Maternal complications in pregnancy and wheezing in early childhood: a pooled analysis of 14 birth cohorts

Maternal gestational diabetes mellitus and risk of allergic diseases in offspring

BACKGROUND

Gestational diabetes mellitus has been linked to inflammation, immune dysregulation in offspring, and changes in the microbiota. It may have long-term implications for the health of children. The aim of this study was to determine if gestational diabetes mellitus increases the risk of allergic diseases in offspring.

METHODS

The data source was the National Health Insurance Research Database (NHIRD) of Taiwan. The pairing of mothers and children was established by connecting the NHIRD with the Taiwan Maternal and Child Health Database. First-time pregnant mothers between 2004 and 2019 were enrolled. The GDM group consisted of 22,741 cases. The control group was selected from individuals without GDM matched by maternal age, neonatal gender, and neonatal birthdate at a ratio of 1-4. The primary endpoint was the incidence of childhood allergic diseases, such as asthma, allergic rhinitis, atopic dermatitis, and urticaria. The secondary endpoint was the risk associated with the development of allergic diseases in offspring, considering the presence or absence of insulin therapy.

RESULTS

The development of allergic rhinitis, atopic dermatitis, and urticaria were found to be significantly associated with GDM. However, no significant association was observed between GDM and asthma. GDM control without insulin was associated with an increased risk of developing allergic rhinitis, urticaria, and atopic dermatitis. However, in the group receiving insulin treatment, there was no significant elevation in the risk of any allergic diseases.

CONCLUSION

GDM may elevate the risk of certain atopic diseases in offspring, such as allergic rhinitis, atopic dermatitis, and urticaria.

Asthma, classical conditioning, and the autonomic nervous system - a hypothesis for why children wheeze

Paediatric asthma is an increasing global healthcare problem for which current treatments are not always effective. This review explores how abnormal triggering of the autonomic diving reflex might be important in explaining research findings and the real-world experience of asthma. It hypothesises that the way in which stress during pregnancy is associated with childhood asthma could be through effects on the developing nervous system. This results in increased parasympathetic responsiveness and specifically, excessive triggering of the diving reflex in response to wetting and cooling of the face and nose as occurs with upper airway infections and allergic rhinitis. In aquatic mammals the reflex importantly includes the contraction of airway smooth muscle to minimise lung volume and prevent nitrogen narcosis from diving at depth. Misfiring of this reflex in humans could result in the pathological airway narrowing that occurs in asthma. The diving reflex, and possibly also smooth muscle, is a vestigial remnant of our aquatic past. The hypothesis further suggests that classically conditioned reflex responses to neutral cues and contexts that were present at the same time as the stimuli that initially caused symptoms, become of themselves ongoing triggers of recurrent wheeze. Symptoms occurring in this way, irrespective of the presence of allergens and ongoing airway sensitisation, explain why allergen avoidance is poorly effective in alleviating wheeze and why asthma is made worse by stress. Interventions to suppress the diving reflex and to prevent reflex conditioned wheezing could result in more effective asthma management.

Maternal prepregnancy body mass index, gestational weight gain, and allergic diseases in children: A systematic review and meta-analysis

Several studies have investigated a link between maternal preconception body mass index, gestational weight gain (GWG), and the risk of childhood allergic diseases, but the conclusions of these studies were inconsistent. This review aimed to evaluate the relationship based on existing studies. We eventually included 18 cohort studies. The findings indicated that both maternal preconception overweight or obesity increased the risk of childhood wheezing (overweight: risk ratio (RR) 1.09, 95% confidence interval (CI) 1.04-1.15; obesity: RR 1.24, 95% CI 1.12-1.38) and asthma (overweight: RR 1.18, 95% CI 1.05-1.32; obesity: RR 1.34, 95% CI 1.13-1.58), and the risk of childhood wheezing increased with continuous prepregnancy BMI changes (per 5 kg/m2 increase) (RR 1.10, 95% CI 1.05-1.15). Preconception underweight may elevate the risk of childhood eczema ever (RR 1.05, 95% CI 1.02-1.09) and current eczema (RR 1.20, 95% CI 1.05-1.37), and preconception overweight may reduce the risk of childhood eczema ever (RR 0.98, 95% CI 0.96-0.99). No statistically significant association between GWG and the risk of allergic diseases in children was found. Preconception weight management is encouraged for the prevention of allergic diseases in children.

Oat β-glucan supplementation pre- and during pregnancy alleviates fetal intestinal immunity development damaged by gestational diabetes in rats

Oat β-glucan (OG) has been shown to improve intestinal microecology in gestational diabetes mellitus (GDM), but the effect on fetal intestine health is unknown. Herein, we aimed to investigate the effects of OG supplementation during gestation in GDM dams on fetal intestinal immune development. OG was supplemented one week before mating until the end of the experiment. GDM rats were made with a high-fat diet (HFD) with a minimal streptozotocin (STZ) dose. The fetal intestines were sampled at gestation day (GD) 19.5, and the intestinal morphology, chemical barrier molecules, intraepithelial immune cell makers, and levels of inflammatory cytokines were investigated. The results showed that OG supplementation alleviated the decrease of the depth of fetal intestinal villi and crypts, the number of goblet cells (GCs), protein expression of mucin-1 (Muc1) and Muc2, the mRNA levels of Gpr41, Gpr43, and T cell markers, and increased the number of paneth cells (PCs), the mRNA levels of defensin-6 (defa6), and macrophage (Mø) marker and the expression of cytokines induced by GDM. In addition, OG supplementation alleviated the function of immune cell self-proliferation, chemotaxis and assembly capabilities, protein, fat, folic acid, and zinc absorption damaged by GDM. As indicated by these findings, OG supplementation before and during pregnancy improved the fetal intestinal chemical barriers, immune cells, cytokines, and the metabolism of nutrients to protect the fetal intestinal immunity.

Life Course of Asthma

Asthma is a heterogeneous chronic airway disease that can vary over a lifetime. Although broad categories of asthma by severity and type have been constructed, there remains a tremendous opportunity to discover an approach to managing asthma with additional factors in mind. Many in the field have suggested and are pursuing a novel paradigm shift in how asthma might be better managed, considering the life course of exposures, management priorities, and predicted trajectory of lung function growth. This approach will require a more holistic view of prenatal, postnatal, adolescence, hormonal and gender aspects, and the aging process. In addition, the environment, externally and internally, including in one's genetic code and epigenetic changes, are factors that affect how asthma progresses or becomes more stable in individuals. This chapter focuses on the various influences that may, to differing degrees, affect people with asthma, which can develop at any time in their lives. Shifting the paradigm of thought and strategies for care and advocating for public policies and health delivery that focus on this philosophy is paramount to advance asthma care for all.

Cohort Study of Maternal Gestational Weight Gain, Gestational Diabetes, and Childhood Asthma

Data on the association of maternal gestational weight gain (GWG) and gestational diabetes mellitus (GDM) with childhood asthma are limited and inconsistent. We aimed to investigate these associations in a U.S. pre-birth cohort. Analyses included 16,351 mother-child pairs enrolled in the Massachusetts General Hospital Maternal-Child Cohort (1998-2010). Data were obtained by linking electronic health records for prenatal visits/delivery to determine BMI, GWG, and GDM (National Diabetes Data Group criteria) and to determine asthma incidence and allergies (atopic dermatitis or allergic rhinitis) for children. The associations of prenatal exposures with asthma were evaluated using logistic regression adjusted for maternal characteristics. A total of 2306 children (14%) developed asthma by age 5 years. Overall, no association was found between GWG and asthma. GDM was positively associated with offspring asthma (OR 1.46, 95% CI 1.14-1.88). Associations between GDM and asthma were observed only among mothers with early pregnancy BMI between 20 and 24.9 kg/m² (OR 2.31, CI 1.46-3.65, p-interaction 0.02). We report novel findings on the impact of prenatal exposures on asthma, including increased risk among mothers with GDM, particularly those with a normal BMI. These findings support the strengthening of interventions targeted toward a healthier pregnancy, which may also be helpful for childhood asthma prevention.

The association between hypertensive disorders of pregnancy and childhood asthma

BACKGROUND

Asthma is a chronic long-term inflammatory disease of the airways and is a major global health challenge. The primary aim of this study was to investigate the association between hypertensive disorders of pregnancy (HDP) and the risk of asthma at or before the age of seven years using the UK Millennium Cohort Study (MCS).

METHODS

Overall, 18,552 families were recruited for wave one of the MCS when the child was 9 months old, and subsequently participated in waves two, three and four when they were three, five and seven years respectively. HDP were self-reported by mothers in wave one. The primary outcome was a parent-reported diagnosis of "ever asthma" at seven years, based on responses to a validated questionnaire.

RESULTS

Following adjustment for a range of potential confounding factors, HDP was found to be associated with asthma in the offspring (adjusted odds ratio (AOR 1.35; 95% CI: 1.15-1.59)). A larger effect estimate was observed amongst children exposed to HDP and born preterm (AOR 1.81; 95% CI: 1.25-2.61) or small for gestational age (SGA) (AOR = 1.58; (95% CI: 1.15-2.18)).

CONCLUSIONS

In conclusion, children exposed to HDP may be at increased odds of asthma diagnosis by age seven, particularly if they were born preterm or SGA.

IMPACT

There is a paucity of data investigating the relationship between hypertensive disorders of pregnancy and childhood asthma, with recent studies showing conflicting results. Our study investigated this relationship using a large cohort with ample information on a wide range of confounding factors. Our study showed that individuals exposed to HDP may be at increased odds of asthma diagnosis by age seven years, particularly if they were also born SGA or preterm.

Maternal obesity, gestational weight gain, and offspring asthma and atopy

BACKGROUND

Maternal obesity may affect offspring asthma and atopic disease risk by altering fetal immune system development. However, few studies evaluate gestational weight gain (GWG).

OBJECTIVE

To evaluate relationships between maternal body mass index (BMI), GWG, and persistent wheeze, eczema, allergy, and asthma risk in offspring through middle childhood.

METHODS

A total of 5939 children from Upstate KIDS, a population-based longitudinal cohort of children born in upstate New York (2008-2019) were included in the analysis. Persistent wheeze or asthma, eczema, and allergy were maternally reported at multiple study time points throughout early and middle childhood. Poisson regression models with robust SEs were used to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for offspring atopic outcomes by maternal prepregnancy BMI and GWG.

RESULTS

Prepregnancy BMI was associated with increased risk of persistent wheeze by 3 years of age even after adjustments for maternal atopy (class I obesity: aRR, 1.58; 95% CI, 1.13-2.20; class II or III obesity: aRR, 1.69; 95% CI, 1.22-2.35). Associations with reported asthma in middle childhood did not reach statistical significance. Furthermore, no associations were found between prepregnancy BMI and atopic outcomes in either early or middle childhood. GWG was not associated with higher risk of early childhood persistent wheeze or middle childhood asthma.

CONCLUSION

Maternal prepregnancy BMI was associated with increased risk of offspring wheeze, whereas excessive GWG was generally not associated with childhood asthma or atopy.

Colonization of the Newborn Respiratory Tract and Its Association with Respiratory Morbidity in the first six months of life: A Prospective Cohort Study

OBJECTIVE

We aimed to determine the association between newborn bacterial colonization and infant respiratory morbidity, in the first six months of life.

METHODS

This prospective study included healthy newborn infants. Nasopharyngeal swabs performed within 72hrs of delivery were analyzed via polymerase chain reaction. We assessed cumulative respiratory morbidity of infants at 6-months-old.

RESULTS

Four hundred and twenty-six mother-infant pairs were recruited. In 53.3% (n=225) of newborns, S. pneumoniae (46%) and S. aureus (7.3%) was isolated. None had H. influenzae nor M. catarrhalis. At 6-months-old, 50.7% had experienced respiratory symptoms, 25% had unscheduled doctor visits, and 10% were treated with nebulizers. Colonization with S.pneumoniae was associated with reduced risk of any respiratory symptom (aOR 0.39[95% CI 0.16,0.50]), unscheduled doctor visits (aOR 0.35 [95% CI 0.18,0.67]) and nebulizer treatment (aOR 0.23 [95% CI 0.07,0.72]) at 6 months. Pregnancy-induced hypertension was also associated with increased need for nebulizer treatment (aOR 9.11 [95% CI 1.43,58.1]).

CONCLUSION

Colonization of the newborn respiratory tract occurred in 53% of infants. Streptococcus pneumoniae was the most common organism, and this was associated with a reduced risk for respiratory morbidity at six months of life.

Pre-eclampsia and risk of early-childhood asthma: a register study with sibling comparison and an exploration of intermediate variables

BACKGROUND

We aimed to study whether pre-eclampsia is associated with childhood asthma, allergic and non-allergic asthma, accounting for family factors and intermediate variables.

METHODS

The study population comprised 779 711 children born in 2005-2012, identified from Swedish national health registers (n = 14 823/7410 exposed to mild/moderate and severe pre-eclampsia, respectively). We used Cox regression to estimate the associations of mild/moderate and severe pre-eclampsia with incident asthma, before and after age 2 years. Cox regressions were controlled for familial factors using sibling comparisons, then stratified on high and low risk for intermediate variables: caesarean section, prematurity and small for gestational age. We used logistic regression for allergic and non-allergic prevalent asthma at 6 years as a measure of more established asthma.

RESULTS

The incidence of asthma in children was 7.7% (n = 60 239). The associations varied from adjusted hazard ratio (adjHR) 1.11, 95% confidence interval (CI): 1.00, 1.24 for mild/moderate pre-eclampsia and asthma at >2 years age, to adjHR 1.78, 95% CI: 1.64, 1.95 for severe pre-eclampsia and asthma at <2 years age. Sibling comparisons attenuated most estimates except for the association between severe pre-eclampsia and asthma at <2 years age (adjHR 1.45, 95% CI: 1.10, 1.90), which also remained when stratifying for the risk of intermediates. Mild/moderate and severe pre-eclampsia were associated with prevalent non-allergic (but not allergic) asthma at 6 years, with adjusted odds ratio (adjOR) 1.17, 95% CI: 1.00, 1.36 and adjOR 1.51, 95% CI: 1.23, 1.84, respectively.

CONCLUSIONS

We found evidence that severe, but not mild/moderate, pre-eclampsia is associated with asthma regardless of familial factors and confounders.

Hypertensive disorders of pregnancy and risk of allergic conditions in children: Findings from the Japan Environment and Children's study (JECS)

Background

Hypertensive disorders of pregnancy (HDP) are one of the most common medical conditions that women encounter during pregnancy. Whether or not hypertensive disorders of pregnancy (HDP) are associated with allergic conditions in the offspring is unclear. This study used data from a large Japanese birth cohort to investigate whether HDP contributes to the development of allergic conditions in the offspring at 3 years. We also assessed the effect of blood pressure at different pregnancy trimesters on children's allergies.

Methods

We obtained data from the Japan Environment and Children's Study (JECS), which included 104 062 fetal records. After data selection, we analyzed 77 505 mother-child pairs, using logistic regression models to examine the relationships between HDP or the mother's blood pressure and their children's allergic conditions. In addition, we also evaluated the effect of HDP during pregnancy on allergies with a propensity score matched dataset, using a logistic regression model that predicts the conditional probability of whether a mother belonged to the HDP or non-HDP group.

Results

Among the 77 505 mothers eligible for analysis, 2334 (3.0%) had HDP. Percentages of women with hypertension were 1.7% in early gestation, 1.0% in mid-gestation, and 1.6% in late gestation. After adjusting for multiple potential confounders, HDP contributed nothing to allergy development in offspring. Children born to women with hypertension were no more likely than those without to have allergic conditions at 3 years of age. The propensity score matched dataset showed similar findings.

Conclusion

HDP and high blood pressure during pregnancy are apparently not risk factors for developing allergy in offspring. This information may help clinicians in counseling women who suffered HDP during pregnancy.

Gestational diabetes and childhood asthma in a racially diverse US pregnancy cohort

BACKGROUND

Childhood asthma is a common chronic disease that likely has prenatal origins. Gestational diabetes alters maternal physiology and may influence fetal risk for childhood-onset disease. However, the association between gestational diabetes and child asthma is not well characterized.

OBJECTIVE

To investigate the association between gestational diabetes and wheeze/asthma at approximately 4 years of age in a racially diverse US cohort.

METHODS

We studied mother-child dyads enrolled prenatally in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study. Gestational diabetes was determined by medical chart review. At approximately 4 years of age, we assessed child respiratory outcomes including parent report of physician-diagnosed asthma (ever), current wheeze (symptoms within the past 12 months), and current asthma (physician diagnosis and/or medication or symptoms within the past 12 months). We used the modified Poisson regression to assess associations between gestational diabetes and child respiratory outcomes, adjusting for maternal age, race, prenatal smoking, pre-pregnancy body mass index, parity, asthma history, socioeconomic status, and infant sex.

RESULTS

Among 1107 women, 66% were African American/Black. Six percent (n = 62) had gestational diabetes documented during pregnancy. Gestational diabetes was associated with increased risk of physician-diagnosed asthma (adjusted risk ratio (RR) [95% Confidence Interval]: 2.13 [1.35, 3.38]; prevalence: 14%), current wheeze (RR: 1.85 [1.23, 2.78]; prevalence: 19%), and current asthma (RR: 2.01 [1.30, 3.10]; prevalence: 16%).

CONCLUSIONS

Gestational diabetes was associated with increased risk of asthma and wheeze outcomes. Additional studies are needed to elucidate modifiable pathways underlying this association.

Perinatal High-Fat Diet Influences Ozone-Induced Responses on Pulmonary Oxidant Status and the Molecular Control of Mitophagy in Female Rat Offspring

Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machinery that controls receptor-mediated mitophagy. In female offspring, a perinatal HFD exacerbated these responses, whereas in male offspring, responses were similar for both diet groups. The expression of the genes and proteins involved in oxidative phosphorylation and mitochondrial biogenesis, fusion, and fission was not affected by ozone exposure or perinatal HFD. These findings suggest that a perinatal HFD influences ozone-induced responses on pulmonary oxidant status and the molecular control of mitophagy in female rat offspring.

Association between maternal diabetes mellitus and allergic diseases in children - A systematic review and meta-analysis

BACKGROUND

Existing knowledge suggests that gestational diabetes mellitus was inconsistently associated with offspring allergic diseases. The aim of this study was to identify the association between maternal diabetes mellitus and the risk of offspring allergic diseases by systematic review.

METHODS

We searched and retrieved three databases (PubMed, Web of Science, and Cochrane Library) for articles on the association between maternal diabetes mellitus and offspring allergic diseases published before December 31, 2019. Stata software version 16.0 was used for statistical analysis.

RESULTS

Eight published studies were included in this meta-analysis. The pooled effect estimates showed the association between maternal diabetes mellitus and allergic outcomes, including asthma (OR: 1.13, 95% CI: 1.01-1.27), wheezing (OR: 1.13, 95% CI: 1.07-1.21), and atopic dermatitis (OR: 1.43, 95% CI: 1.22-1.57). Maternal diabetes mellitus was not associated with the risk of allergic sensitization, with a pooled effect estimate of 1.07 (95% CI: 0.45, 2.58).

CONCLUSION

Maternal diabetes mellitus may increase the risk of allergic diseases in their children. However, this finding should be validated with future large-sample epidemiological studies covering a wider spectrum of allergic diseases.

Perinatal Nutritional and Metabolic Pathways: Early Origins of Chronic Lung Diseases

Lung development is not completed at birth, but expands beyond infancy, rendering the lung highly susceptible to injury. Exposure to various influences during a critical window of organ growth can interfere with the finely-tuned process of development and induce pathological processes with aberrant alveolarization and long-term structural and functional sequelae. This concept of developmental origins of chronic disease has been coined as perinatal programming. Some adverse perinatal factors, including prematurity along with respiratory support, are well-recognized to induce bronchopulmonary dysplasia (BPD), a neonatal chronic lung disease that is characterized by arrest of alveolar and microvascular formation as well as lung matrix remodeling. While the pathogenesis of various experimental models focus on oxygen toxicity, mechanical ventilation and inflammation, the role of nutrition before and after birth remain poorly investigated. There is accumulating clinical and experimental evidence that intrauterine growth restriction (IUGR) as a consequence of limited nutritive supply due to placental insufficiency or maternal malnutrition is a major risk factor for BPD and impaired lung function later in life. In contrast, a surplus of nutrition with perinatal maternal obesity, accelerated postnatal weight gain and early childhood obesity is associated with wheezing and adverse clinical course of chronic lung diseases, such as asthma. While the link between perinatal nutrition and lung health has been described, the underlying mechanisms remain poorly understood. There are initial data showing that inflammatory and nutrient sensing processes are involved in programming of alveolarization, pulmonary angiogenesis, and composition of extracellular matrix. Here, we provide a comprehensive overview of the current knowledge regarding the impact of perinatal metabolism and nutrition on the lung and beyond the cardiopulmonary system as well as possible mechanisms determining the individual susceptibility to CLD early in life. We aim to emphasize the importance of unraveling the mechanisms of perinatal metabolic programming to develop novel preventive and therapeutic avenues.

Factors and mechanisms contributing to the development of preschool wheezing disorders

INTRODUCTION

Half of all children will experience an episode of wheezing by their sixth birthday and acute episodes of wheezing in preschool children account for the majority of all childhood hospital admissions for wheeze. Recurrent preschool wheezing associates with early loss of lung function and a life-long impact on lung health.

AREAS COVERED

We reviewed the literature on PubMed from August 2010-2020 focussing on factors associated with wheeze inception and persistence, paying specific attention to mechanistic studies that have investigated the impact of early life exposures in shaping immune responses in children with underlying susceptibility to wheezing. In particular, the role of early allergen sensitization, respiratory infections, and the impact of the environment on shaping the airway microbiome and resulting immune responses are discussed.

EXPERT OPINION

There is an abundance of associative data showing the role of in utero and postnatal factors influencing wheeze onset and persistence. However, mechanistic and stratified, biomarker-based interventional studies that confirm these associations are now needed if we are to impact the significant healthcare burden resulting from preschool wheezing disorders.

Decreased Lymphangiogenic Activities and Genes Expression of Cord Blood Lymphatic Endothelial Progenitor Cells (VEGFR3+/Pod+/CD11b+ Cells) in Patient with Preeclampsia

The abnormal development or disruption of the lymphatic vasculature has been implicated in metabolic and hypertensive diseases. Recent evidence suggests that the offspring exposed to preeclampsia (PE) in utero are at higher risk of long-term health problems, such as cardiovascular and metabolic diseases in adulthood, owing to in utero fetal programming. We aimed to investigate lymphangiogenic activities in the lymphatic endothelial progenitor cells (LEPCs) of the offspring of PE. Human umbilical cord blood LEPCs from pregnant women with severe PE (n = 10) and gestationally matched normal pregnancies (n = 10) were purified with anti-vascular endothelial growth factor receptor 3 (VEGFR3)/podoplanin/CD11b microbeads using a magnetic cell sorter device. LEPCs from PE displayed significantly delayed differentiation and reduced formation of lymphatic endothelial cell (LEC) colonies compared with the LEPCs from normal pregnancies. LECs differentiated from PE-derived LEPCs exhibited decreased tube formation, migration, proliferation, adhesion, wound healing, and 3D-sprouting activities as well as increased lymphatic permeability through the disorganization of VE-cadherin junctions, compared with the normal pregnancy-derived LECs. In vivo, LEPCs from PE showed significantly reduced lymphatic vessel formation compared to the LEPCs of the normal pregnancy. Gene expression analysis revealed that compared to the normal pregnancy-derived LECs, the PE-derived LECs showed a significant decrease in the expression of pro-lymphangiogenic genes (GREM1, EPHB3, VEGFA, AMOT, THSD7A, ANGPTL4, SEMA5A, FGF2, and GBX2). Collectively, our findings demonstrate, for the first time, that LEPCs from PE have reduced lymphangiogenic activities in vitro and in vivo and show the decreased expression of pro-lymphangiogenic genes. This study opens a new avenue for investigation of the molecular mechanism of LEPC differentiation and lymphangiogenesis in the offspring of PE and subsequently may impact the treatment of long-term health problems such as cardiovascular and metabolic disorders of offspring with abnormal development of lymphatic vasculature.

The effect of gestational diabetes mellitus on the risk of asthma in offspring

PURPOSE

To examine the effect of maternal gestational diabetes mellitus on the risk of asthma in the offspring.

METHODS

This cohort study used data from 19,933 children in the National Longitudinal Survey of Children and Youth (NLSCY), 1994/1995-2008/2009, Canada. Children were followed until the first-time report of having health professional-diagnosed asthma (hereafter incident asthma), loss to follow-up, or end of the NLSCY follow-up, whichever occurred first. As a surrogate for Cox proportional hazards regression, pooled logistic regression models, crude and adjusted for potential confounders, were fitted to estimate the effect of gestational diabetes mellitus on the risk of asthma in the offspring.

RESULTS

Among the 19,933 children, 1,178 (5.9%) had mothers with gestational diabetes mellitus. The median duration of follow-up was 4 (interquartile range: 4) years. A total of 1639 children in the cohort had reported incident asthma during the follow-up, and 119 of them had mothers with gestational diabetes mellitus. The adjusted hazard ratio for the association between gestational diabetes mellitus and incident asthma in offspring was 1.25 (95% confidence interval [CI] 1.03, 1.51).

CONCLUSIONS

Our findings suggest that gestational diabetes mellitus increases the risk of asthma in the offspring.

Gestational Diabetes Mellitus and Developmental Programming

During normal pregnancy, increased insulin resistance acts as an adaptation to enhance materno-foetal nutrient transfer and meet the nutritional needs of the developing foetus, particularly in relation to glucose requirements. However, about 1 in 6 pregnancies worldwide is affected by the inability of the mother's metabolism to maintain normoglycaemia, with the combination of insulin resistance and insufficient insulin secretion resulting in gestational diabetes mellitus (GDM). A growing body of epidemiologic work demonstrates long-term implications for adverse offspring health resulting from exposure to GDM in utero. The effect of GDM on offspring obesity and cardiometabolic health may be partly influenced by maternal obesity; this suggests that improving glucose and weight control during early pregnancy, or better still before conception, has the potential to lessen the risk to the offspring. The consequences of GDM for microbiome modification in the offspring and the impact upon offspring immune dysregulation are actively developing research areas. Some studies have suggested that GDM impacts offspring neurodevelopmental and cognitive outcomes; confirmatory studies will need to separate the effect of GDM exposure from the complex interplay of social and environmental factors. Animal and human studies have demonstrated the role of epigenetic modifications in underpinning the predisposition to adverse health in offspring exposed to suboptimal hyperglycaemic in utero environment. To date, several epigenome-wide association studies in human have extended our knowledge on linking maternal diabetes-related DNA methylation marks with childhood adiposity-related outcomes. Identification of such epigenetic marks can help guide future research to develop candidate diagnostic biomarkers and preventive or therapeutic strategies. Longer-term interventions and longitudinal studies will be needed to better understand the causality, underlying mechanisms, or impact of GDM treatments to optimize the health of future generations.

Gestational hypertension and childhood atopy: a Millennium Cohort Study analysis

Gestational hypertension may confer risk of atopic disease in offspring through a direct biological mechanism, but another possibility is that risk is mediated through complications of pregnancy. To explore these associations, we conducted an analysis of a nationally representative birth cohort based in the UK involving children born 2000-2002. We included 12,450 mother-child pairs. We used logistic regression to estimate the association between hypertensive disease and asthma, hay fever, or eczema by age 5, and parentally reported early wheeze and severe wheeze. Mediation by gestation at delivery and caesarean delivery was explored using causal mediation analysis. Odds ratios (95% CI) for gestational hypertension and childhood asthma, hay fever, and eczema were 1.32 (1.09, 1.59), 1.22 (0.97, 1.55), and 1.12 (0.96, 1.32) respectively, adjusted for confounding. The population attributable fractions were 2.4% (1.0-3.8%), 0.9% (-0.3% to 2.1%), and 1.8% (0.0-3.7%), respectively. Accounting for mediation by gestational age and caesarean delivery, odds ratios (95% CI) for the potential direct effects of gestational hypertension were 1.21 (0.97, 1.50), 1.17 (0.91, 1.49), and 1.11 (0.94, 1.31) for the same.Conclusion: Gestational hypertension was weakly positively associated with asthma and this was partly mediated by earlier delivery. Only a small proportion of early childhood asthma was attributable to gestational hypertensive disease in this representative UK-based birth cohort. What is known: • Gestational hypertension has been shown to be an inconsistent risk factor for the atopic diseases. • The in utero immune environment may modify the risk of atopy in offspring; alternatively, complications of pregnancy including caesarean delivery and prematurity may explain an association between hypertensive disease and atopy. What is new: • Self-reported gestational hypertension was a weak risk factor for asthma and wheeze in the Millennium Cohort Study. • Part of the association between gestational hypertensive disease and asthma was explained by earlier delivery.

Association of Maternal Prepregnancy Weight and Gestational Weight Gain With Children's Allergic Diseases

IMPORTANCE

Information on the association between maternal prepregnancy body weight, gestational weight change, and childhood allergies is not consistent. Little is known on whether there is a combined association with comprehensive childhood allergies.

OBJECTIVE

To examine the association of maternal prepregnancy body mass index and gestational weight gain (GWG) with the risk of childhood allergic diseases including asthma and/or wheezing, allergic rhinitis, eczema, and food and/or drug allergy.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from April 12 to June 1, 2019, using the Shanghai Children Allergy Study (SCAS), a large, population-based survey. A multistage and multistrata sampling approach was applied to conduct the survey in 13 districts across Shanghai, China, with an enrollment of 15 145 mother-child pairs.

EXPOSURES

Reported maternal weight before pregnancy and at the time of delivery were requested in the survey; GWG was examined in absolute terms and with reference to the Institute of Medicine guideline.

MAIN OUTCOMES AND MEASURES

The ascertainment of allergic diseases was based on the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Among 15 145 children aged 3 to 14 years (7911 [52.2%] boys) within the SCAS, 8877 children (58.6%) were screened for allergic diseases. Multivariable log-binomial regression models suggested that excessive GWG was associated with risks of 19% for asthma/wheezing, 11% for allergic rhinitis, and 10% for eczema in the children. Gestational weight gain extremely above the Institute of Medicine guideline in women who were overweight/obese before pregnancy was associated with the highest risk of childhood asthma/wheezing (adjusted prevalence ratio, 1.42; 95% CI, 1.16-1.74; P = .001), allergic rhinitis (adjusted prevalence ratio, 1.32; 95% CI, 1.12-1.56; P = .001), and eczema (adjusted prevalence ratio, 1.24; 95% CI, 1.08-1.41; P = .002). Gestational weight gain below the Institute of Medicine guideline was associated with an attenuated risk of 13% for childhood asthma/wheezing, 11% for allergic rhinitis, 14% for eczema, and 15% food/drug allergy when mothers were of prepregnancy normal weight; similar associations were observed in underweight mothers, but there was no association in overweight mothers. Generally, the associations were similar in the stratified analysis according to children's age group. Moreover, the results were similar in the allergen test subgroup.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that excessive GWG may be a risk factor for childhood allergic diseases. Further studies on the long-term effects of the intrauterine environment on children's health may take maternal weight management during pregnancy into consideration since GWG could be a controllable and modifiable risk factor.

Measuring Child Socio-Economic Position in Birth Cohort Research: The Development of a Novel Standardized Household Income Indicator

The assessment of early life socioeconomic position (SEP) is essential to the tackling of social inequalities in health. Although different indicators capture different SEP dimensions, maternal education is often used as the only indicator in birth cohort research, especially in multi-cohort analyses. Household income, as a direct measure of material resources, is one of the most important indicators, but one that is underused because it is difficult to measure through questionnaires. We propose a method to construct a standardized, cross-cohort comparable income indicator, the “Equivalized Household Income Indicator (EHII)”, which measures the equivalized disposable household income, using external data from the pan-European Union Statistics on Income and Living Conditions (EUSILC) surveys, and data from the cohorts. We apply this method to four studies, Piccolipiù and NINFEA from Italy and ELFE and EDEN from France, comparing the distribution of EHII with other SEP-related variables available in the cohorts, and estimating the association between EHII and child body mass index (BMI). We found that basic parental and household characteristics may be used, with a fairly good performance, to predict the household income. We observed a strong correlation between EHII and both the self-reported income, whenever available, and other individual socioeconomic-related variables, and an inverse association with child BMI. EHII could contribute to improving research on social inequalities in health, in particular in the context of European birth cohort collaborative studies.

Birth weight and prematurity with lung function at ~17.5 years: "Children of 1997" birth cohort

We aimed to determine if prematurity and lower birth weight are associated with poorer lung function in a non-western developed setting with less marked confounding by socioeconomic position. Using multivariable linear regression in Hong Kong’s “Children of 1997” birth cohort, adjusted associations of prematurity and birth weight with forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and forced expiratory flow at 25–75% of the pulmonary volume (FEF_25–75%) at ~17.5 years were assessed. Associations for birth weight were stronger in boys for FEV₁ (boys: 0.31 L, 95% confidence interval (CI) 0.24 to 0.38, girls: 0.18 L, 95% CI 0.12 to 0.25), FVC (boys: 0.36 L, 95% CI 0.27 to 0.44, girls: 0.22 L, 95% CI 0.15 to 0.28) and FEF_25–75% (boys: 0.35 L, 95% CI 0.21 to 0.49, girls: 0.22 L, 95% CI 0.09 to 0.34) adjusted for age, socioeconomic position and infant and maternal characteristics. Similarly adjusted, preterm birth (compared to full-term birth) was associated with lower FEV₁/FVC and FEF_25–75%. Thus, associations of lower birth weight, especially in boys, and prematurity with poorer lung function at 17.5 years were found. Identifying underlying mechanism might contribute to the improvement of pulmonary health and the prevention of adult respiratory illness.

Association of biomass fuel smoke with respiratory symptoms among children under 5 years of age in urban areas: results from Bangladesh Urban Health Survey, 2013

BACKGROUND

Little is known regarding the effect of exposure to biomass fuel smoke inhalation on respiratory symptoms in the Bangladeshi population which is a major health hazard in most of the developing countries. This study aims to explore the association between respiratory symptoms and biomass fuel smoke exposure among children under 5 years of age.

METHODS

Data were extracted from the Bangladesh Urban Health Survey conducted in 2013. A total of 10,575 mothers with at least one surviving children were selected. Respiratory symptoms among children under 5 years of age were considered as the primary outcome. Sequential multiple logistic regression models were used to observe the association between respiratory symptoms and biomass fuel smoke exposure adjusting the effect of residential factors and mother and child characteristics.

RESULTS

Around 40% of the mothers exclusively used biomass fuel irrespective of the kitchen location and 54% of them were habituated in indoor cooking. The prevalence of respiratory symptoms of under-five children among in-house and outdoor biomass fuel users was 23.0% and 21.9%, respectively. Results of fitted multiple logistic regression models showed that the odds of having respiratory symptoms among children under 5 years of age were increased due to in-house biomass fuel use [OR = 1.18; 95% CI, 1.04-1.36] compared with the non-biomass user. An increased risk of respiratory symptoms was also significantly associated with mother's birth complication [OR = 1.51; 95% CI, 1.36-1.67], non-government organization (NGO) membership of mothers [OR = 1.32; 95% CI, 1.16-1.51], age of the child (6-23m) [OR = 1.29; 95% CI, 1.10-1.52], and nutritional status (stunting) [OR = 1.18; 95% CI, 1.06-1.31].

CONCLUSION

This study found the use of in-house biomass fuel as a significant risk factor associated with respiratory symptoms of children under 5 years of age. More longitudinal studies should be designed to establish a causal relationship between HAP (household air pollution) and respiratory symptoms among children with more direct measures of HAP and clinical procedure.

Maternal obesity and gestational diabetes decrease Metrnl concentrations in cord plasma

OBJECTIVE

To determine the effect of preexisting maternal obesity and gestational diabetes mellitus (GDM) on the circulating levels of Metrnl in cord and maternal plasma.

DESIGN

Metrnl levels were measured on maternal and cord plasma from women with normal glucose tolerance (NGT) (19 non-obese and 20 obese), GDM controlled by diet (18 non-obese and 17 obese) and GDM controlled by insulin (19 non-obese and 18 obese) at the time of term elective cesarean section. Metrnl concentrations were determined by enzyme-linked immunoassay. Correlations of Metrnl levels with anthropometric parameters and laboratory measurements were also assessed.

RESULTS

There was no effect of maternal obesity or GDM on maternal plasma Metrnl concentrations. In cord plasma, Metrnl concentrations were significantly lower in NGT obese compared to NGT non-obese women and in non-obese GDM women compared to non-obese NGT women. Significant positive correlations were observed between maternal plasma Metrnl and cord plasma Metrnl. In cord plasma, significant positive correlations were observed between Metrnl levels and GWG and maternal and cord plasma glucose levels at delivery.

CONCLUSIONS

At the time of term cesarean section, preexisting maternal obesity and GDM are associated with lower Metrnl levels in cord plasma. Alterations in cord plasma Metrnl levels may lead to alterations in fetal growth trajectory and be a determinant for metabolic disorders later in life.

Influences of Maternal Factors Over Offspring Allergies and the Application for Food Allergy

The prevalence of food allergy has been steadily rising worldwide with the highest incidence noted among younger children, and increasingly recognized as a growing public concern. The first known ingestion of foods often causes allergic reaction, suggesting that sensitization of offspring with food allergens may occur during pregnancy and/or through breastfeeding. This creates a milieu that shapes the neonatal immune responses to these allergens. However, the effects of maternal allergen exposure and maternal sensitization with allergens on development of allergies in offspring remain controversial. This review discusses recent advances from human data in our understanding of how maternal factors, namely, food allergens, allergen-specific immunoglobulins, cytokines, genetics, and environmental factors transferred during pregnancy or breastfeeding influence offspring allergies and how such effects may be applicable to food allergy. Based on information obtained from mouse models of asthma and food allergy, the review also dissects the mechanisms by which maternal factors, including the impact of immune complexes, transforming growth factor-β, vitamin A, and regulatory T-cell responses, contribute to the induction of neonatal tolerance vs. development of allergic responses to maternally transferred allergens.

Fetal umbilical, cerebral and pulmonary blood flow patterns in relation to lung function and asthma in childhood. The Generation R Study

BACKGROUND

Fetal growth restriction is associated with higher risks of childhood respiratory morbidity. Fetal blood flow adaptations might contribute to these associations. We examined the associations of fetal umbilical, cerebral, and pulmonary blood flow with wheezing patterns, lung function, and asthma in childhood.

METHODS

In a population-based prospective cohort study among 903 children, we measured fetal umbilical, cerebral, and pulmonary blood flow by pulsed-wave Doppler at a median gestational age of 30.3 (95% range 28.8-32.3) weeks. We obtained information about wheezing patterns until the age of 6 years by questionnaires. Lung function was measured by spirometry and information about current asthma was obtained by questionnaire at the age of 10 years.

RESULTS

Results showed a non-significant relationship between a higher umbilical artery pulsatility index (PI) and umbilical artery PI/cerebral artery PI ratio, indicating fetal blood flow redistribution at the expense of the trunk, with higher risks of early wheezing (OR [95% CI]: 2.07 (0.70-6.10) and 2.74 (0.60, 12.62) per unit increase, respectively). A higher pulmonary artery time velocity integral, indicating higher pulmonary vascular resistance, was associated with a higher risk of late/persistent wheezing (Z-score 1.14 [1.01-1.29]). A higher middle cerebral artery PI was associated with a higher FEV1 /FVC (Z-score [95% CI]: 0.21 [0.01-0.42]). Results did not materially change after additional adjustment for birth and growth characteristics.

CONCLUSION

Third-trimester fetal blood flow patterns might be related to childhood respiratory health. These findings should be considered as hypothesis generating and need further replication.

Maternal blood pressure and hypertensive disorders during pregnancy and childhood respiratory morbidity: the Generation R Study

Pre-eclampsia is associated with an increased risk of bronchopulmonary dysplasia, wheezing and asthma in later childhood. Currently, there are no studies available investigating maternal blood pressure measurements during multiple time-points in pregnancy and respiratory outcome measures in the child.We examined the associations of maternal blood pressure and hypertensive disorders with the risk of lower lung function, wheezing and asthma in children aged 10 years. This study among 4894 children was embedded in a population-based prospective cohort study. We used multivariate analyses, taking lifestyle and socioeconomic factors into account.We observed consistent associations per 5 mmHg higher maternal blood pressure in early pregnancy with a lower forced expiratory volume in 1 s/forced vital capacity ratio (z-score -0.03 (95% CI -0.05- -0.01)) and per 5 mmHg higher blood pressure in late pregnancy with a higher risk for current wheezing and current asthma (OR 1.07 (95% CI 1.02-1.12) and 1.06 (95% CI 1.00-1.11), respectively). We found no associations of maternal hypertensive disorders during pregnancy with child lung function, current wheezing or current asthma.Our results suggest that higher blood pressure in pregnant women is associated with lower lung function and increased risks of current wheezing and current asthma in children. The associations may be trimester specific.

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.

Does early onset asthma increase childhood obesity risk? A pooled analysis of 16 European cohorts

The parallel epidemics of childhood asthma and obesity over the past few decades have spurred research into obesity as a risk factor for asthma. However, little is known regarding the role of asthma in obesity incidence. We examined whether early-onset asthma and related phenotypes are associated with the risk of developing obesity in childhood.This study includes 21 130 children born from 1990 to 2008 in Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden and the UK. We followed non-obese children at 3-4 years of age for incident obesity up to 8 years of age. Physician-diagnosed asthma, wheezing and allergic rhinitis were assessed up to 3-4 years of age.Children with physician-diagnosed asthma had a higher risk for incident obesity than those without asthma (adjusted hazard ratio (aHR) 1.66, 95% CI 1.18-2.33). Children with active asthma (wheeze in the last 12 months and physician-diagnosed asthma) exhibited a higher risk for obesity (aHR 1.98, 95% CI 1.31-3.00) than those without wheeze and asthma. Persistent wheezing was associated with increased risk for incident obesity compared to never wheezers (aHR 1.51, 95% CI 1.08-2.09).Early-onset asthma and wheezing may contribute to an increased risk of developing obesity in later childhood.

Maternal pre-eclampsia and long-term offspring health: Is there a shadow cast?

Pre-eclampsia is a common pregnancy disorder with important short-term complications for mother and baby. Evidence suggests pre-eclampsia also has implications for the mother beyond pregnancy, as well as long-term effects on offspring health. Limited research has linked pre-eclampsia with changes in offspring blood pressure, BMI, and stroke risk. Underpinning mechanisms are poorly understood, but developmental programming may be involved. Research in this area has been hindered by difficulties in defining pre-eclampsia and problems with study design. Further targeted evaluation through to adulthood is required to determine the long-term impact of pre-eclampsia on offspring disease risk and how this develops.

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.

Maternal obesity and childhood wheezing and asthma

Obesity represents one of the major public health problems worldwide, with an increased prevalence also among women of reproductive age. Maternal pre-pregnancy overweight and obesity are important risk factors for a number of maternal and foetal/neonatal complications. The objective of this review is to provide an overview of the most recent evidence regarding the associations between pre-pregnancy overweight/obesity and wheezing and asthma in childhood. Potential mechanisms, mediators and confounding factors involved in these associations are also discussed. Despite the relatively large body of studies examining these associations and taking into account main confounders and potential mediators, the causal relationship between maternal obesity and wheezing and asthma in childhood is still uncertain. This uncertainty is not trivial, as any prevention strategy aimed at reducing the burden of these conditions would necessarily imply better understanding of the factors that are in the causal chain.

Diabetes in pregnancy and lung health in offspring: developmental origins of respiratory disease

Diabetes is an increasingly common complication of pregnancy. In parallel with this trend, a rise in chronic lung disease in children has been observed in recent decades. While several adverse health outcomes associated with exposure to diabetes in utero have been documented in epidemiological and experimental studies, few have examined the impact of diabetes in pregnancy on offspring lung health and respiratory disease. We provide a comprehensive overview of current literature on this topic, finding suggestive evidence that exposure to diabetes in utero may have adverse effects on lung development. Delayed lung maturation and increased risk of respiratory distress syndrome have been consistently observed among infants born to mothers with diabetes and these findings are also observed in some rodent models of diabetes in pregnancy. Further research is needed to confirm and characterize epidemiologic observations that diabetes in pregnancy may predispose offspring to childhood wheezing illness and asthma. Parallel translational studies in human pregnancy cohorts and experimental models are needed to explore the role of fetal programming and other potential biological mechanisms in this context.

Pre-eclampsia and childhood asthma

Studies of pre-eclampsia and childhood asthma are conflicting, and none have performed a formal mediation analysis of preterm birth.We examined the association between pre-eclampsia and asthma at 7 years using national registries, including all births in Norway from 1999 to 2006 (n=406 907), and a subsample of children in the Norwegian Mother and Child Cohort Study (MoBa) (n=45 028) using log-linear regression. We performed a mediation analysis of preterm birth, and a sibling comparison to evaluate unobserved confounding.There was a positive association between pre-eclampsia and asthma in the registry study, with an adjusted relative risk of 1.31 (95% CI 1.22-1.41), but not in MoBa, which had an adjusted relative risk of 1.19 (95% CI 0.99-1.44). The odds ratios for the direct effect not mediated through preterm birth and the indirect effect in the registry linkage were 1.19 (95% CI 1.10-1.29) and 1.12 (95% CI 1.11-1.14), respectively. The sibling comparison indicated no association between pre-eclampsia and asthma (adjusted OR 1.07, 95% CI 0.87-1.33).In this large study, which used different datasets and analytic approaches, there was little evidence for an association between pre-eclampsia and childhood asthma. The association was weak and largely explained by pre-term birth and confounders shared by siblings.

Longitudinal study of maternal body mass index, gestational weight gain, and offspring asthma

BACKGROUND

Sparse data are available on the relationship between prenatal exposures and asthma during later childhood. In a longitudinal study of adolescents and their mothers, we examined the association of (i) maternal prepregnancy body mass index (BMI) and (ii) gestational weight gain (GWG), with incidence of allergic and nonallergic asthma in offspring.

METHODS

Analyses were conducted using data from 12 963 children aged 9-14 years at enrolment in the Growing Up Today Study, and their mothers, who are participants in the Nurses' Health Study II. Physician-diagnosed asthma and allergies were assessed by questionnaires sent regularly to participants and their mothers. Logistic regression was used to evaluate associations of maternal BMI and GWG with offspring asthma, overall and by subtype.

RESULTS

Physician-diagnosed asthma during childhood or adolescence was reported by 2694 children (21%). Maternal prepregnancy overweight (OR: 1.19, 95% CI: 1.03-1.38) and obesity (1.34, 1.08-1.68) were associated with offspring asthma. In asthma subtype analyses, the association was seen only for asthma onset before age 12 years. Moreover, the association of maternal obesity with nonallergic asthma was observed in boys (2.39, 1.40-4.09) and not in girls (0.96, 0.50-1.85; Pinteraction = 0.03); the opposite pattern was suggested for allergic asthma. With regard to GWG, an association was suggested between gains of <15 lb and higher risk of offspring asthma (1.28, 0.98-1.66), without clear allergy- or sex-related patterns.

CONCLUSION

The relation of several prenatal factors to risk of childhood asthma supports the early origins hypothesis for asthma. The observed allergy- and sex-specific patterns suggest multiple etiologic pathways.

Maternal Obesity Affects Inflammatory and Iron Indices in Umbilical Cord Blood

OBJECTIVE

To determine the impact of maternal obesity and gestational weight gain across pregnancy on fetal indices of inflammation and iron status.

STUDY DESIGN

Eighty-five healthy term newborns delivered via elective cesarean were categorized by 2 maternal body mass index (BMI) thresholds; above or below 30 kg/m(2) or above or below 35 kg/m(2). Umbilical cord plasma levels of C-reactive protein, interleukin (IL)-6, tumor necrosis factor (TNF)-α, ferritin, and hepcidin were assayed. Cytokines released by phytohemagglutinin-stimulated umbilical cord mononuclear cells (MNCs) were assayed.

RESULTS

Maternal class II obesity, defined as BMI of 35 kg/m(2) and above, predicted higher C-reactive protein and TNF-α in umbilical cord plasma (P < .05 for both), and also proinflammatory cytokines (IL-1β, IL-6, and TNF-α) from stimulated MNC (P < .05 for all). The rise in plasma TNF-α and MNC TNF-α was not linear but occurred when the threshold of BMI 35 kg/m(2) was reached (P < .005, P < .06). Poorer umbilical cord iron indices were associated with maternal obesity. When ferritin was low, IL-6 was higher (P < .04), but this relationship was present primarily when maternal BMI exceeded 35 kg/m(2) (P < .03). Ferritin was correlated with hepcidin (P < .0001), but hepcidin was unrelated to either maternal BMI or inflammatory indices.

CONCLUSIONS

Class II obesity and above during pregnancy is associated with fetal inflammation in a threshold fashion. Although maternal BMI negatively impacted fetal iron status, hepcidin, related to obesity in adults, was related to iron status and not obesity in fetuses. Pediatricians should be aware of these relationships.

Key paediatric messages from Amsterdam

The Paediatric Assembly of the European Respiratory Society (ERS) maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress.

Hypertensive disorders of pregnancy, respiratory outcomes and atopy in childhood

Few epidemiological studies have investigated the role of hypertensive disorders of pregnancy in the aetiology of childhood respiratory and atopic outcomes.In the Avon Longitudinal Study of Parents and Children we examined associations of maternal gestational hypertension, hypertension before pregnancy and pre-eclampsia with wheezing at 18 months, wheezing and asthma at 7 years and lung function at 8-9 years, after controlling for potential confounders (n=5322-8734, depending on outcome).Gestational hypertension was not associated with any of the outcomes. There was weak evidence for a positive association between pre-eclampsia and early wheezing (adjusted OR 1.31, 95% CI 0.94-1.82, compared to normotensive pregnancies) and for negative associations between pre-eclampsia and forced expiratory volume in 1 s (adjusted mean difference in sd score -0.14, 95% CI -0.33-0.06) and maximal mid-expiratory flow (-0.15, 95% CI -0.34-0.04). Hypertension before pregnancy was positively associated with wheezing (OR 1.63, 95% CI 1.16-2.31) and asthma (OR 1.34, 95% CI 1.00-1.79).Gestational hypertension is unlikely to be a risk factor for childhood respiratory disorders; hypertension before pregnancy may be a risk factor for childhood wheezing and asthma, but this finding needs replication. Larger studies are needed to confirm whether pre-eclampsia is associated with impaired childhood lung function.