet and crackly". The model airway disease is cystic fibrosis, which has progressed from nonspecific reactive treatments such as antibiotics for airway infection to molecular sub-endotype, proactive therapies with an unequivocal evidence base, early diagnosis, and biomarkers of treatment efficacy. Unfortunately, other airway diseases lag behind, not least because nonspecific umbrella labels such as "asthma" are considered to be diagnoses not mere descriptions. Pending the delineation of molecular sub-endotypes in other airway disease the concept of treatable traits, and consideration of airway disease in a wider context is preferable. A treatable trait is a characteristic amenable to therapy, with measurable benefits of treatment. This approach determines what pathology is actually present and treatable, rather than using umbrella labels. We determine if airway inflammation is present, and whether there is airway eosinophilia which will likely respond to inhaled corticosteroids; whether there is variable airflow obstruction due to bronchoconstriction which will respond to β2-agonists; and whether there is unsuspected underlying airway infection which should be treated with antibiotics unless there is an underlying endotype which can be addressed, as for example an immunodeficiency. The context of airway disease should also be extrapulmonary comorbidities, social and environmental factors, and a developmental perspective, particularly this last aspect if preventive strategies are being contemplated. This approach allows targeted treatment for maximal patient benefit, as well as preventing the discarding of therapies which are useful for appropriate subgroups of patients. Failure to appreciate this almost led to the discarding of valuable treatments such as prednisolone.

EDUCATIONAL AIMS

To use cystic fibrosis as a paradigm to show the benefits of the journey from nonspecific umbrella terms to specific endotypes and sub-endotypes, as a road map for other airway diseases to follow.Demonstrate that nonspecific labels to describe airway disease can and should be abandoned in favour of treatable traits to ensure diagnostic and therapeutic precision.Begin to learn to see airway disease in the context of extrapulmonary comorbidities, and social and environmental factors, as well as with a developmental perspective.

CPAP protects against hyperoxia-induced increase in airway reactivity in neonatal mice

BACKGROUND

Oxygen and continuous positive airway pressure (CPAP) are primary modes of respiratory support for preterm infants. Animal models, however, have demonstrated adverse unintended effects of hyperoxia and CPAP on lung development. We investigate the effects of combined neonatal hyperoxia and CPAP exposure on airway function and morphology in mice.

METHODS

Newborn mice were exposed to hyperoxia (40% O₂) 24 h/day for 7 consecutive days with or without daily (3 h/day) concomitant CPAP. Two weeks after CPAP and/or hyperoxia treatment ended, lungs were assessed for airway (AW) hyperreactivity and morphology.

RESULTS

CPAP and hyperoxia exposure alone increased airway reactivity compared to untreated control mice. CPAP-induced airway hyperreactivity was associated with epithelial and smooth muscle proliferation. In contrast, combined CPAP and hyperoxia treatment no longer resulted in increased airway reactivity, which was associated with normalization of smooth muscle and epithelial proliferation to values similar to untreated mice.

CONCLUSIONS

Our data suggest that the combination of CPAP and hyperoxia decreases the adverse consequences on airway remodeling of either intervention alone. The complex interaction between mechanical stretch (via CPAP) and hyperoxia exposure on development of immature airways has implications for the pathophysiology of airway disease in former preterm infants receiving non-invasive respiratory support.

IMPACT

CPAP and mild hyperoxia exposure alone increase airway reactivity in the neonatal mouse model. In contrast, combined CPAP and hyperoxia no longer induce airway hyperreactivity. Combined CPAP and hyperoxia normalize smooth muscle and epithelial proliferation to control values. Interaction between CPAP-induced stretch and mild hyperoxia exposure on immature airways has important implications for airway pathophysiology in former preterm infants.

Maternal Depressive Symptoms, Sleep, and Odds of Spontaneous Early Birth: Implications for Racial Inequities in Birth Outcomes

STUDY OBJECTIVES

Delivery prior to full term affects 37% of US births, including ~400,000 preterm births (<37 weeks) and >1,000,000 early term births (37-38 weeks). Approximately 70% of cases of shortened gestation are spontaneous - without medically-indicated cause. Elucidation of modifiable behavioral factors would have considerable clinical impact.

METHODS

This study examined the role of depressive symptoms and sleep quality in predicting the odds of spontaneous shortened gestation among 317 women (135 Black, 182 White) who completed psychosocial assessment in mid-pregnancy.

RESULTS

Adjusting for key covariates, Black women had 1.89 times higher odds of spontaneous shortened gestation compared to White women (OR (95% CI) = 1.89 (1.01, 3.53), p=0.046). Women who reported only poor subjective sleep quality (PSQI > 6) or only elevated depressive symptoms (CES-D ≥ 16) exhibited no statistically significant differences in odds of spontaneous shortened gestation compared to those with neither risk factor. However, women with comorbid poor sleep and depressive symptoms exhibited markedly higher odds of spontaneous shortened gestation than those with neither risk factor [39.2% versus 15.7%, [OR (95% CI) = 2.69 (1.27, 5.70), p = 0.01]. A higher proportion of Black women met criteria for both risk factors (23% of Black women versus 11% of White women; p=0.004), with a lower proportion experiencing neither risk factor (40.7% of Black versus 64.3% of White women; p < 0.001).

CONCLUSIONS

Additive effects of poor subjective sleep quality and depressive symptoms were observed with markedly higher odds of spontaneous shortened gestation among women with both risk factors. Racial inequities in rates of comorbid exposure corresponded with inequities in shortened gestation. Future empirical studies and intervention efforts should consider the interactive effects of these commonly co-morbid exposures.

Short-Term and Long-Term Educational Outcomes of Infants Born Moderately and Late Preterm

OBJECTIVE

To assess the relationship of moderate and late preterm birth (32^0/7-36^6/7 weeks) to long-term educational outcomes.

STUDY DESIGN

We hypothesized that moderate and late preterm birth would be associated with adverse outcomes in elementary school. To test this, we linked vital statistics patient discharge data from the Office of Statewide Health Planning and Development including birth outcomes, to the 2015-2016 school year administrative data of a large, urban school district (n = 72 316). We compared the relative risk of moderate and late preterm and term infants for later adverse neurocognitive and behavioral outcomes in kindergarten through the 12th grade.

RESULTS

After adjusting for socioeconomic status, compared with term birth, moderate and late preterm birth was associated with an increased risk of low performance in mathematics and English language arts, chronic absenteeism, and suspension. These risks emerged in kindergarten through grade 2 and remained in grades 3-5, but seemed to wash out in later grades, with the exception of suspension, which remained through grades 9-12.

CONCLUSIONS

Confirming our hypothesis, moderate and late preterm birth was associated with adverse educational outcomes in late elementary school, indicating that it is a significant risk factor that school districts could leverage when targeting early intervention. Future studies will need to test these relations in geographically and socioeconomically diverse school districts, include a wider variety of outcomes, and consider how early interventions moderate associations between birth outcomes and educational outcomes.

Intravenous paracetamol for neonates: long-term diseases not escalated during 5 years of follow-up

OBJECTIVE

To evaluate the long-term adverse reactions of paracetamol in children who required intensive care shortly after birth. Paracetamol is a widely used analgesic in neonates, but the long-term studies are lacking. Previous epidemiological studies have reported associations between early paracetamol intake and diseases in childhood.

DESIGN

Five-year follow-up cohort of children who required intensive care shortly after birth.

SETTING

Single tertiary care hospital; neonatal and paediatric intensive care units.

INTERVENTIONS

Intravenous paracetamol was administered for pain and discomfort to the neonates during their intensive care, while for the control infants, it was not available.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of asthma; secondary outcomes were neonatal diseases and long-term morbidities (atopic dermatitis, inflammatory bowel disease, autism, speech disorders, cerebral palsy). Long-term morbidities were adjusted based on antenatal and neonatal risk factors.

RESULTS

We screened all neonates admitted to the intensive care units soon after birth in Oulu University Hospital, Oulu, Finland, during 1 October 2007 to 31 December 2013. Altogether, 1552 infants needed intensive care. Of them, 735 (47%) were treated with intravenous paracetamol. We obtained their long-term data from the Finnish National Institute for Health and Welfare, including all physician-made diagnoses from all primary healthcare units and hospitals in Finland. We found no difference in the asthma incidence or in other long-term morbidities between paracetamol-treated and non-exposed infants.

CONCLUSIONS

Intravenous paracetamol given to neonates did not associate with childhood disorders compared with the non-exposed infants during the 5-year follow-up. The previous hypothesis that early paracetamol use causes childhood morbidities was not confirmed.

Impact of moderate and late preterm birth on neurodevelopment, brain development and respiratory health at school age: protocol for a longitudinal cohort study (LaPrem study)

INTRODUCTION

Children born moderate to late preterm (MLP, 32-36 weeks' gestation) account for approximately 85% of all preterm births globally. Compared with children born at term, children born MLP are at increased risk of poor neurodevelopmental outcomes. Despite making up the largest group of preterm children, developmental outcomes of children born MLP are less well studied than in other preterm groups. This study aimed to (1) compare neurodevelopmental, respiratory health and brain magnetic resonance imaging (MRI) outcomes between children born MLP and term at 9 years of age; (2) examine the differences in brain growth trajectory from infancy to 9 years between children born MLP and term; and in children born MLP; (3) examine the relationship between brain development and neurodevelopment at 9 years; and (4) identify risk factors for poorer outcomes at 9 years.

METHODS AND ANALYSIS

The "LaPrem" (Late Preterm MRI Study) study is a longitudinal cohort study of children born MLP and term controls, born at the Royal Women's Hospital in Melbourne, Australia, between 2010 and 2013. Participants were recruited in the neonatal period and were previously followed up at 2 and 5 years. This 9-year school-age follow-up includes neuropsychology, motor and physical activities, and lung function assessments, as well as brain MRI. Outcomes at 9 years will be compared between birth groups using linear and logistic regressions. Trajectories of brain development will be compared between birth groups using mixed effects models. The relationships between MRI and neurodevelopmental outcomes, as well as other early predictors of poor 9-year outcomes, will be explored using linear and logistic regression.

ETHICS AND DISSEMINATION

This study was approved by the human research ethics committee at the Royal Children's Hospital, Melbourne, Australia. Study outcomes will be disseminated through peer-reviewed publications, conference presentations and social media.

Predicting Long-Term Respiratory Outcomes in Premature Infants: Is It Time to Move beyond Bronchopulmonary Dysplasia?

Premature birth has been shown to be associated with adverse respiratory health in children and adults; children diagnosed with bronchopulmonary dysplasia (BPD) in infancy are at particularly high risk. Since its first description by Northway et al. about half a century ago, the definition of BPD has gone through several iterations reflecting the changes in the patient population, advancements in knowledge of lung development and injury, and improvements in perinatal care practices. One of the key benchmarks for optimally defining BPD has been the ability to predict long-term respiratory and health outcomes. This definition is needed by multiple stakeholders for hosts of reasons including: providing parents with some expectations for the future, to guide clinicians for developing longer term follow-up practices, to assist policy makers to allocate resources, and to support researchers involved in developing preventive or therapeutic strategies and designing studies with meaningful outcome measures. Long-term respiratory outcomes in preterm infants with BPD have shown variable results reflecting not only limitations of the current definition of BPD, but also potentially the impact of other prenatal, postnatal and childhood factors on the respiratory health. In this manuscript, we present an overview of the long-term respiratory outcomes in infants with BPD and discuss the role of other modifiable or non-modifiable factors affecting respiratory health in preterm infants. We will also discuss the limitations of using BPD as a predictor of respiratory morbidities and some of the recent advances in delineating the causes and severity of respiratory insufficiency in infants diagnosed with BPD.

Impact of Prematurity and Severe Viral Bronchiolitis on Asthma Development at 6-9 Years

Background

Premature birth is associated with increased susceptibility for viral infections and chronic airway morbidity. Preterm children, even moderate and late, may be at risk for short- and long-term respiratory morbidities.

Objective

Our main goal was to compare the burden of two conditions, severe bronchiolitis and prematurity (early and moderate-late), on asthma development at 6–9 years.

Patients and Methods

A retrospective cohort of all preterm (<37weeks gestational age) and full-term children hospitalized for bronchiolitis, with current age between 6 and 9 years, was created. A second cohort was made up of preterm children, without admission for bronchiolitis, randomly chosen from the hospital premature births database. Prevalence and risk factors for asthma were analysed. Parents completed the International Study of Asthma and Allergies in Childhood (ISAAC) Questionnaire for asthma symptoms for children 6–7 years. Lung function and aeroallergen sensitization were evaluated.

Results

Of the 480 selected children, 399 could be contacted and agreed to participate: 133 preterm and 114 full-term cases with admission for bronchiolitis and 146 preterm control children without admission for bronchiolitis. The frequency of current asthma at 6–9 years was higher in preterm cases (27%) compared with full-term-cases (15%) and preterm controls (14%) (p=0.04). Among hospitalized-bronchiolitis children, prematurity (p=0.04), rhinovirus infection (p=0.03), viral coinfection (p=0.04) and paternal asthma (p=0.003) were risk factors for asthma at 6–9 years. Among premature children, with and without bronchiolitis admission, the risk factors for asthma at 6–9 years were admission for bronchiolitis (p=0.03) and aeroallergen sensitisation (p=0.01). Moderate and late preterm children without admission for bronchiolitis showed similar prevalence of current asthma than full-term ones, previously admitted for bronchiolitis.

Conclusion

Preterm birth is an important early life risk factor for asthma in childhood. The addition of other risk factors, such as severe bronchiolitis, especially by rhinovirus or viral coinfections, are associated with even higher risk for subsequent asthma.

Preterm birth and sustained inflammation: consequences for the neonate

Almost half of all preterm births are caused or triggered by an inflammatory process at the feto-maternal interface resulting in preterm labor or rupture of membranes with or without chorioamnionitis (“first inflammatory hit”). Preterm babies have highly vulnerable body surfaces and immature organ systems. They are postnatally confronted with a drastically altered antigen exposure including hospital-specific microbes, artificial devices, drugs, nutritional antigens, and hypoxia or hyperoxia (“second inflammatory hit”). This is of particular importance to extremely preterm infants born before 28 weeks, as they have not experienced important “third-trimester” adaptation processes to tolerate maternal and self-antigens. Instead of a balanced adaptation to extrauterine life, the delicate co-regulation between immune defense mechanisms and immunosuppression (tolerance) to allow microbiome establishment is therefore often disturbed. Hence, preterm infants are predisposed to sepsis but also to several injurious conditions that can contribute to the onset or perpetuation of sustained inflammation (SI). This is a continuing challenge to clinicians involved in the care of preterm infants, as SI is regarded as a crucial mediator for mortality and the development of morbidities in preterm infants. This review will outline the (i) role of inflammation for short-term consequences of preterm birth and (ii) the effect of SI on organ development and long-term outcome.

S100-Alarmins Are Essential Pilots of Postnatal Innate Immune Adaptation

The restricted capacity of newborn infants to mount inflammatory responses toward microbial challenges has traditionally been linked to the high risk of septic diseases during the neonatal period. In recent years, substantial evidence has been provided that this characteristic of the neonatal immune system is actually a meaningful physiologic state that is based on specific transiently active cellular and molecular mechanisms and required for a favorable course of postnatal immune adaptation. The identification of physiologically high amounts of S100-alarmins in neonates has been one of the crucial pieces in the puzzle that contributed to the change of concept. In this context, innate immune immaturity could be redefined and assigned to the epigenetic silence of adult-like cell-autonomous regulation at the beginning of life. S100-alarmins represent an alternative age-specific mechanism of immune regulation that protects neonates from hyperinflammatory immune responses. Here, we summarize how infants are provided with S100-alarmins and why these allow an uneventful clash between the innate immune system and the extrauterine world. The mode of action of S100-alarmins is highlighted including their tuning functions at multiple levels for establishing a state of homeostasis with the environment in the newborn individual.

Hospital admissions for lower respiratory tract infections after early-, late-, and post-term birth

BACKGROUND

Recent data suggest that early-term births are associated with later respiratory morbidity (LRTI), and post-term births may decrease this risk.

OBJECTIVES

The objective was to determine the impact of early-term, late-term, and post-term birth on hospital admission for LRTI up to the age of seven years. Additionally, we explored maternal and perinatal factors associated with the risk of admission for LRTIs.

METHODS

The association of early-term (37⁺⁰ -38⁺⁶  weeks), late-term (41⁺⁰ -41⁺⁶  weeks), and post-term (≥42 weeks) birth with hospital admissions for lower respiratory tract infections (LRTI) in comparison with infants born full-term (39⁺⁰ -40⁺⁶  weeks) was assessed and early predictors of LRTI were established. The register study included 948 695 infants born in Finland in 1991-2008. Data were analysed in four-term subgroups. Hospital admissions for bronchiolitis/bronchitis and pneumonia were collected up to 7 years of age. Adjusted Cox proportional hazards models were used to assess risk factors of LRTI admissions.

RESULTS

The rates of hospital admission in the early-, full-, late-, and post-term groups were 6.7%, 5.5%, 5.1%, and 4.8% for bronchiolitis/bronchitis, and 2.8%, 2.4%, 2.3%, and 2.3% for pneumonia. Early-term birth was associated with an increased risk of admission for bronchiolitis/bronchitis (hazard ratio HR 1.21, 95% confidence interval CI 1.18, 1.23) and pneumonia (HR 1.16, 95% CI 1.12, 1.20), while late-term (HR 0.93, 95% CI 0.91, 0.95) and post-term births (HR 0.89, 95% CI 0.85, 0.93) were associated with a decreased risk of bronchiolitis/bronchitis admission compared with the full-term group. Maternal age ≤ 20 years, smoking during pregnancy, male sex, caesarean delivery, small for gestational age, 1-minute Apgar score < 4, ventilator support, and neonatal antibiotic therapy were associated with an increased risk of LRTI admission, while being firstborn, born in a level-II hospital and in the Northern region was associated with decreased risk.

CONCLUSION

Early-term birth was associated with a higher risk of all LRTI admissions while late-term and post-term births were associated with lower risk of bronchiolitis/bronchitis admission. Modifiable risk factors of LRTIs were smoking during pregnancy, birth by elective caesarean delivery, neonatal ventilator support, and antibiotic therapy.

Hyperoxia-induced Cellular Senescence in Fetal Airway Smooth Muscle Cells

Supplemental O₂ (hyperoxia; 30-90% O₂) is a necessary intervention for premature infants, but it contributes to development of neonatal and pediatric asthma, necessitating better understanding of contributory mechanisms in hyperoxia-induced changes to airway structure and function. In adults, environmental stressors promote formation of senescent cells that secrete factors (senescence-associated secretory phenotype), which can be inflammatory and have paracrine effects that enhance chronic lung diseases. Hyperoxia-induced changes in airway structure and function are mediated in part by effects on airway smooth muscle (ASM). In the present study, using human fetal ASM cells as a model of prematurity, we ascertained the effects of clinically relevant moderate hyperoxia (40% O₂) on cellular senescence. Fetal ASM exposed to 40% O₂ for 7 days exhibited elevated concentrations of senescence-associated markers, including β-galactosidase; cell cycle checkpoint proteins p16, p21, and p-p53; and the DNA damage marker p-γH2A.X (phosphorylated γ-histone family member X). The combination of dasatinib and quercetin, compounds known to eliminate senescent cells (senolytics), reduced the number of hyperoxia-exposed β-galactosidase-, p21-, p16-, and p-γH2A.X-positive ASM cells. The senescence-associated secretory phenotype profile of hyperoxia-exposed cells included both profibrotic and proinflammatory mediators. Naive ASM exposed to media from hyperoxia-exposed senescent cells exhibited increased collagen and fibronectin and higher contractility. Our data show that induction of cellular senescence by hyperoxia leads to secretion of inflammatory factors and has a functional effect on naive ASM. Cellular senescence in the airway may thus contribute to pediatric airway disease in the context of sequelae of preterm birth.

Respiratory Phenotypes for Preterm Infants, Children, and Adults: Bronchopulmonary Dysplasia and More

Ongoing advancements in neonatal care since the late 1980s have led to increased numbers of premature infants surviving well beyond the neonatal period. As a result of increased survival, many individuals born preterm manifest chronic respiratory symptoms throughout infancy, childhood, and adult life. The archetypical respiratory disease of prematurity, bronchopulmonary dysplasia, is the second most common chronic pediatric respiratory disease after asthma. However, there are several commonly held misconceptions. These misconceptions include that bronchopulmonary dysplasia is rare, that bronchopulmonary dysplasia resolves within the first few years of life, and that bronchopulmonary dysplasia does not impact respiratory health in adult life. This focused review describes a spectrum of respiratory conditions that individuals born prematurely may experience throughout their lifespan. Specifically, this review provides quantitative estimates of the number of individuals with alveolar, airway, and vascular phenotypes associated with bronchopulmonary dysplasia, as well as non-bronchopulmonary dysplasia respiratory phenotypes such as airway malacia, obstructive sleep apnea, and control of breathing issues. Furthermore, this review illustrates what is known about the potential for progression and/or lack of resolution of these respiratory phenotypes in childhood and adult life. Recognizing the spectrum of respiratory phenotypes associated with individuals born preterm and providing comprehensive and personalized care to these individuals may help to modulate adverse respiratory outcomes in later life.

Effect of late preterm birth on lung clearance index and respiratory physiology in school-age children

BACKGROUND

We hypothesized that former late preterm (LP) children have abnormal pulmonary physiology parameters, including uneven ventilation distribution, due to premature disruption of normal lung development.

METHODS

A cross-sectional study evaluating former LP children at the age of 6 to 12 years as compared to term controls. Demographics and child's and family history of asthma/atopy/smoking were recorded. The outcome parameters were spirometry, multiple breath washout (MBW) measurement by lung clearance index (LCI), 6-minute walk test (6MWT), symptoms related to asthma and allergy, and Godin Leisure-Time Exercise Questionnaire.

RESULTS

Twenty-nine former LP were compared to 30 term-control children (mean age, 8.2 ± 1.7 and 8.8 ± 1.8 years, respectively). LP had reduced forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) compared to term controls (FEV1 1.59 ± 0.48 vs 1.80 ± 0.39 L, P = 0.005 and FVC 1.73 ± 0.45 vs 1.99 ± 0.49 L, P = 0.009). There were no differences between the two groups regarding FEV1/FVC, forced expiratory flow between 25 and 75 (FEF25-75), LCI (7.10 ± 0.79 vs 6.96 ± 0.75, P = 0.50), 6MW distance, and weekly leisure-activity score. Former LP children had more episodes of wheezing and greater use of asthma medication.

CONCLUSIONS

This pilot study suggests that LP have lower pulmonary function tests (PFTs) but not ventilation inhomogeneity measured by LCI or functional disturbance. It is unclear if the differences in PFTs are due to late prematurity by itself or are the consequence of maternal and neonatal factors associated with LP. Further larger studies are required to assess the long-term respiratory consequences of LP birth.

Respiratory morbidity, atopy and asthma at school age in preterm infants aged 32-35 weeks

Little is known about respiratory morbidity and asthma risk in preterm infants (PTIs) with a gestational age (GA) over 32 weeks. This was a prospective study carried out from birth to 7-8 years, comparing two groups: (a) PTIs (GAs 32 weeks + 1 day to 35 weeks + 0 days, without comorbidities) and (b) full-term infants (FTIs; GA ≥ 37 weeks). Risk and protective factors for bronchiolitis and asthma were identified. A total of 232 children (116/group) were included. Sixty-six (56.9%) PTIs and 43 (37.1%) FTIs presented bronchiolitis (p = 0.002). Recurrent wheezing was 52 (44.8%) on PTIs versus 36 (31.0%) on FTIs (p = 0.03). Asthma at school aged was 27 (23.3%) on PTIs and 8 (6.9%) on FTIs (p = 0.020). Asthma risk factors were only detected in group A.Conclusion: PTIs had a higher prevalence of bronchiolitis, recurrent wheezing and asthma; risk factors for asthma are the following: older siblings, allergic father, atopic dermatitis and antibiotic treatment in the first 3 years of life and prematurity itself, which also acted as protective factor for atopic dermatitis. What is known: • In recent decades, there has been a significant increase in the birth of premature babies and consequently, also in the pathologies secondary to the prematurity: a greater number of complications and disorders related to the development and maturation of many organs and systems, especially the respiratory system. Several studies, especially in full-term infants and very preterm infants, have tried to elucidate the risk factors that may influence the development of persistent or chronic respiratory problems such asasthma, but little is known about the aetiology of these disorders in the late or moderate preterm infants. Inthis group of children, the role played by certain factors (early use of antibiotics, chorioamnionitis, smokeexposure, paternal asthma, etc.) on late respiratory morbidity, or asthma, is inconclusive. • Moderate-to-late preterm infants are more predisposed to developing recurrent wheezing/asthma and should adopt control measures. What is new: • Our work provides data related to little-understood aspects of respiratory diseases in this group of late or moderate preterm infants (gestational age between 32 weeks plus 1 day and 35 weeks plus 0 days), by monitoring their evolution from birth to 7-8 years of age, compared with another group of full-term newborns. We aimed to establish the prevalence of bronchiolitis and recurrent wheezing in these children during their first years of life. • The prevalence of school-aged asthma and the risk factors for contracting it were also investigated.

At the forefront of psychoneuroimmunology in pregnancy: Implications for racial disparities in birth outcomes PART 1: Behavioral risks factors

Birth prior to full term is a substantial public health issue. In the US, ˜400,000 babies per year are born preterm (<37 weeks), while>1 million are early term (37-38^6/7 weeks). Birth prior to full term confers risk both immediate and long term, including neonatal intensive care, decrements in school performance, and increased mortality risk from infancy through young adulthood. Risk for low birth weight and preterm birth are 1.5-2 times greater among African Americans versus Whites. Psychosocial stress related to being a member of a discriminated racial minority group contributes substantially to these racial disparities. Providing promising targets for intervention, depressed mood, anxiety, and poor sleep are each linked with exposure to chronic stress, including racial discrimination. A rigorous transdisciplinary approach addressing these gaps holds great promise for clinical impact in addressing racial disparities as well as ameliorating effects of stress on perinatal health more broadly. As will be reviewed in a companion paper, the mechanistic roles of physiological sequelae to stress - including neuroendocrine, inflammatory regulation, biological aging, and the microbiome - also require delineation.

Timing of elective pre-labour caesarean section: A decision analysis

BACKGROUND

Since caesarean sections (CSs) before 39+0  weeks gestation are associated with higher rates of neonatal respiratory morbidity, it is recommended to delay elective CSs until 39+0  weeks. However, this bears the risk of earlier spontaneous labour resulting in unplanned CSs, which has workforce and resource implications, specifically in smaller obstetric units.

AIM

To assess, in a policy of elective CSs from 39+0  weeks onward, the number of unplanned CSs to prevent one neonate with respiratory complications, as compared to early elective CS.

MATERIALS AND METHODS

We performed a decision analysis comparing early term elective CS at 37+0-6 or 38+0-6  weeks to elective prelabour CS, without strict medical indication, at 39+0-6  weeks, with earlier unplanned CS, in women with uncomplicated singleton pregnancies. We used literature data to calculate the number of unplanned CSs necessary to prevent one neonate with respiratory morbidity.

RESULTS

Planning all elective CSs at 39+0-6  weeks required 10.9 unplanned CSs to prevent one neonate with respiratory morbidity, compared to planning all elective CSs at 38+0-6  weeks. Compared to planning all elective CSs at 37+0-6  weeks we needed to perform 3.3 unplanned CSs to prevent one neonate with respiratory morbidity.

CONCLUSION

In a policy of planning all elective pre-labour CSs from 39+0  weeks of gestation onward, between three and 11 unplanned CSs have to be performed to prevent one neonate with respiratory morbidity. Therefore, in our opinion, fear of early term labour and workforce disutility is no argument for scheduling elective CSs <39+0  weeks.

Breastfeeding Intensity and Exclusivity of Early Term Infants at Birth and 1 Month

Objective: To examine breastfeeding exclusivity and intensity of early term (ET) infants, born at 37-38 weeks, and term infants, born at 39-41 weeks, during the postpartum hospitalization and the first month of life. Materials and Methods: This was a prospective cohort study of 358 mothers of ET and term infants during the first 72 hours after birth and at 1 month of age. Logistic analysis was used to calculate unadjusted and adjusted odds ratios (aORs) and control for confounding variables. Results: ET infants had significantly lower breastfeeding in the first hour (aOR = 0.43, 95% confidence interval [CI] = 0.21-0.87), lower exclusive breastfeeding in the hospital and at 1 month (aOR = 0.46, 95% CI = 0.27-0.71 and aOR = 0.40, 95% CI = 0.22-0.71), and lower rates of high breastfeeding intensity in the hospital and at 1 month (aOR = 0.39, 95% CI = 0.22-0.71 and aOR = 0.33, 95% CI = 0.15-0.72), after controlling for confounding variables. ET infants had more emergency room (ER) visits in the first month (OR = 7.6, 95% CI = 1.01-60.6), and all ET infants who had ER visits were exclusively breastfed. Conclusions: ET infants had lower breastfeeding in the hospital and at 1 month. They should be regarded as a group at risk for breastfeeding challenges and infant morbidity.

Asthma in 9-year-old children of subfertile couples is not associated with in vitro fertilization procedures

Asthma is a chronic reversible obstructive airway disease, which is common among children and leads to respiratory impairment. Studies showed that asthma is more common among children born after in vitro fertilization (IVF) than among spontaneously conceived children. However, it is unknown which component of the IVF procedure contributes to this putative link. Therefore, the aim of this prospective follow-up study was to differentiate the possible effect of ovarian hyperstimulation from that of the in vitro culture procedure on asthma and rhinitis in 9-year-old children conceived with IVF. The study comprised three groups of singletons: (I) conceived with ovarian hyperstimulation-IVF (COH-IVF, n = 95); (II) conceived with modified natural cycle-IVF (MNC-IVF, n = 48); and (III) naturally conceived to subfertile couples (Sub-NC, n = 68). Parents filled out the validated Dutch version of the asthma questionnaire of the International Study of Asthma and Allergies. Asthma prevalence in the groups did not differ: COH-IVF n = 8 (8%); MNC-IVF n = 0 (0%); and Sub-NC n = 4 (6%). Adjustment for confounders did not alter the results.Conclusion: Neither ovarian hyperstimulation nor the in vitro culture procedure was associated with asthma and rhinitis at 9 years. IVF children had a similar prevalence of asthma compared with children conceived naturally by subfertile couples.Trial registration: ISRCTN76355836 What is Known: • An increased risk for asthma has been observed in children born after in vitro fertilization at preschool and school age. • The association between IVF and asthma may be partly explained by parental subfertility. What is New: • IVF children do not have a higher prevalence of asthma than children of subfertile couples conceived naturally. • Ovarian hyperstimulation used in IVF is not associated with asthma in 9-year-old children of subfertile couples.

Lung function in adults born preterm

Very preterm birth, before the gestational age (GA) of 32 weeks, increases the risk of obstructed airflow in adulthood. We examined whether all preterm births (GA<37 weeks) are associated with poorer adult lung function and whether any associations are explained by maternal, early life/neonatal, or current life factors. Participants of the ESTER Preterm Birth Study, born between 1985 and 1989 (during the pre-surfactant era), at the age of 23 years participated in a clinical study in which they performed spirometry and provided detailed medical history. Of the participants, 139 were born early preterm (GA<34 weeks), 239 late preterm (GA: 34-<37 weeks), and 341 full-term (GA≥37 weeks). Preterm birth was associated with poorer lung function. Mean differences between individuals born early preterm versus full-term were -0.23 standard deviation (SD) (95% confidence interval (CI): -0.40, -0.05)) for forced vital capacity z-score (zFVC), -0.44 SD (95% CI -0.64, -0.25) for forced expiratory volume z-score (zFEV1), and -0.29 SD (95% CI -0.47, -0.10) for zFEV1/FVC. For late preterm, mean differences with full-term controls were -0.02 SD (95% CI -0.17, 0.13), -0.12 SD (95% CI -0.29, 0.04) and -0.13 SD (95% CI -0.29, 0.02) for zFVC, zFEV1, and zFEV1/FVC, respectively. Examination of finer GA subgroups suggested an inverse non-linear association between lung function and GA, with the greatest impact on zFEV1 for those born extremely preterm. The subgroup means were GA<28 weeks: -0.98 SD; 28-<32 weeks: -0.29 SD; 32-<34 weeks: -0.44 SD; 34-<36 weeks: -0.10 SD; 36-<37weeks: -0.11 SD; term-born controls (≥37weeks): 0.02 SD. Corresponding means for zFEV1/FVC were -1.79, -0.44, -0.47, -0.48, -0.29, and -0.02. Adjustment for maternal pregnancy conditions and socioeconomic and lifestyle factors had no major impact on the relationship. Preterm birth is associated with airflow limitation in adult life. The association appears to be attributable predominantly to those born most immature, with only a modest decrease among those born preterm at later gestational ages.

The association of prenatal risk factors with childhood asthma

Objective: The purpose of the study was to examine the relationship of maternal complications during pregnancy and prenatal exposures with childhood asthma among low-income families in Karachi, Pakistan. Methods: Parents/guardians of children with and without asthma visiting a charity hospital were enrolled. Information about prenatal and perinatal exposures was collected. Univariable and multiple stepwise logistic regression analysis were conducted to explore the relationship of socio-demographic, maternal complications during pregnancy, access to prenatal care, and exposure to animals and pests while pregnant with childhood asthma. Results: Maternal symptoms of nocturnal cough (adjusted OR [aOR = 2.87, 95% CI = 1.60-5.14) and wheezing (aOR = 5.57, 95% CI = 2.32-13.37) during pregnancy significantly increased the odds of childhood asthma. The family history of asthma or hay fever, also elevated the odds of childhood asthma (adjusted OR [aOR] = 5.86 (3.03-11.34). The odds of asthma among children whose mothers received prenatal care by Dai, an unskilled health worker, were significantly elevated. Lastly, prenatal exposure to rats/mice and contact with goats while pregnant was significantly associated with childhood asthma. Whereas, prenatal exposure to cows/cattle reduces the odds of childhood asthma. Conclusions: This study identified important maternal and prenatal risk factors for childhood asthma, the majority of which are avoidable. Appropriate steps are needed to create awareness about the prenatal risk factors in this population.

Maternal Black Race and Persistent Wheezing Illness in Former Extremely Low Gestational Age Newborns: Secondary Analysis of a Randomized Trial

OBJECTIVE

To evaluate the relationship between maternal self-reported race/ethnicity and persistent wheezing illness in former high-risk, extremely low gestational age newborns, and to quantify the contribution of socioeconomic, environmental, and biological factors on this relationship.

STUDY DESIGN

We assessed persistent wheezing illness determined at 18-24 months corrected (for prematurity) age in survivors of a randomized trial. Parents/caregivers were surveyed for wheeze and inhaled asthma medication use quarterly to 12 months, and at 18 and 24 months. We used multivariable analysis to evaluate the relationship of maternal race to persistent wheezing illness, and identified mediators for this relationship via formal mediation analysis.

RESULTS

Of 420 infants (25.2 ± 1.2 weeks of gestation and 714 ± 166 g at birth, 57% male, 34% maternal black race), 189 (45%) had persistent wheezing illness. After adjustment for gestational age, birth weight, and sex, infants of black mothers had increased odds of persistent wheeze compared with infants of nonblack mothers (OR = 2.9, 95% CI 1.9, 4.5). Only bronchopulmonary dysplasia, breast milk diet, and public insurance status were identified as mediators. In this model, the direct effect of race accounted for 69% of the relationship between maternal race and persistent wheeze, whereas breast milk diet, public insurance status, and bronchopulmonary dysplasia accounted for 8%, 12%, and 10%, respectively.

CONCLUSIONS

Among former high-risk extremely low gestational age newborns, infants of black mothers have increased odds of developing persistent wheeze. A substantial proportion of this effect is directly accounted for by race, which may reflect unmeasured environmental influences, and acquired and innate biological differences.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01022580.

Does the sex of the preterm baby affect respiratory outcomes?

Being born very preterm is associated with later deficits in lung function and an increased rate of respiratory symptoms compared with term-born children. The rates of early respiratory infections are higher in very preterm-born subjects, which may independently lead to deficits in lung function in later life. As with very preterm-born children, deficits in lung function, increased respiratory symptoms and an increased risk of respiratory infections in early life are observed in late -preterm-born children. However, the rates of respiratory symptoms are lower compared with very preterm-born children. There is some evidence to suggest that respiratory outcomes may be improving over time, although not all the evidence suggests improvements. Male sex appears to increase the risk for later adverse respiratory illness. Although not all studies report that males have worse long-term respiratory outcomes than females. It is essential that preterm-born infants are followed up into childhood and beyond, and that appropriate treatment for any lung function deficits and respiratory symptoms is prescribed if necessary. If these very preterm-born infants progress to develop chronic obstructive airway disease in later life then the impact, not only on the individuals, but also the economic impact on healthcare services, is immense.

Educational aims

To report the effect of the sex of the preterm baby on respiratory outcomes.To explore the short- and long-term respiratory outcomes of preterm birth.

Examining Early Childhood Health Outcomes of Children Born Late Preterm in Urban Manitoba

Objective The late preterm population [34-36 weeks gestational age (GA)] is known to incur increased morbidity in the infancy stage compared to the population born at term (39-41 weeks GA). This study aimed to examine the health of these children during their early childhood years, with specific attention to the role of socioeconomic status. Methods A retrospective cohort study was conducted using data from the Manitoba Centre for Health Policy, including all live-born children born at 34-36 and 39-41 weeks GA in urban Manitoba between 2000 and 2005 (n = 28,100). Multivariable logistic regression was used to examine the association of GA with early childhood morbidity after controlling for maternal, child and family level variables. Results The late preterm population was found to have significantly greater adjusted odds of lower respiratory tract infections in the preschool years (aOR = 1.59 [1.24, 2.04]) and asthma at school age (aOR = 1.33 [1.18, 1.47]) compared to the population born at term. The groups also differed in health care utilization at ages 4 (aOR = 1.19 [1.06,1.34]) and 7 years (aOR = 1.24 [1.09, 1.42]). Additional variables associated with poor outcomes suggest that social deprivation and GA simultaneously have a negative impact on early childhood development. Conclusions for Practice Adjustment for predictors of poor early childhood development, including socioeconomic status, were found to attenuate but not eliminate health differences between children born late preterm and children born at term. Poorer health outcomes that extend into childhood have implications for practice at the population level and suggest a need for further follow-up post discharge.

Asthma and atopic dermatitis after early-, late-, and post-term birth

OBJECTIVE

To assess the incidence and risk factors of asthma and atopic dermatitis by seven years of age after early-term (ET) (37⁺⁰ -38⁺⁶ weeks), full-term (FT) (39⁺⁰ -40⁺⁶ weeks), late-term (LT) (41⁺⁰ -41⁺⁶ weeks), and especially post-term (PT) (≥42 weeks) birth.

METHODS

Altogether, 965 203 infants born between 1991 and 2008 in Finland were investigated in ET, FT, LT, and PT groups. Data on asthma medication reimbursement and hospital visits for atopic dermatitis were retrieved from national health databases.

RESULTS

The frequencies of asthma medication reimbursement in the ET, FT, LT, and PT groups were 4.5%, 3.7%, 3.3%, and 3.2%, respectively. Hospital visits due to atopic dermatitis were most common after PT birth. Compared with FT births, ET births were associated with an increased risk of asthma (adjusted odds ratio (aOR), 95% confidence interval (CI) 1.20, 1.17-1.23), while LT (aOR, 95%CI 0.91, 0.89-0.93) births and PT (aOR, 95%CI 0.87, 0.83-0.92) births decreased this risk. PT birth (aOR, 95%CI 1.06, 1.01-1.10) predicted atopic dermatitis. From a population point of view, the most relevant risk factors for asthma were male sex, ET birth, smoking during pregnancy and birth by elective cesarean section, and for atopic dermatitis male sex, first delivery, birth in a level II hospital and birth by cesarean section.

CONCLUSIONS

Early-term birth was a predictor of asthma, and PT birth was associated with atopic dermatitis. Counseling against smoking and following strict indications for planned ET deliveries and cesarean sections may be means to reduce the risk of later asthma.

Lung Development and Aging

The onset of chronic obstructive pulmonary disease (COPD) can arise either from failure to attain the normal spirometric plateau or from an accelerated decline in lung function. Despite reports from numerous big cohorts, no single adult life factor, including smoking, accounts for this accelerated decline. By contrast, five childhood risk factors (maternal and paternal asthma, maternal smoking, childhood asthma and respiratory infections) are strongly associated with an accelerated rate of lung function decline and COPD. Among adverse effects on lung development are transgenerational (grandmaternal smoking), antenatal (exposure to tobacco and pollution), and early childhood (exposure to tobacco and pollution including pesticides) factors. Antenatal adverse events can operate by causing structural changes in the developing lung, causing low birth weight and prematurity and altered immunological responses. Also important are mode of delivery, early microbiological exposures, and multiple early atopic sensitizations. Early bronchial hyperresponsiveness, before any evidence of airway inflammation, is associated with adverse respiratory outcomes. Overlapping cohort studies established that spirometry tracks from the preschool years to late middle age, and those with COPD in the sixth decade already had the worst spirometry at age 10 years. Alveolar development is now believed to continue throughout somatic growth and is adversely impacted by early tobacco smoke exposure. Genetic factors are also important, with genes important in lung development and early wheezing also being implicated in COPD. The inescapable conclusion is that the roots of COPD are in early life, and COPD is a disease of childhood adverse factors interacting with genetic factors.

Maternal anemia during pregnancy and slightly higher risk of asthma in male offspring

AIM

We aimed to determine whether maternal hemoglobin levels or anemia during pregnancy are associated with the development of asthma among offspring.

METHODS

Data were retrieved from the birth register database of Kuopio University Hospital between 1989 and 2007 (n = 38 381). Hemoglobin levels were measured during three trimesters of pregnancy and anemia was defined according to the World Health Organization criteria. The prevalence of asthma was determined from the register of reimbursement for medication for asthma at the Finnish Social Security Institution. Cox proportional hazard regression analysis was performed to evaluate the possible associations between prenatal factors and development of asthma ever.

RESULTS

A total of 8198 (21.4%) women had anemia at some stage of pregnancy. Mild maternal anemia during the first trimester was associated with an increased risk of asthma among male offspring (adjusted hazard ratio, 1.46; 95% confidence interval, 1.11-1.94) compared with those with normal maternal hemoglobin levels. This finding remained significant also after applying the Bonferroni correction.

CONCLUSION

Male offspring with maternal anemia during the first trimester of pregnancy had significantly more asthma ever than the offspring of women with normal hemoglobin levels during pregnancy. These findings were not strong but suggest possible sex-specific effects of maternal health on prenatal programming and future risk of asthma.

Sex-specific impact of asthma during pregnancy on infant gut microbiota

Asthma during pregnancy is associated with retardation of fetal growth in a sex-specific manner. Lactobacilli microbes influence infant growth. This study aimed to determine whether lactobacilli and other microbes are reduced in the gut of infants born to an asthmatic mother, and whether this differs by the sex of the infant.

Mother-infant pairs (N=1021) from the Canadian Healthy Infant Longitudinal Development full-term cohort were studied. The abundance of infant faecal microbiota at 3–4 months, profiled by gene sequencing, was compared between both women with and without asthma treatment during pregnancy. Infant sex, maternal ethnicity, pre-pregnancy overweight and atopy status, birth mode, breastfeeding status and intrapartum antibiotic treatment were tested as covariates.

Independent of birth mode and other covariates, male, Caucasian infants born to women with prenatal asthma harboured fewer lactobacilli in the gut at 3–4 months of age. If asthmatic mothers had pre-pregnancy overweight, the abundance of Lactobacillus in males was further reduced in the infant gut, whereas the microbiota of female infants was enriched with Bacteroidaceae. Similar differences in infant gut microbial composition according to maternal prenatal asthma status were also more evident among women with food or environmental allergies.

Gut lactobacilli were less abundant in male infants, but Bacteroidaceae were more abundant in female infants at 3–4 months of age, following maternal asthma during pregnancy.

Gut lactobacilli are less abundant at 3–4 months in male but not female infants following maternal prenatal asthmahttp://ow.ly/jXnl30fU9xH

Adults born preterm: a review of general health and system-specific outcomes

In this review of 126 publications, we report that an overwhelming majority of adults born at preterm gestations remain healthy and well. However, a small, but a significant fraction of them remain at higher risk for neurological, personality and behavioural abnormalities, cardio-pulmonary functional limitations, systemic hypertension and metabolic syndrome compared to their term-born counterparts. The magnitude of increased risk differed across organ systems and varied across reports. The risks were proportional to the degree of prematurity at birth and seemed to occur more frequently among preterm infants born in the final two decades of the 20th century and later. These findings have considerable public health and clinical practice relevance.

CONCLUSION

Preterm birth needs to be considered a chronic condition, with a slight increase in the risk for long-term morbidities among adults born preterm. Therefore, obtaining a history of gestational age and weight at birth should be a routine part of care for patients of all age groups.

Evaluation of pulmonary functions in preschool children born late-preterm

AIM

The aim of this study was to evaluate the pulmonary functions of preschool children born late-preterm.

MATERIAL AND METHODS

Children aged between 3-7 years who were born at 340/7-366/7 weeks' gestation represented the target sample. Patients with a diagnosis of congenital cardiac, pulmonary and/or muscle diseases were excluded. Respiratory symptoms were evaluated using the modified asthma predictive index and International Study of Asthma and Allergies in Childhood criteria for children aged under and over 6 years, respectively. Skin prick tests were performed. Age-matched healthy controls were chosen according to the criteria proposed by the American Thoracic Society. Lung functions were evaluated using impulse oscillometry study in both groups. Data were recorded in the SPSS program.

RESULTS

A total of 139 late-preterms and 75 healthy controls participated in the study. The mean gestational week of the late-preterms was 35.3±0.9 weeks. The main admission diagnosis to neonatal intensive care unit was respiratory distress. In the postdischarge period, 54.1% were hospitalized for pulmonary infections at least once, and 57.8% were passive smoking currently. Aeroallergen sensitivity was detected as 25.8% in the late-preterm group; 34.5% and 15.1% were diagnosed as having asthma and non-asthmatic atopy, respectively. Impulse oscillometry study parameters of R5, R10, and Z5 were higher and X10 and X15 were lower in late-preterms than in controls (p<0.05). Late-preterms with and without respiratory distress in the postnatal period revealed no statistical differences for any parameters.

CONCLUSIONS

Our findings suggest that presence of increased peripheral airway resistance in late-preterms as compared to term-born controls.

The Kingston Allergy Birth Cohort: Exploring parentally reported respiratory outcomes through the lens of the exposome

BACKGROUND

The Kingston Allergy Birth Cohort (KABC) is a prenatally recruited cohort initiated to study the developmental origins of allergic disease. Kingston General Hospital was chosen for recruitment because it serves a population with notable diversity in environmental exposures relevant to the emerging concept of the exposome.

OBJECTIVE

To establish a profile of the KABC using the exposome framework and examine parentally reported respiratory symptoms to 2 years of age.

METHODS

Data on phase 1 of the cohort (n = 560 deliveries) were compiled, and multivariate Cox proportional hazards regression models were used to determine associations with respiratory symptoms.

RESULTS

The KABC exhibits diversity within the 3 exposome domains of general external (socioeconomic status, rural or urban residence), specific external (cigarette smoke, breastfeeding, mold or dampness), and internal (respiratory health, gestational age), as well as significant associations between exposures from different domains. Significant associations emerged between parental reports of wheeze or cough without a cold and prenatal cigarette smoke exposure, mold or dampness in the home, and the use of air fresheners in the early-life home environment. Breastfeeding, older siblings, and increased gestational age were associated with decreased respiratory symptoms.

CONCLUSION

The KABC is a unique cohort with diversity that can be leveraged for exposomics-based studies. This study found that all 3 domains of the exposome had effects on the respiratory health of KABC children. Ongoing studies using phase 1 of the KABC continue to explore the internal exposome through allergy skin testing and epigenetic analyses and the specific external domain through in-home environmental analyses, air pollution modeling, and ultimately potential convergences within and among domains.

Lower respiratory tract disorder hospitalizations among children born via elective early-term delivery

OBJECTIVE

We evaluated the hypothesis that elective early-term delivery increases the risk of childhood lower respiratory tract disorder hospitalization.

METHODS

Children born via early-term elective inductions were compared to full- or late-term elective inductions in a retrospective cohort study using Washington State birth certificate and hospital discharge data. Outcomes were the odds of lower respiratory disorder hospitalization before age five and cause specific odds ratios for asthma, bronchiolitis, bronchitis, and pneumonia. In addition, a subgroup analysis excluding infants with perinatal complications was conducted.

RESULTS

Electively induced early-term children were at significantly increased risk of hospitalization before age five for lower respiratory disorders compared to similar full- or late-term children (adjusted OR: 1.31, 95% CI: 1.11-1.55). Bronchiolitis was the only cause-specific outcome with a statistically significant increase in odds of hospitalization, though comparable increases were found for the less common diagnoses of asthma (adjusted OR: 1.39, 95% CI: 0.93-2.08) and pneumonia (adjusted OR: 1.27, 95% CI: 0.99-1.64). Excluding infants with perinatal complications did not alter the results.

CONCLUSIONS

There was an association between electively induced early-term delivery and hospitalization for lower respiratory tract disorders before age five. This reinforces policies discouraging elective early-term delivery.