Birth weight and subsequent risk of asthma: a systematic review and meta-analysis

No relationship found between dental fluctuating asymmetry, birthweight, and birth term in two modern North American samples

OBJECTIVE

Deciduous dental crowns primarily develop during gestation and early infancy and embody early life stress exposures. Composite measures of dental fluctuating asymmetry (DFA) generated from the deciduous teeth may therefore indicate cumulative gestational stress in developmental origins of health and disease (DOHaD) studies. This study examines whether higher composite measures of deciduous DFA are associated with low birthweight and prematurity, two aspects of birth phenotype consistently associated with increased morbidity and mortality risks in adulthood.

SUBJECTS AND METHODS

We evaluated associations between composite deciduous DFA, birthweight, and birth term in two contemporary North American samples: an autopsy sample from New Mexico (n = 94), and sample from a growth cohort study in Burlington, Ontario (n = 304). Dental metric data for each sample was collected from postmortem CT scans and dental casts, respectively. Composite DFA was estimated using buccolingual (BL) and mesiodistal (MD) crown diameters from paired deciduous teeth.

RESULTS

Contrary to expectations, the results of linear regression indicated no significant relationship between birthweight and DFA, or birth term and DFA, in either sample.

CONCLUSIONS

Deciduous DFA does not predict aspects of birth phenotype associated with gestational stress. Birthweight and birth term are plastic relative to the more developmentally stable deciduous dentition, which may only subtly embody early life stress. We suggest that deciduous DFA should be utilized with caution in DOHaD studies until its relationship with gestational stress is clarified.

Association between type 2 inflammatory diseases and neurodevelopmental disorders in low-birth-weight children and adolescents

Background

Evidence of the association of certain neurodevelopmental disorder with specific type 2 inflammatory (T2) disease has been found. However, the association of various neurodevelopmental disorders with T2 diseases as a whole remains unclear in low-birth-weight (LBW) infants.

Objective

To evaluate the association of type 2 inflammatory (T2) diseases with intellectual disability (ID), autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and learning disability (LD) in LBW children and adolescents.

Methods

The study sample was derived from 2005 to 2018 National Health Interview Survey sample child files. LBW children and adolescents aged 3-17 were included. History of T2 diseases (including asthma and atopic dermatitis) and four neurodevelopmental disorders were reported by adults in families. The relationship between T2 diseases and the risk of four neurodevelopmental disorders was investigated through multiple-weighted logistic regression. Age, sex, race/ethnicity, region, highest education in family and ratio of family income to the poverty threshold were adjusted as covariates for model estimation. Subgroup analyses were conducted by age stratification (3-11 and 12-17 years), sex (male and female), and race (white and non-white).

Results

11,260 LBW children aged 3-17 years [mean age (SE), 9.73 (0.05) years] were included, in which 3,191 children had T2 diseases. History of T2 diseases was associated with an increased risk of neurodevelopmental disorders, with an OR of 1.35 (95% CI, 0.99-1.84) for ID, 1.47 (95% CI, 1.05-2.05) for ASD, 1.81 (95% CI, 1.51-2.16) for ADHD, and 1.74 (95% CI, 1.49-2.04) for LD following the adjustment of all the covariates. The correlations between T2 disorders and each of the four neurodevelopmental disorders were significantly different by sex and race (all P for interaction < 0.001), and no differences were found in age stratification (all P for interaction > 0.05).

Conclusion

In a nationally representative sample of children, we found a significant association of T2 diseases with ASD, ADHD, and LD, even after adjusting for demographic baseline. We also found that the association of T2 disease with neurodevelopmental disorders differed between sex and race. Further investigation is needed to evaluate causal relationships and elucidate their potential mechanisms.

Effects of size at birth on health, growth and developmental outcomes in children up to age 18: an umbrella review

BACKGROUND

Size at birth, an indicator of intrauterine growth, has been studied extensively in relation to subsequent health, growth and developmental outcomes. Our umbrella review synthesises evidence from systematic reviews and meta-analyses on the effects of size at birth on subsequent health, growth and development in children and adolescents up to age 18, and identifies gaps.

METHODS

We searched five databases from inception to mid-July 2021 to identify eligible systematic reviews and meta-analyses. For each meta-analysis, we extracted data on the exposures and outcomes measured and the strength of the association.

FINDINGS

We screened 16 641 articles and identified 302 systematic reviews. The literature operationalised size at birth (birth weight and/or gestation) in 12 ways. There were 1041 meta-analyses of associations between size at birth and 67 outcomes. Thirteen outcomes had no meta-analysis.Small size at birth was examined for 50 outcomes and was associated with over half of these (32 of 50); continuous/post-term/large size at birth was examined for 35 outcomes and was consistently associated with 11 of the 35 outcomes. Seventy-three meta-analyses (in 11 reviews) compared risks by size for gestational age (GA), stratified by preterm and term. Prematurity mechanisms were the key aetiologies linked to mortality and cognitive development, while intrauterine growth restriction (IUGR), manifesting as small for GA, was primarily linked to underweight and stunting.

INTERPRETATION

Future reviews should use methodologically sound comparators to further understand aetiological mechanisms linking IUGR and prematurity to subsequent outcomes. Future research should focus on understudied exposures (large size at birth and size at birth stratified by gestation), gaps in outcomes (specifically those without reviews or meta-analysis and stratified by age group of children) and neglected populations.

PROSPERO REGISTRATION NUMBER

CRD42021268843.

Relationship Between Birth Weight and Asthma Diagnosis: A Cross-Sectional Survey Study Based on the National Survey of Children's Health in the U.S

OBJECTIVE

To assess the association between birth weight and childhood asthma risk using data from the 2019-2020 National Survey of Children's Health database.

DESIGN

Cross-sectional study.

SETTING

The USA.

PATIENTS

A representative cohort of American children.

EXPOSURE

The exposure of this study was birth weight regardless of gestational age. Birth weight was divided into three groups: <1500 g, 1500-2500 g and >2500 g.

MAIN OUTCOME MEASURES

Primary outcomes were parent-reported diagnosis of asthma.

METHOD

The Rao-Scott χ2 test was used to compare the groups. The main analyses examined the association between birth weight and parent-report asthma in children using univariable and multivariable logistic models adjusting for preterm birth, age, sex, race, family poverty, health insurance, smoking, maternal age. Subgroup analysis was performed based on interaction test.

RESULTS

A total of 60 172 children aged 3-17 years were enrolled in this study; of these, 5202 (~8.6%) had asthma. Children with asthma were more likely to be born preterm, with low birth weight (LBW) or very LBW (VLBW). The incidence of asthma was the highest in VLBW children at 20.9% and showed a downward trend with an increase in birth weight class, with rates of 10.7% and 8.1% in the LBW and normal birthweight groups, respectively. Children with VLBW (OR 1.97; 95% CI 1.29 to 3.01) had higher odds of developing asthma in the adjusted analysis model. However, VLBW was only shown to be a risk factor for asthma among Hispanics, black/African-Americans and children between the ages of 6 and 12 years, demonstrating racial and age disparities.

CONCLUSIONS

VLBW increases the risk of childhood asthma; however, racial and age disparities are evident.

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.

Altitude Modifies the Effect of Parity on Birth Weight/Length Ratio: A Study Comprising 2,057,702 Newborns between 1984 and 2020 in Austria

(1) Background: Lower birth weight among newborns in higher altitudes has been well documented in previous literature. Several possible causes for this phenomenon have been investigated, including biophysiological adaptation, epigenetic or genetic mechanisms or lifestyle changes. This is the first study to show the effect modification of altitude and parity on the birth weight length ratio (BWLR) in women resident in moderate altitudes compared to a low sea level.; (2) Methods: This population-based study obtained data on altitude (0-300, 300-500, 500-700,700-900, >900 m), parity (1, 2, …, 7, 8/9), birth weight and length on all births in Austria between 1984 and 2020 from birth certificates provided by Statistics Austria. The BWLR was calculated, and the effect of moderate altitude and parity was estimated using multivariable linear mixed models adjusting for predefined variables. Sub-group regression analyses were conducted by altitude group. (3) Results: Data on 2,057,702 newborns from 1,280,272 mothers were analyzed. The effect of parity on BWLR, as indicated by the difference of BWLR between the first- and second-born infants, ranged between 1.87 to 2.09 g per centimeter across all altitude groups. Our analyses found that the effect of parity on BWLR diminished from parity three onwards at altitude 0-300, whilst the effect of parity on BWLR continued to increase at higher than 300 m and was most notable in the highest altitude group >900 m. (4) Conclusions: Findings from our study indicated that the negative effect of increasing altitude on BWLR was deprived for newborns of higher parity. It shows that the residential altitude can modify the effect of parity on BWLR.

Early-Life Weight Status and Risk of Childhood Asthma or Recurrent Wheeze in Preterm and Term Offspring

BACKGROUND

Excessive weight is associated with the development of childhood asthma. However, trends among preterm and term offspring may differ.

OBJECTIVE

To assess whether the association of longitudinal weight for age (WFA) and odds of asthma/recurrent wheeze in early life differs between children born preterm and those born at term.

METHODS

This study used prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial. Children (n = 804) were followed-up and anthropometric measurements, including WFA, were taken at birth and annually until the age of 6 years. The primary outcome was asthma/recurrent wheeze by age 3 and 6 years.

RESULTS

Among the offspring, 71 (8.8%) were premature. In all the children, the odds of asthma/recurrent wheeze increased by 15% (adjusted odds ratio [aOR], 1.15; 95% CI, 1.10-1.20; P < .001) by age 3 years and 9% (aOR, 1.09; 95% CI, 1.07-1.11; P < .001) by age 6 years for each unit increase in WFA z score. Odds were different between term and preterm offspring (Pinteraction < .001). In term offspring, the odds of having asthma/recurrent wheeze by age 3 and 6 years increased by 22% and 15%, respectively (aOR, 1.22, 95% CI, 1.16-1.27, P < .001, and aOR, 1.15, 95% CI, 1.11-1.18, P < .001). In preterm offspring, by age 3 years, odds of asthma/recurrent wheeze decreased by 10% for each unit increase in WFA z score (aOR, 0.90; 95% CI, 0.81-0.99; P = .030) and decreased by 27% by age 6 years (aOR, .73; 95% CI, 0.61-0.86; P < .001).

CONCLUSIONS

During early life, increasing standardized WFA is associated with higher odds of asthma/recurrent wheeze in term children. In contrast, in preterm children, a higher standardized WFA during catch-up growth may decrease the odds of asthma/recurrent wheeze associated with prematurity.

Identifying risk factors for COPD and adult-onset asthma: an umbrella review

BACKGROUND

COPD and adult-onset asthma (AOA) are the most common noncommunicable respiratory diseases. To improve early identification and prevention, an overview of risk factors is needed. We therefore aimed to systematically summarise the nongenetic (exposome) risk factors for AOA and COPD. Additionally, we aimed to compare the risk factors for COPD and AOA.

METHODS

In this umbrella review, we searched PubMed for articles from inception until 1 February 2023 and screened the references of relevant articles. We included systematic reviews and meta-analyses of observational epidemiological studies in humans that assessed a minimum of one lifestyle or environmental risk factor for AOA or COPD.

RESULTS

In total, 75 reviews were included, of which 45 focused on risk factors for COPD, 28 on AOA and two examined both. For asthma, 43 different risk factors were identified while 45 were identified for COPD. For AOA, smoking, a high body mass index (BMI), wood dust exposure and residential chemical exposures, such as formaldehyde exposure or exposure to volatile organic compounds, were amongst the risk factors found. For COPD, smoking, ambient air pollution including nitrogen dioxide, a low BMI, indoor biomass burning, childhood asthma, occupational dust exposure and diet were amongst the risk factors found.

CONCLUSIONS

Many different factors for COPD and asthma have been found, highlighting the differences and similarities. The results of this systematic review can be used to target and identify people at high risk for COPD or AOA.

Small vulnerable newborns-big potential for impact

Despite major achievements in child survival, the burden of neonatal mortality has remained high and even increased in some countries since 1990. Currently, most neonatal deaths are attributable to being born preterm, small for gestational age (SGA), or with low birthweight (LBW). Besides neonatal mortality, these conditions are associated with stillbirth and multiple morbidities, with short-term and long-term adverse consequences for the newborn, their families, and society, resulting in a major loss of human capital. Prevention of preterm birth, SGA, and LBW is thus critical for global child health and broader societal development. Progress has, however, been slow, largely because of the global community's failure to agree on the definition and magnitude of newborn vulnerability and best ways to address it, to frame the problem attractively, and to build a broad coalition of actors and a suitable governance structure to implement a change. We propose a new definition and a conceptual framework, bringing preterm birth, SGA, and LBW together under a broader umbrella term of the small vulnerable newborn (SVN). Adoption of the framework and the unified definition can facilitate improved problem definition and improved programming for SVN prevention. Interventions aiming at SVN prevention would result in a healthier start for live-born infants, while also reducing the number of stillbirths, improving maternal health, and contributing to a positive economic and social development in the society.

Early origins of metabolic and overall health in young adults: An outcome-wide analysis in a general cohort population

INTRODUCTION

Long-term consequences of impaired fetal growth are well documented for cardiometabolic outcomes. We propose an outcome-wide analysis of the association between birth weight (BW) and long-term health in a large contemporary adult cohort.

METHODS

The study included 73,315 participants under 60 years with a reliable BW from the French nationwide Constances cohort. Low and high BW (LBW/HBW) were defined as BW<10th and >90th of sex-specific percentiles. Associations between BW and outcomes were analyzed with a sex-stratified modified Poisson regression adjusted for the participant's age, maternal health history, geographical origins, and parents' occupation.

RESULTS

Mean BW (10^th -90^th percentile) was 3390 g (2800-4000) for men and 3247g (2680-3820) for women. In men, LBW was associated with (RR [CI95]): fasting glucose impairment (1.33 [1.16;1.52]); hypertriglyceridemia (1.27 [1.17;1.37]); high blood pressure (HBP) (1.15 [1.07;1.24]); non-alcoholic fatty liver disease NAFLD (1.13 [1.02;1.24]); high LDL-cholesterol (1.12 [1.05;1.21]); anxiety (1.12 [1.01;1.24]) and depression (1.09 [1.00;1.18]). HBW was associated with obesity (1.21 [1.08;1.35]). In women, LBW was associated with fasting glucose impairment (1.31 [1.12;1.54]); HBP (1.27 [1.16;1.4]); hypertriglyceridemia (1.20 [1.05;1.36]); anxiety (1.10 [1.03;1.17]); and asthma (1.09 [1;1.19}). HBW was associated with obesity (1.24 [1.13;1.36]) and NAFLD (1.20 [1.06;1.37). LBW and HBW were associated with a lesser likelihood of tertiary education attainment in both sexes. Participants' education level was a significant partial mediator of the association between LBW and outcomes.

CONCLUSION

Extreme BW is associated with long-term health. It should be considered in the personalized prevention of cardiometabolic, respiratory, and mental health conditions in adulthood, especially in socio-economically disadvantaged populations.

Non-linear association of birth weight with lung function and risk of asthma: A population-based study

Background

The impact of birth weight on lung function and risk of asthma remains contentious. Our aim was to investigate the specific association of birth weight with lung function and the risk of asthma in children.

Methods

We performed cross-sectional analyses of 3,295 children aged 6-15 years who participated in the 2007-2012 National Health and Nutrition Examination Survey (NHANES). After controlling for potential covariates other than gestational diabetes, maternal asthma and obesity, the linear and non-linear associations of birth weight with lung function metrics and the risk of asthma were evaluated by a generalized linear model and generalized additive model, respectively.

Results

We observed a non-linear association of birth weight with FEV₁ %predicted, FEV₁/FVC %predicted and FEF_{25 - 75} %predicted (P for non-linearity was 0.0069, 0.0057, and 0.0027, respectively). Further threshold effect analysis of birth weight on lung function detected the turning point for birth weight was 3.6 kg. When the birth weight was < 3.6 kg, birth weight was significantly positively associated with all pulmonary function metrics. However, negative associations were found in FEV₁ %predicted, FEV₁/FVC %predicted and FEF_{25 - 75} %predicted when the birth weight was ≥3.6 kg. These results were consistent in the stratified and sensitivity analyses. Additionally, a possible non-linear relationship was also detected between birth weight and the risk of asthma.

Conclusion

Although not all maternal factors were accounted for, our findings provided new insight into the association of birth weight with lung function. Future studies are warranted to confirm the present findings and understand the clinical significance.

Childhood overweight and obesity and abnormal birth anthropometric measures are associated with a higher prevalence of childhood asthma in pre-school age

OBJECTIVES

Childhood asthma is one of the most common non-communicable diseases in the world. Several perinatal and postnatal factors have been associated with increased risk of developing childhood asthma. The present study aims to assess whether childhood overweight and obesity and abnormal birth anthropometric measures affect the risk of developing childhood asthma in preschool age.

METHODS

In this study, 5215 preschool children at the age of 2-5 years were enrolled after applying several inclusion and exclusion criteria and they examined whether they present asthma symptoms. Non-adjusted and adjusted statistical analysis was performed to assess whether perinatal and postnatal factors increase the risk of developing childhood asthma.

RESULTS

A prevalence of 4.5% of childhood asthma was recorded. Among children diagnosed with asthma, 19.4% were affected by overweight and 13.9% were obese. Childhood overweight/obesity was indepedently associated with a 76% higher risk of childhood asthma than normal weight. Abnormal birth anthropometric measures, i.e. birth weight, length, and head circumference, were independently associated with higher odds (87%, 29%, and 23%, respectively) of childhood asthma than normal ranges.

CONCLUSIONS

This is a cross-sectional, nationally representative study which supported evidence that childhood overweight/obesity and abnormal birth anthropometric measures may independently increase the risk of childhood asthma in preschool age. Emergent health policies and strategies are recommended to promote a healthy lifestyle, preventing childhood obesity at the early stages of life.

Birth weight and long-term risk of mortality among US men and women: Results from three prospective cohort studies

Background

Weight at birth has been associated with the development of various adult diseases, but its association with mortality remains unclear.

Methods

We included 22,389 men from the Health Professionals Follow-up Study (1994-2018) and 162,231 women from the Nurses' Health Study (1992-2018) and the Nurses' Health Study II (1991-2019). The hazard ratios (HRs) of mortality according to birth weight were estimated by Cox proportional hazards regression models with adjustment for potential confounders.

Findings

Compared to women reporting a birth weight of 3.16-3.82 kg, the pooled HRs for all-cause mortality were 1.13 (95% CI, 1.08 to 1.17), 0.99 (95% CI, 0.96 to 1.02), 1.04 (95% CI, 1.00 to 1.08), and 1.03 (95% CI, 0.96 to 1.10), respectively, for women with a birth weight of <2.5, 2.5-3.15, 3.83-4.5, and >4.5 kg. In cause-specific mortality analyses, women reporting birth weight >4.5 kg had a higher risk of cancer mortality (HR=1.15, 95% CI: 1.00 to 1.31), whereas women with a birth weight <2.5 kg had an elevated risk of mortality from cardiovascular diseases (HR=1.15; 95% CI, 1.05 to 1.25) and respiratory diseases (HR=1.35; 95% CI, 1.18 to 1.54). Birth weight was unrelated to all-cause mortality among men, but cause-specific mortality analyses showed an inverse association with cardiovascular disease mortality and a positive association with cancer mortality (p for linear trend = 0.012 and 0.0039, respectively).

Interpretation

low birth weight was associated with a greater risk of cardiovascular and respiratory disease mortality among women, while large birth weight was associated with a greater cancer mortality risk in both men and women.

Funding

The National Institutes of Health grants U01-HL145386, U01-CA176726, R01-HL034594, R01-HL088521, UM-CA186107, P01-CA87969, R01-CA49449, R01-CA67262, U01-HL145386, U01-CA167552, R01-HL35464, and R24-ES028521-01 support this study.

Towards optimum smoking cessation interventions during pregnancy: a household model to explore cost-effectiveness

BACKGROUND AND AIMS

Previous economic evaluations of smoking cessation interventions for pregnant women are limited to single components, which do not in isolation offer sufficient potential impact to address smoking cessation targets. To inform the development of more appropriate complex interventions, we (1) describe the development of the Economics of Smoking in Pregnancy: Household (ESIP.H) model for estimating the life-time cost-effectiveness of smoking cessation interventions aimed at pregnant women and (2) use a hypothetical case study to demonstrate how ESIP.H can be used to identify the characteristics of optimum smoking cessation interventions.

METHODS

The hypothetical intervention was based on current evidence relating to component elements, including financial incentives, partner smoking, intensive behaviour change support, cigarettes consumption and duration of support to 12 months post-partum. ESIP.H was developed to assess the life-time health and cost impacts of multi-component interventions compared with standard National Health Service (NHS) care in England. ESIP.H considers cigarette consumption, partner smoking and some health conditions (e.g. obesity) that were not included in previous models. The Markov model's parameters were estimated based on published literature, expert judgement and evidence-based assumptions. The hypothetical intervention was evaluated from an NHS perspective.

RESULTS

The hypothetical intervention was associated with an incremental gain in quitters (mother and partner) at 12 months postpartum of 249 [95% confidence interval (CI) = 195-304] per 1000 pregnant smokers. Over the long-term, it had an incremental negative cost of £193 (CI = -£779 to 344) and it improved health, with a 0.50 (CI = 0.36-0.69) increase in quality-adjusted life years (QALYs) for mothers, partners and offspring, with a 100% probability of being cost-effective.

CONCLUSIONS

The Economics of Smoking in Pregnancy: Household model for estimating cost-effectiveness of smoking cessation interventions aimed at pregnant women found that a hypothetical smoking cessation intervention would greatly extend reach, reduce smoking and be cost-effective.

Diagnosis and management of asthma in children

Asthma is the the most common chronic respiratory condition of childhood worldwide, with around 14% of children and young people affected. Despite the high prevalence, paediatric asthma outcomes are inadequate, and there are several avoidable deaths each year. Characteristic asthma features include wheeze, shortness of breath and cough, which are typically triggered by a number of possible stimuli. There are several diagnostic challenges, and as a result, both overdiagnosis and underdiagnosis of paediatric asthma remain problematic.Effective asthma management involves a holistic approach addressing both pharmacological and non-pharmacological management, as well as education and self-management aspects. Working in partnership with children and families is key in promoting good outcomes. Education on how to take treatment effectively, trigger avoidance, modifiable risk factors and actions to take during acute attacks via personalised asthma action plans is essential.This review aimed to provide an overview of good clinical practice in the diagnosis and management of paediatric asthma. We discuss the current diagnostic challenges and predictors of life-threatening attacks. Additionally, we outline the similarities and differences in global paediatric asthma guidelines and highlight potential future developments in care. It is hoped that this review will be useful for healthcare providers working in a range of child health settings.

What is the impact of birth weight corrected for gestational age on later onset asthma: a meta-analysis

Background

Asthma is a common multifactorial disease affecting millions worldwide. The Barker hypothesis postulates an association between later onset disease risk and energy exposure in utero. Birth weight corrected for gestational age is better for measuring the infant size, which reflects energy exposure in utero. Findings on asthma and birth weight corrected for gestational age have been inconclusive. We conducted a meta-analysis to further clarify the relationship between birth weight corrected for gestational age and later onset asthma.

Methods

A systematic literature search of the PubMed, Web of Science, MEDLINE, and Scopus databases up to January 2021 was conducted. The subject terms were used as follows: “asthma”, “allerg*”, “respiratory”, “birth weight”, “gestational age”, “birth outcomes”, “intrauterine growth retardation”, and “fetal growth restriction”.

Results

We included 12 articles with data from a total of 6,713,596 people. Compared with non-SGA infants, infants small for gestation age (SGA) were not associated with an increased risk of asthma (OR = 1.07; 95% CI 0.94–1.21). However, in the subgroup analysis, we found an increased risk of later onset asthma among SGA in studies conducted in Asia, with a large sample size, and defined asthma through medical records rather than questionnaires. Large for gestational age (LGA) was not associated with an increased risk of asthma when non-LGA or appropriated for gestational age (AGA) infants were used as the reference (OR = 1.02; 95% CI 0.90–1.16; OR = 1.01; 95% CI 0.88–1.15).

Conclusion

These results indicated that neither SGA nor LGA was associated with an increased risk of asthma. However, considering the limitations of the research, these results should be interpreted with caution.

Focus on Early COPD: Definition and Early Lung Development

Chronic obstructive pulmonary disease (COPD) is a disease with high incidence rate and mortality rates worldwide. It is the third leading cause of death in the world. Nevertheless, little progress has been made in treating and preventing the disease. Under these circumstances, the concept of “early COPD” was proposed. Although this concept is not new, most health-care workers do not fully understand early COPD and tend to confuse it with mild COPD. In this review, we mainly discuss the definition of early COPD and the developmental trajectory of lung function. Although patients with early COPD have no symptoms, their lung function is already lower than that of normal people. A relatively complete definition is needed to identify this group of people. Reduced lung function is the diagnostic criterion for COPD, but lung development is a long-term dynamic process. In addition to smoking and air pollution, we should pay more attention to prenatal and childhood risk factors, for example, parents smoking, birth weight, preterm birth, mode of delivery, childhood respiratory infections and childhood asthma. Health-care workers need to be fully aware of early COPD, to reduce the morbidity of COPD and take effective measures to prevent these risk factors.

Impact of prenatal and early life environmental exposures on normal human development

The global burden and pattern of disease has changed in recent decades, with fewer early childhood deaths and longer lives complicated by chronic disease. Disruption of normal human growth and development by adverse environmental exposures, especially during foetal development and early postnatal life increase life-long risk of chronic disease. The developmental timing and method of adverse exposure determines the likely impact on health and development. While many organ systems are structurally and functionally mature at birth, the CNS, respiratory and immune systems are not and undergo prolonged periods of postnatal growth and development. As such, these organ systems are vulnerable to adverse effects of both prenatal and postnatal environmental exposures. While the precise mechanisms underlying chronic disease are unknown, epigenetic mechanisms and the induction of oxidative stress are likely to be involved. An understanding of these processes is necessary to develop mitigation strategies aimed at reducing chronic disease prevalence.

Asthma and allergies in offspring conceived by ART: a systematic review and meta-analysis

BACKGROUND

Currently, 1 in 25 children born in Australia are conceived through ARTs such as IVF and ICSI. Worldwide over 8 million children have been born after ART. There is evidence that these children are at an increased risk of congenital malformations, preterm birth, low birth weight and neonatal morbidity. However, studies on long-term health outcomes of offspring conceived after ART are lacking. Atopic disorders, such as asthma, atopic dermatitis and various allergies are increasingly common within society, and concerns have been raised that ART increases the risk of atopy amongst offspring.

OBJECTIVE AND RATIONALE

The aim of this study was to systematically summarise and quantify the risk of atopic disorders in offspring conceived with ART compared to those conceived without ART.

SEARCH METHODS

A systematic review was conducted according to the PRISMA guidelines. Several systematic searches were performed in the following international databases: Medline, Embase, Cinahl, PsychINFO, AMED, Global Health and ISI Web of Science. Search terms utilised were all terms pertaining to ART, IVF, ICSI, asthma, atopic dermatitis and allergies. The search period was 1978-2021. Included observational studies stated a primary outcome of asthma or allergies in offspring conceived after ART, with a comparison group conceived without ART. Individual studies were scored on quality and risk of bias, using the Newcastle-Ottawa scale (NOS).

OUTCOMES

There were 26 studies which met the inclusion criteria; of these, 24 studies investigated asthma in offspring conceived after ART. While 10 studies, including the two largest population-based studies, reported a significantly increased risk of asthma in offspring conceived after ART (adjusted odds ratio (aOR) range: 1.20-2.38), 14 smaller cohort studies found no difference (aOR range 0.70-1.27). In the meta-analysis of the 14 highest-quality studies (NOS ≥ 7), a modest yet significantly increased risk of asthma was demonstrated in offspring conceived after ART [risk ratio (RR) 1.28 (1.08-1.51)]. Although heterogeneity in these 14 studies was high (I2 = 85%), the removal of outliers and high weight studies significantly reduced heterogeneity (I2 = 0% and I2 = 34% respectively) while still demonstrating a significantly increased risk [RR 1.19 (1.10-1.28) and RR 1.31 (1.03-1.65), respectively]. The increased asthma risk was also observed in most subgroup and sensitivity analyses. The allergy rates were not increased in offspring conceived after ART in 9 of 12 studies (aOR range 0.60-1.30). In summary, the findings of this systematic review and meta-analysis suggest a trend towards a significantly increased risk of asthma, but not allergies, in offspring conceived after ART. There was no evidence of publication bias in the asthma studies and minimal evidence of publication bias in the allergy studies (both P > 0.05).

WIDER IMPLICATIONS

Asthma brings considerable burden to the quality of life of individuals and to society. Hence, it is of great importance to untangle potential causal pathways. Although ART use is common, knowledge about its long-term health effects is required to provide evidence-based advice to couples considering ART, and to be vigilant for any potential adverse health effects on offspring conceived after ART.

Maternal caffeine consumption during pregnancy and risk of low birth weight: a dose-response meta-analysis of cohort studies

BACKGROUND & OBJECTIVES

Earlier published studies on maternal caffeine intake during pregnancy in relation to the risk of low birth weight (LBW) (birth weight <2500 g) have indicated conflicting findings. Therefore, the present systematic review and meta-analysis was conducted to examine the association between maternal caffeine intake and risk of LBW.

METHODS

We searched for relevant articles published up to Jan 2021 through PubMed and Scopus. For this purpose, we used MESH (Medical Subject Heading) and non-MESH keywords. Cohort studies that considered maternal caffeine intake as the exposure variable and LBW as the main outcome variable were included in the systematic review. Finally, seven cohort studies were considered in this systematic review and meta-analysis.

RESULTS

Combining seven effect sizes, we found a significant positive association between maternal caffeine intake and risk of LBW (RR: 1.70; 95% CI: 1.19-2.43). We also found that each additional 100-mg per day of maternal caffeine intake was significantly associated with an increased risk of LBW (RR: 1.12; 95% CI: 1.03-1.22; P_{heterogeneity} = 0.020). In addition, nonlinear dose-response analysis showed a significant relationship (P_nonlinearity < 0.001) between maternal caffeine intake and risk of LBW.

CONCLUSIONS

In this systematic review and meta-analysis, we found a significant positive association between maternal caffeine intake and risk of LBW.

Fetal Growth Restriction and Asthma: Is the Damage Done?

Trajectories of airway remodeling and functional impairment in asthma are consistent with the notion that airway pathology precedes or coincides with the onset of asthma symptoms and may be present at birth. An association between intrauterine growth restriction (IUGR) and asthma development has also been established, and there is value in understanding the underlying mechanism. This review considers airway pathophysiology as a consequence of IUGR that increases susceptibility to asthma.

Intrauterine Growth Restriction Promotes Postnatal Airway Hyperresponsiveness Independent of Allergic Disease

Introduction: Intrauterine growth restriction (IUGR) is associated with asthma. Murine models of IUGR have altered airway responsiveness in the absence of any inflammatory exposure. Given that a primary feature of asthma is airway inflammation, IUGR-affected individuals may develop more substantial respiratory impairment if subsequently exposed to an allergen. This study used a maternal hypoxia-induced mouse model of IUGR to determine the combined effects of IUGR and allergy on airway responsiveness.

Methods: Pregnant BALB/c mice were housed under hypoxic conditions (10.5% O₂) from gestational day (GD) 11-GD 17.5 (IUGR group; term = GD 21). Following hypoxic exposure, mice were returned to a normoxic environment (21% O₂). A second group of pregnant mice were housed under normoxic conditions throughout pregnancy (Control). All offspring were sensitized to ovalbumin (OVA) and assigned to one of four treatment groups: Control – normoxic and saline challenge; IUGR – hypoxic and saline challenge; Allergy – normoxic and OVA challenge; and IUGR + Allergy – hypoxic and OVA challenge. At 8 weeks of age, and 24 h post-aerosol challenge, mice were tracheostomised for methacholine challenge and assessment of lung mechanics by the forced oscillation technique, and lungs subsequently fixed for morphometry.

Results: IUGR offspring were lighter than Control at birth and in adulthood. Both Allergy and IUGR independently increased airway resistance after methacholine challenge. The IUGR group also exhibited an exaggerated increase in tissue damping and elastance after methacholine challenge compared with Control. However, there was no incremental effect on airway responsiveness in the combined IUGR + Allergy group. There was no impact of IUGR or Allergy on airway structure and no effect of sex on any outcome.

Conclusion: IUGR and aeroallergen independently increased bronchoconstrictor response, but when combined the pathophysiology was not worsened. Findings suggest that an association between IUGR and asthma is mediated by baseline airway responsiveness rather than susceptibility to allergen.

Smoking Cessation during the Second Half of Pregnancy Prevents Low Birth Weight among Australian Born Babies in Regional New South Wales

Smoking during pregnancy is a modifiable risk behavior of adverse health outcomes including low birth weight (LBW), and LBW is a key marker of newborns immediate and future health. This study aimed to examine the association between smoking cessation during the second half of pregnancy and LBW among babies born in Southern New South Wales Local Health District (SNSWLHD). Routinely collected perinatal data on singleton live births for the period 2011–2019 in five public hospitals of SNSWLHD were utilized. Multivariate logistic regression models were fitted to examine the association between smoking cessation during the second half of pregnancy and LBW. Analyses showed that mothers who ceased smoking during the second half of pregnancy were 44% less likely to have LBW babies (adjusted odds ratio (aOR) = 0.56; 95% confidence interval (CI): 0.34, 0.94) compared to those who continued smoking throughout pregnancy. Mothers who reported an average daily dose of 1–10 or >10 cigarettes during the second half of pregnancy were significantly more likely to have babies with LBW than those who ceased smoking during the second half of pregnancy. Early identification of smoking behavior and promotion of smoking-cessation intervention for risk populations including pregnant women within the older age bracket (35–49 years) is imperative to reduce LBW.

Patterns of respiratory health services utilization from birth to 5 years of children who experienced adverse birth outcomes

Introduction

Adverse birth outcomes have important consequences for future lung health. We evaluated patterns of respiratory health services utilization in early childhood among children born preterm (PTB), small and large for gestational age at term (SGA and LGA, respectively), and appropriate-for-gestational age at term.

Materials and methods

We conducted a population-based retrospective cohort study using administrative health data of all singleton live births in Alberta, Canada between 2005–2010. Data on hospitalizations and emergency department (ED) visits from birth to 5 years were collected for asthma, bronchitis, bronchiolitis, croup, influenza, pneumonia, and other acute upper and lower respiratory tract infections (other URTI and other LRTI, respectively). Adjusted rate ratios were estimated for respiratory ED visits and hospitalizations for adverse birth outcomes using the appropriate-for-gestational age at term group as reference. Age-specific trajectories of total respiratory health services utilization rates for each group were estimated in Poisson models.

Results

A total of 293,764 episodes of respiratory care from 206,994 children were analyzed. Very PTB children had the highest rates of health services use for all respiratory conditions, particularly for asthma, pneumonia, and bronchiolitis hospitalizations. Moderate/late PTB children also had elevated ED visits and hospitalizations for all respiratory conditions. Children born SGA showed high rates of ED visits for other LRTI, and of hospitalizations for bronchitis, bronchiolitis, and other URTI. Children born LGA had high rates of croup and other URTI ED visits, and of bronchiolitis and bronchiolitis hospitalizations. Age-specific trajectories showed a decreasing trend in the rates of total respiratory health service utilization from birth to five years of age for all groups studied. Children born PTB and LGA at term significantly required more respiratory health services over time compared to the reference group.

Conclusion

Patterns of paediatric respiratory health services utilization vary according to gestational age and fetal growth.

Perinatal granulopoiesis and risk of pediatric asthma

There are perinatal characteristics, such as gestational age, reproducibly associated with the risk for pediatric asthma. Identification of biologic processes influenced by these characteristics could facilitate risk stratification or new therapeutic targets. We hypothesized that transcriptional changes associated with multiple epidemiologic risk factors would be mediators of pediatric asthma risk. Using publicly available transcriptomic data from cord blood mononuclear cells, transcription of genes involved in myeloid differentiation was observed to be inversely associated with a pediatric asthma risk stratification based on multiple perinatal risk factors. This gene signature was validated in an independent prospective cohort and was specifically associated with genes localizing to neutrophil-specific granules. Further validation demonstrated that umbilical cord blood serum concentration of PGLYRP-1, a specific granule protein, was inversely associated with mid-childhood current asthma and early-teen FEV1/FVCx100. Thus, neutrophil-specific granule abundance at birth predicts risk for pediatric asthma and pulmonary function in adolescence.

Factors Associated with the Development of Childhood Asthma in Japan: A Nationwide Longitudinal Study

INTRODUCTION

Many environmental factors are related to the development of asthma. However, the key factors of childhood asthma onset have not been sufficiently elucidated. Further, low-weight births have increased in Japan. The aim of this study was to examine the risk factors for the incidence of childhood asthma and to evaluate whether these risk factors differ according to birth weight in Japan.

METHODS

We used the National Longitudinal Survey from 2001 to 2010. Multiple logistic regression analyses were conducted to determine the effects of gender, birth weight, single vs. multiple births, birth order, nutrition, keeping pets in the home, place of residence, annual household income, and parent ages, smoking behaviors, and educational backgrounds on asthma-related hospital visits.

RESULTS

Overall, 45,060 children were analyzed. The rate of cumulative hospital visits until age 10 was 18.9%. Birth weight < 2500 g (adjusted odds ratio [AOR] = 1.14, 95% confidence interval [CI] 1.03-1.26), being a boy (AOR = 1.27, 95% CI 1.21-1.33), having older siblings (AOR = 1.07, 95% CI 1.02-1.14), parental smoking behavior, mother`s age, and low household income (AOR = 1.17, 95% CI 1.10-1.24) were associated with asthma-related hospital visits.

DISCUSSION

Parental smoking behavior is a key risk factor for the development of asthma. Among low birth weight infants, being a boy, having older siblings, and father`s smoking behavior were predictive factors for the development of asthma. However, low birth weight was not associated with the development of asthma after 6 years of age.

Early life exposures and risk of adult respiratory disease during 50 years of follow-up

Adult health is influenced by factors during fetal life affecting organ development and birth weight. We aimed to study such factors in relation to adult respiratory disease (ARD) risk. The Helsingborg Birth Cohort, Sweden, contributed baseline data collected by medical staff through clinical examination and questionnaires on maternal and birth characteristics 1964-1967. Register linkages were performed with completions of data on ARD by ICD 8-10 classifications (1969-2016), and/or ARD-related drug usage (2005-2016) enabling a 50-year follow-up time. Cox proportional hazard regression analyses were made to adjust for potential confounders, adjusted hazard ratio (aHR). A total of 3675 mothers and their offspring were included. Female offspring showed higher frequency of ARD than males, aHR 1.5 (95% CI 1.3-1.8). Maternal use of sedatives during second trimester, aHR 2.2 (95% CI 1.4-3.4), and maternal smoking during most of pregnancy, aHR 1.2 (95% CI 1.0-1.4), were associated with offspring ARD. Stratified by sex, large-for-gestational-age, aHR 1.4 (95% CI 1.0-1.9), was significantly associated with ARD in female offspring along with maternal sedative use during second trimester and maternal smoking during most of pregnancy. Maternal sedative use during second trimester or all trimesters were the only significant risk factors for male offspring. In conclusion, maternal sedative use in second trimester was independently associated with subsequent respiratory disease in adult offspring irrespective of sex.

Causal Association Between Birth Weight and Adult Diseases: Evidence From a Mendelian Randomization Analysis

Purpose: Birth weight has a profound long-term impact on individual’s predisposition to various diseases at adulthood—a hypothesis commonly referred to as the fetal origins of adult diseases. However, it is not fully clear to what extent the fetal origins of adult diseases hypothesis holds and it is also not completely known what types of adult diseases are causally affected by birth weight.

Materials and methods: Mendelian randomization using multiple genetic instruments associated with birth weight was performed to explore the causal relationship between birth weight and adult diseases. The causal relationship between birth weight and 21 adult diseases as well as 38 other complex traits was examined based on data collected from 37 large-scale genome-wide association studies with up to 340,000 individuals of European ancestry. Causal effects of birth weight were estimated using inverse-variance weighted methods. The identified causal relationships between birth weight and adult diseases were further validated through extensive sensitivity analyses, bias calculation, and simulations.

Results: Among the 21 adult diseases, three were identified to be inversely causally affected by birth weight after the Bonferroni correction. The measurement unit of birth weight was defined as its standard deviation (i.e., 488 g), and one unit lower birth weight was causally related to an increased risk of coronary artery disease (CAD), myocardial infarction (MI), type 2 diabetes (T2D), and BMI-adjusted T2D, with the estimated odds ratios of 1.34 [95% confidence interval (CI) 1.17–1.53], 1.30 (95% CI 1.13–1.51), 1.41 (95% CI 1.15–1.73), and 1.54 (95% CI 1.25–1.89), respectively. All these identified causal associations were robust across various sensitivity analyses that guard against various confounding due to pleiotropy or maternal effects as well as reverse causation. In addition, analysis on 38 additional complex traits did not identify candidate traits that may mediate the causal association between birth weight and CAD/MI/T2D.

Conclusions: The results suggest that lower birth weight is causally associated with an increased risk of CAD, MI, and T2D in later life, supporting the fetal origins of adult diseases hypothesis.

Maternal vitamin D deficiency during pregnancy and low birth weight: a systematic review and meta-analysis

OBJECTIVE

The object of the present study was to estimate the relationship between maternal vitamin D deficiency during pregnancy and low birth weight by systematically review prevalence studies.

METHODS

We collected data from relevant studies published up to April 2019 using predefined inclusion/exclusion criteria. And all the studies were searched in PubMed, Embase, Cochrane Library, and Web of Science.

RESULTS

A total of 16 studies met the criteria and were included in the meta-analysis. When compared with normal serum levels of vitamin D, the maternal vitamin D deficiency had an increased risk of low birth weight (OR = 2.39; 95%CI 1.25-4.57; p = .008), and same results were found in the comparison of the mean (the total mean birth weight decreased by 0.08 kg; 95%CI -0.10 to -0.06; p < .001).

CONCLUSION

The evidence from this meta-analysis indicates a consistent association between vitamin D deficiency during pregnancy and an increased risk of low birth weight, and preventing maternal vitamin D deficiency may be an important public health strategy to help decrease the risk of low birth weight.

Acculturation or unequal assimilation? Smoking during pregnancy and duration of residence among migrants in Sweden

A growing corpus of evidence reveals that smoking patterns of migrant women tend to converge with that of the host population over time ('acculturation paradox'). In this paper we aim to adopt a health equity perspective by studying the extent to which this pattern reflects a convergence with the group of natives who are more socioeconomically disadvantaged. Using population-based registers, we study 1,194,296 women who gave birth in Sweden between 1991 and 2012. Using logistic regression, we estimated odds ratios to assess the effect of duration of residence on the association between smoking during pregnancy and women's origin (classified according to inequality-adjusted Human Development Index (iHDI) of the country of birth). Sibling information and multilevel models were used to assess the extent to which our results might be affected by the cross-sectional nature of the data. Smoking during pregnancy increases with duration of residence among migrants from all levels of iHDI to such an extent that they tend to converge or increase in relation to the levels of the Swedish population with low education and low income, leaving behind the native population with high education and income. The results are robust to possible selection bias related to the cross-sectional nature of the data. Our findings indicate the need of a health equity perspective and suggest the use of 'unequal assimilation' rather than 'acculturation paradox' as a more suitable framework to interpret these findings.

Birth weight is not causally associated with adult asthma: results from instrumental variable analyses

The association between lower birth weight and childhood asthma is well established. However, it remains unclear whether the influence of lower birth weight on asthma can persist into adulthood. We conducted a Mendelian randomization analysis to assess the causal relationship of birth weight (~140,000 individuals) on the risk of adult asthma (~62,000 individuals). We estimated the causal effect of birth weight to be 1.00 (95% CI 0.98~1.03, p = 0.737) using the genetic risk score method. We did not observe nonlinear relationship or gender difference for the estimated causal effect. With the inverse-variance weighted method, the causal effect of birth weight on adult asthma was estimated to be 1.02 (95% CI 0.84~1.24, p = 0.813). Additionally, the iMAP method provides no additional genome-wide evidence supporting the causal effects of birth weight on adult asthma. Our results were robust against various sensitivity analyses, and MR-PRESSO and MR-Egger regression showed that no instrument outliers and no horizontal pleiotropy were likely to bias the results. Overall, our study provides no evidence for the fetal origins of diseases hypothesis for adult asthma, implying that the impact of birth weight on asthma in years of children and adolescents does not persist into adult and previous findings may be biased by confounders.

Clinical and Pathologic Factors Predicting Future Asthma in Wheezing Children. A Longitudinal Study

Wheeze is a common symptom in infants, but not all wheezers develop asthma. Indeed, up to 50% of wheezing children outgrow their symptoms by school age. How to predict if early wheeze will become asthma is still a matter of vivid debate. In this work, we sought to assess the clinical and pathological factors that might predict the future development of asthma in children. Eighty children (mean age 3.8 ± 1 yr) who underwent a clinically indicated bronchoscopy were followed prospectively for a median of 5 years. At baseline, clinical characteristics with a particular focus on wheezing and its presentation (episodic or multitrigger) were collected, and structural and inflammatory changes were quantified in bronchial biopsies. Follow-up data were available for 74 of the 80 children. Children who presented with multitrigger wheeze were more likely to have asthma at follow-up than those with episodic wheeze (P = 0.04) or without wheeze (P < 0.0001). Children with asthma also had lower birth weights (P = 0.02), a lower prevalence of breastfeeding (P = 0.02), and a trend for increased IgE (P = 0.07) at baseline than those with no asthma. Basement membrane thickness and airway eosinophils at baseline were increased in children who developed asthma at follow-up (P = 0.001 and P = 0.026, respectively). Multivariate analysis showed that among all clinical and pathological factors, multitrigger wheezing, basement membrane thickening, and reduced birth weight were predictive of future asthma development. We conclude that multitrigger wheeze and reduced birth weight are clinical predictors of asthma development. Basement membrane thickening in early childhood is closely associated with asthma development, highlighting the importance of airway remodeling in early life as a risk factor for future asthma.

Effects of intrauterine growth restriction and postnatal nutrition on pediatric asthma in Bangladesh

Numerous studies have investigated the risk of developing asthma due to early-life experiences and environmental exposures. However, the influence of intrauterine growth restriction and postnatal undernutrition on childhood wheezing/asthma remains unclear. Thus, we examined the effects of both small for gestational age (SGA) and postnatal stunted growth on ever asthma among children in the rural areas in Bangladesh.Multiple follow-up studies were conducted in a cohort of randomized clinical trial of nutrition interventions during pregnancy (the MINIMat trial). Overall, 1208 and 1697 children were followed-up for asthma at 4.5 and 10 years, respectively. Anthropometric measurements were obtained at various intervals from birth to 10 years of age. Ever asthma was identified using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.Results showed that SGA was significantly associated with increased risk of ever asthma at 4.5 and 10 years after adjusting for sex, body mass index, socioeconomic status, family history of asthma, gestational age at birth, mother's parity, mother's age at birth and intervention trial arm [odds ratio (OR)=1.97 (95% confidence interval (CI): 1.34-2.90) and 1.86 (95% CI: 1.18-2.72)]. For the postnatal effect of undernutrition, stunting at 1 and 2 years was significantly associated with ever asthma at 4.5 and 10 years [1 year: OR=1.77 (95% CI: 1.22-2.57) and OR=1.72 (95% CI: 1.16-2.56), 2 years: OR=1.49 (95% CI: 1.06-2.10) and OR=1.41 (95% CI: 1.02-1.96)].In conclusion, SGA and undernutrition during infancy has an influence on childhood asthma among children in Bangladesh, indicating the need for nutritional interventions early in life.

Inhibition of thymocyte autophagy-associated CD4+T thymopoiesis is involved in asthma susceptibility in mice exposed to caffeine prenatally

Our previous studies demonstrated that prenatal caffeine exposure (PCE) caused thymopoiesis inhibition, immune disorders, and airway remodeling in offspring, which raises the question of whether PCE is a risk factor for postnatal asthma. Meanwhile, the mechanism of PCE-induced thymopoiesis inhibition is not clear yet. Considering caffeine's pro-autophagy effects (lacking evidence in thymus) and the important role of autophagy in maintaining thymopoiesis, this study aimed to investigate whether PCE contributes to asthma susceptibility, and further explore the molecular mechanisms of thymopoiesis inhibition from the perspective of pro-autophagy effects of caffeine both in vivo and in vitro. The PCE mouse model was established by 96 mg/kg/day caffeine administration from gestational day (GD) 9-GD 18, and an asthma model was established on the offspring by ovalbumin sensitization and challenge. The results confirmed our hypothesis that PCE could suppress pulmonary CD4⁺T development and aggravate allergen-induced asthma symptoms in the offspring. In fetuses, PCE significantly suppressed A2AR-PKA signaling, upregulated Beclin1-LC3II autophagy, promoted Bcl10 degradation, reduced A20 expression, and inhibited CD4⁺T thymopoiesis. Similar results were also observed in 4 µM caffeine-treated thymocytes in vitro. Moreover, inhibiting A2AR by antagonist (SCH 58261) performed the same downstream biological effects as caffeine treatment, and autophagy inhibitor (BafilomycinA1) clearly abolished the caffeine-induced Bcl10 degradation and A20 suppression. In conclusion, our findings, for the first time, showed that PCE could attenuate CD4⁺T thymopoiesis and suppress pulmonary CD4⁺T development by directly enhancing autophagy in thymocytes, and provided a firm experimental evidence that PCE is a risk factor for postnatal asthma.

A dynamic, modifiable model for estimating cost-effectiveness of smoking cessation interventions in pregnancy: application to an RCT of self-help delivered by text message

BACKGROUND AND AIMS

Previous evaluations of smoking cessation interventions in pregnancy have several limitations. Our solution to these limitations is the Economics of Smoking in Pregnancy (ESIP) model, which estimates the life-time cost-effectiveness of smoking cessation interventions in pregnancy from a National Health Service (NHS) and personal social services perspective. We aim to (1) describe how ESIP has been constructed and (2) illustrate its use with trial data.

METHODS

ESIP links mothers' and offspring pregnancy outcomes to estimate the burdens of smoking-related disease they experience with different rates of smoking in pregnancy, both in pregnancy and throughout their life-times. Smoking rates are inputted by model users. ESIP then estimates the costs of treating disease burdens and also mothers' and offspring life-years and quality-adjusted life years (QALYs). By comparing costs incurred and healthy life following different smoking rates, ESIP estimates incremental cost-effectiveness and benefit-cost ratios for mothers or offspring or both combined. We illustrate ESIP use using data from a pragmatic randomized controlled trial that tested a smoking cessation intervention in pregnancy.

RESULTS

Throughout women's and offspring life-times, the intervention proved cheaper than usual care, having a negative incremental cost of £38.37 (interquartile range = £21.46-56.96) and it improved health, demonstrating a 0.04 increase in incremental QALYs for mothers and offspring, implying that it is 'dominant' over usual care. Benefit-cost ratios suggested that every £1 spent would generate a median of £14 (interquartile range = £8-20) in health-care savings.

CONCLUSIONS

Economics of Smoking in Pregnancy is the first economic model to link mothers' and infants' costs and benefits while reporting cost-effectiveness in readily-comparable units. Using ESIP with data from a trial which reported only short-term economic analysis showed that the intervention was very likely to be cost-effective in the longer term and to generate health-care savings.

Birth weight for gestational age and the risk of asthma in childhood and adolescence: a retrospective cohort study

OBJECTIVE

To examine the association between birth weight for gestational age and asthma in childhood and adolescence while controlling for potential confounders and considering smoking as an effect modifier.

METHODS

A retrospective cohort of all singleton term births in Nova Scotia, Canada, between 1989 and 1993 was identified in the provincial perinatal database and followed through 2014 by linking with administrative health data. The outcome, asthma, was defined as having one hospitalisation or two physician visits with an International Classification of Diseases code for asthma in a 2-year period. Birth weight was categorised as small (SGA), large (LGA) or appropriate (AGA) for gestational age. Multivariable-adjusted Cox proportional hazards models were used to examine the association between the birth weight for gestational age and asthma and to test for effect modification by maternal smoking in pregnancy.

RESULTS

Of the 40 724 cohort children, 10.5% and 11.7% were born SGA and LGA, respectively, and the risk of developing asthma to age 18 years was 30.2%. The adjusted HRs for SGA and LGA (relative to AGA) and asthma were 1.07 (95% CI 1.02 to 1.14) and 0.96 (95% CI 0.91 to 1.02), respectively. Relative to AGA children born to non-smoking mothers, SGA children were not at increased risk of asthma (HR 1.02), whereas both AGA and SGA children born to smoking mothers were at significantly increased risk (HR 1.14 and 1.29, respectively).

CONCLUSIONS

Our findings suggest that SGA in term infants is not associated with asthma in childhood in the absence of smoking in pregnancy.

Factors associated with asthma expression in adolescents

Objective:

To evaluate risk factors associated with asthma symptoms in adolescents in the 13- to 14-year age bracket.

Methods:

This was a cross-sectional study involving adolescents enrolled in randomly selected public schools in the city of Belo Horizonte, Brazil, and conducted with the use of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and its supplementary module for risk factor assessment. The ISAAC questionnaire was completed by the students themselves, whereas the supplementary questionnaire was completed by their parents or legal guardians. Variables showing p ≤ 0.25 in the univariate analysis were included in the multivariate analysis. Stepwise regression with backward elimination was used for variable selection.

Results:

We evaluated 375 adolescents, 124 (33.1%) of whom had asthma symptoms. The final multivariate analysis model revealed that asthma symptoms were associated with birth weight < 2,500 g (p < 0.001), day care center or nursery attendance (p < 0.002), maternal history of asthma (p < 0.001), contact with animals during the first year of life (p < 0.027), current contact with animals outside the home (dogs, cats, or farm animals; p < 0.005), and more than 20 cigarettes per day smoked by parents or other household members (p < 0.02).

Conclusions:

Exposure to animals in and outside the home is associated with asthma symptoms, as is environmental tobacco smoke exposure. Families, health professionals, and administrators of health care facilities should take that into account in order to prevent asthma and reduce asthma morbidity.

Pathophysiological Mechanisms of Asthma

The recent Lancet commission has highlighted that "asthma" should be used to describe a clinical syndrome of wheeze, breathlessness, chest tightness, and sometimes cough. The next step is to deconstruct the airway into components of fixed and variable airflow obstruction, inflammation, infection and altered cough reflex, setting the airway disease in the context of extra-pulmonary co-morbidities and social and environmental factors. The emphasis is always on delineating treatable traits, including variable airflow obstruction caused by airway smooth muscle constriction (treated with short- and long-acting β-2 agonists), eosinophilic airway inflammation (treated with inhaled corticosteroids) and chronic bacterial infection (treated with antibiotics with benefit if it is driving the disease). It is also important not to over-treat the untreatable, such as fixed airflow obstruction. These can all be determined using simple, non-invasive tests such as spirometry before and after acute administration of a bronchodilator (reversible airflow obstruction); peripheral blood eosinophil count, induced sputum, exhaled nitric oxide (airway eosinophilia); and sputum or cough swab culture (bacterial infection). Additionally, the pathophysiology of risk domains must be considered: these are risk of an asthma attack, risk of poor airway growth, and in pre-school children, risk of progression to eosinophilic school age asthma. Phenotyping the airway will allow more precise diagnosis and targeted treatment, but it is important to move to endotypes, especially in the era of increasing numbers of biologicals. Advances in -omics technology allow delineation of pathways, which will be particularly important in TH2 low eosinophilic asthma, and also pauci-inflammatory disease. It is very important to appreciate the difficulties of cluster analysis; a patient may have eosinophilic airway disease because of a steroid resistant endotype, because of non-adherence to basic treatment, and a surge in environmental allergen burden. Sophisticated -omics approaches will be reviewed in this manuscript, but currently they are not being used in clinical practice. However, even while they are being evaluated, management of the asthmas can and should be improved by considering the pathophysiologies of the different airway diseases lumped under that umbrella term, using simple, non-invasive tests which are readily available, and treating accordingly.

Liraglutide Enhances the Activity of the ACE-2/Ang(1-7)/Mas Receptor Pathway in Lungs of Male Pups from Food-Restricted Mothers and Prevents the Reduction of SP-A

In utero growth restriction and being born small for gestational age are risk factors for respiratory morbidity. IUGR (in utero growth retardation) is associated to overall reduction in lung weight, surfactant content and activity, impaired maturation of the alveolar type II cells, and decreased alveolar formation. The renin-angiotensin system (RAS) may be a key target underlying pathophysiological lung alterations. GLP-1 and agonists of its receptor modulate the expression levels of different components of RAS and also are very important for lung maturation and the production of surfactant proteins. The aim of this study was to elucidate the effects of IUGR induced by perinatal food restriction of the mother in the lung function of pups at early stages of life (PD21) and to determine if liraglutide had any effect during gestational period. Sprague-Dawley pregnant rats were randomly assigned to 50% food restriction (MPFR) or ad libitum control (CT) groups at day of pregnancy 12 (GD12). From GD14 to parturition, pregnant MPFR and CT rats were treated with liraglutide or vehicle. At postnatal day 21 and before weaning, 20 CT and 20 FR male pups were sacrificed and lungs were analyzed by RT-PCR. Liraglutide restored surfactant protein A (SP-A) mRNA expression in pup lungs from food-restricted mothers. Surfactant protein B (SP-B) mRNA expression is not affected by neither IUGR nor liraglutide treatment. Moreover, liraglutide modulated different elements of RAS, increasing angiotensin-converting enzyme 2 (ACE2) and MasR mRNA expression only in pups from food-restricted mothers (MPFR), despite food restriction had not any direct effect at this early stage. Liraglutide also increased endothelial nitric oxide synthase (eNOS) expression in MPFR lungs, reflecting the activation of MasR by angiotensin 1-7. In conclusion, liraglutide prevented the alteration in lung function induced by IUGR and promoted the positive effects of ACE2-Ang(1-7)-MasR in restoring lung function.

Milk Other Than Breast Milk and the Development of Asthma in Children 3 Years of Age. A Birth Cohort Study (2006⁻2011)

Prevalence of asthma in Australian children is amongst the highest in the world. Although breastfeeding positively influences infant immunity, early introduction of Milk Other than Breast Milk (MOTBM) may also play an important role in the development of Asthma. The aim of this study was to investigate the association between the introduction of MOTBM in the first six months after birth and the development of reported persistent asthma in 3-year olds. A sample of 1121 children was extracted from the Environments for Healthy Living longitudinal birth cohort study. Introduction of MOTBM during the first six months after birth increased almost two-fold the risk of development of persistent asthma after adjusting for other covariates (Adjusted Relative Risk (ARR): 1.71, 95% CI: 1.03⁻2.83, p = 0.038). This study indicates that the introduction of MOTBM in the first six months of life is a risk factor for asthma incidence among 3-year old children. This result is important in explaining the benefits of breastfeeding as part of public health interventions to encourage mothers to increase breastfeeding initiation and duration, and avoid the introduction of MOTBM in the first six months after childbirth.

Low birth weight and its associated factors

OBJECTIVE

To calculate the frequency and evaluate the factors associated with low birth weight.

METHODS

A retrospective study, with data from pregnant women who participated in the Programa de Atenção às Gestantes do Programa Einstein na Comunidade de Paraisópolis, between 2011 and 2014, and who returned for the postpartum evaluation of their newborns. Variables related to the pregnant woman, pregnancy, and newborn were evaluated. The outcome variable was low birth weight, defined as <2.5kg. The associations between the independent variables and low birth weight were assessed by χ2 and Mann-Whitney tests. Logistic regression models analyzed the combined effects of the independent variables on low birth weight.

RESULTS

Data of 794 pregnant women and their newborns (52.1% males) were analyzed. The age of pregnant women varied from 13 to 44 years (median of 24 years), and the majority reported being married or living in cohabitation (74.7%), and having between 9 to 11 years of schooling (53.4%). The proportion of low birth weight was 7.6% (newborn mean weight of 3.2kg) and, in multivariate analysis, presence of twinning, age group of the pregnant women (showing protection for low birth weight between ages ≥18 years and <35 years), and cesarean section were associated with low birth weight.

CONCLUSION

The proportion of low birth weight was 7.6% and twining, age of the pregnant woman, and cesarean delivery were associated with the occurrence of low birth weight.

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.

The impact of fetal umbilical artery Doppler pulsatility index on childhood respiratory function and atopy: a prospective case-control study

Objective: To determine if an elevated fetal umbilical artery Doppler pulsatility index is associated with abnormal respiratory function and atopy in children aged 12 years.Methods: This prospective case-control study compared children that had an elevated fetal umbilical artery Doppler pulsatility index (>90th centile) to those with a normal pulsatility index (<90th centile). All subjects were delivered at full-term and with appropriate growth for gestational age. Outcome measures included; (i) presence of asthma and/or atopy; (ii) spirometry measurements and (iii) serum C-reactive protein and leptin. Multiple regression was used to account for parental smoking, childhood age, gender and socioeconomic status.Results: 174 children with an average age of 12.1 (±0.6 SD), 48% of who were male were included in the analysis. Of the 174, 99 (57%) were in the normal umbilical artery Doppler pulsatility index group and 75 (43%) elevated umbilical artery Doppler pulsatility index groups. The overall proportion of subjects with asthma was 28% (48/174) and atopy 56% (98/174). No association was found between elevated fetal umbilical artery Doppler pulsatility index and asthma (p = .47) or atopy (p = .75) at age 12 years. Similarly there was no association between FEV1(%) (p = .96), forced vital capacity (FVC)(%) (p = .98), elevated serum C-reactive protein (p = .69) or leptin (p = .20) and an elevated fetal umbilical artery Doppler pulsatility index.Conclusions: An elevated umbilical artery Doppler at 28-weeks gestation in the absence of prematurity or fetal growth restriction is not associated with altered respiratory function or the presence of atopy in children aged 12 years. These findings support the theory that such disease has a multifactorial pathophysiology.

Prenatal Exposure to Ambient Pesticides and Preterm Birth and Term Low Birthweight in Agricultural Regions of California

Findings from studies of prenatal exposure to pesticides and adverse birth outcomes have been equivocal so far. We examined prenatal exposure to agricultural pesticides in relation to preterm birth and term low birthweight, respectively, in children born between 1998 and 2010, randomly selected from California birth records. We estimated residential exposure to agriculturally applied pesticides within 2 km of residential addresses at birth by pregnancy trimester for 17 individual pesticides and three chemical classes (organophosphates, pyrethroids, and carbamates). Among maternal addresses located within 2 km of any agricultural pesticide application, we identified 24,693 preterm and 220,297 term births, and 4412 term low birthweight and 194,732 term normal birthweight infants. First or second trimester exposure to individual pesticides (e.g., glyphosates, paraquat, imidacloprid) or exposure to 2 or more pesticides in the three chemical classes were associated with a small increase (3⁻7%) in risk for preterm birth; associations were stronger for female offspring. We did not find associations between term low birthweight and exposure to pesticides other than myclobutanil (OR: 1.11; 95% CI: 1.04⁻1.20) and possibly the pyrethroids class. Our improved exposure assessment revealed that first and second trimester exposure to pesticides is associated with preterm delivery but is rarely linked with term low birthweight.

Pregnancy and perinatal conditions and atopic disease prevalence in childhood and adulthood

BACKGROUND

Previous studies showed controversial results for the influence of pregnancy-related and perinatal factors on subsequent respiratory and atopic diseases in children. The aim of this study was to assess the association between perinatal variables and the prevalence of asthma, bronchial hyperreactivity (BHR), flexural eczema (FE), allergic rhinitis, and sensitization in childhood and early adulthood.

METHODS

The studied population was first examined in Munich and Dresden in 1995/1996 at age 9-11 years. Participants were followed until age 19-24 years using questionnaires and clinical examinations. Associations between perinatal data and subsequent atopic diseases were examined using logistic regression analyses adjusting for potential confounders.

RESULTS

Cesarean section was statistically significantly associated with BHR in early adulthood (odds ratio 4.8 [95% confidence interval 1.5-15.2]), while assisted birth was associated with presence of asthma symptoms in childhood (2.2 [1.2-3.9]), FE symptoms (2.2 [1.2-4.3]) and doctor's diagnosis of atopic dermatitis (1.9 [1.0-3.4]) in childhood, and sensitization in early adulthood (2.2 [1.1-4.3]). Lower birth length (1.9 [1.1-3.2]), lower birthweight (0.5 [0.3-0.9]), and higher birthweight (0.6 [0.4-1.0]) were predictive of sensitization in early adulthood compared to average birth length and birthweight, respectively. None of the other perinatal factors showed statistically significant associations with the outcomes.

CONCLUSIONS

Our results indicate that children who are born by cesarean section and especially by assisted birth, might be at greater risk for developing asthma, FE, and sensitization and should hence be monitored. Prenatal maternal stress might partly explain these associations, which should be further investigated.

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.

Late-gestation maternal dietary methyl donor and cofactor supplementation in sheep partially reverses protection against allergic sensitization by IUGR

Perinatal exposures are associated with altered risks of childhood allergy. Human studies and our previous work suggest that restricted growth in utero (IUGR) is protective against allergic disease. The mechanisms are not clearly defined, but reduced fetal abundance and altered metabolism of methyl donors are hypothesized as possible underlying mechanisms. Therefore, we examined whether late-gestation maternal dietary methyl donor and cofactor supplementation of the placentally restricted (PR) sheep pregnancy would reverse allergic protection in progeny. Allergic outcomes were compared between progeny from control pregnancies (CON; n = 49), from PR pregnancies without intervention (PR; n = 28), and from PR pregnancies where the dam was fed a methyl donor plus cofactor supplement from day 120 of pregnancy until delivery (PR + Methyl; n = 25). Both PR and PR + Methyl progeny were smaller than CON; supplementation did not alter birth size. PR was protective against cutaneous hypersensitivity responses to ovalbumin (OVA; P < 0.01 in singletons). Cutaneous hypersensitivity responses to OVA in PR + Methyl progeny were intermediate to and not different from the responses of CON and PR sheep. Cutaneous hypersensitivity responses to house dust mites did not differ between treatments. In singleton progeny, upper dermal mast cell density was greater in PR + Methyl than in PR or CON (each P < 0.05). The differences in the cutaneous allergic response were not explained by treatment effects on circulating immune cells or antibodies. Our results suggest that mechanisms underlying in utero programming of allergic susceptibility by IUGR and methyl donor availability may differ and imply that late-gestation methyl donor supplementation may increase allergy risk.

Breastfeeding and perinatal exposure, and the risk of asthma and allergies

PURPOSE OF REVIEW

Exposures during the perinatal period, a phase of rapid development, may have a profound and sustained effect on disease risk. In particular, perinatal exposures may influence the development and maturation of the infant immune system and the risk of allergic disease. We aimed to summarize the current literature on perinatal exposures and the risk of asthma and allergic disease

RECENT FINDINGS

Increased risk of offspring wheeze or asthma was found for: maternal obesity and hypertension during pregnancy; febrile illness, gynaecological, and viral respiratory infections in pregnancy; exposure to bisphenol A and phthalates in pregnancy and childhood; exposure to smoking in utero; low birth weight; caesarean section and neonatal hyperbilirubinaemia. Reduced risk of offspring atopic eczema was found for hookworm infection in pregnancy and reduced risk of offspring wheeze was associated with increased pregnancy dietary intake of vitamin E and zinc. Higher levels of selenium in pregnancy were associated with less risk of asthma in genetically susceptible offspring. Early life pet ownership was associated with a decrease in atopic asthma but an increase in nonatopic asthma risk.

SUMMARY

A diverse range of exposures were associated with allergic disease risk, highlighting the susceptibility of children during the perinatal period. Clinicians should reinforce public health messages concerning maternal obesity, smoking, and breastfeeding. The infant gut microbiome is emerging as an important hypothesis, which may mediate the relationship between many perinatal exposures and allergic disease.