Maternal pre-pregnancy obesity and diagnosis of asthma in offspring at age 3 years

Maternal Bariatric Surgery and Offspring Health: A Sibling Matched Analysis Comparing Offspring Born before and after the Surgery

(1) Background: Due to the global escalation in the prevalence of obesity, bariatric surgeries have become a popular solution in many western countries. The aim of the current study was to compare offspring health and the obesity of women before and after undergoing bariatric surgeries. (2) Methods: A retrospective population-based study was performed, including all singleton deliveries which occurred at a tertiary medical center between the years 1991-2021. Among women who had bariatric surgeries, the health of the offspring born before and after the surgery were compared. The offspring were followed up until the age of 18 years, and their hospitalization records were summarized. The incidence of hospitalization with either endocrine, cardiac, respiratory, neurologic, or infectious diagnoses were compared between the groups, as well as offspring obesity. Multivariable Cox proportional models were used to match between siblings and to address confounding variables, including maternal age, gestational age at delivery, fertility treatment, smoking and pregnancy hypertensive disorders. (3) Results: The study population included 3074 deliveries of women who underwent bariatric surgeries (1586 were before and 1488 after the surgery). Offspring born after maternal bariatric surgeries were at a comparable risk for most morbidities, besides endocrine-related morbidities (3.1% vs. 5.0%, OR = 1.61; 1.1-2.35) and obesity (2.5% vs. 4.1%, OR = 1.63; 1.08-2.48). The risk for these morbidities was higher among the offspring of mothers after, vs. before, the surgery, despite adjustment for maternal age and other confounding variables. (4) Conclusions: While bariatric surgeries are considered an effective treatment for obesity, it seems to have less of an effect on the offspring of women who underwent such surgeries. Other persistent factors are most likely associated with the offspring's risk for morbidities, especially endocrine morbidities and obesity, which remain even though the mother underwent bariatric surgeries.

From Beneath the Skin to the Airway Wall: Understanding the Pathological Role of Adipose Tissue in Comorbid Asthma-Obesity

This article provides a contemporary report on the role of adipose tissue in respiratory dysfunction. Adipose tissue is distributed throughout the body, accumulating beneath the skin (subcutaneous), around organs (visceral), and importantly in the context of respiratory disease, has recently been shown to accumulate within the airway wall: "airway-associated adipose tissue." Excessive adipose tissue deposition compromises respiratory function and increases the severity of diseases such as asthma. The mechanisms of respiratory impairment are inflammatory, structural, and mechanical in nature, vary depending on the anatomical site of deposition and adipose tissue subtype, and likely contribute to different phenotypes of comorbid asthma-obesity. An understanding of adipose tissue-driven pathophysiology provides an opportunity for diagnostic advancement and patient-specific treatment. As an exemplar, the potential impact of airway-associated adipose tissue is highlighted, and how this may change the management of a patient with asthma who is also obese. © 2023 American Physiological Society. Compr Physiol 13:4321-4353, 2023.

Relation of Maternal Pre-Pregnancy Factors and Childhood Asthma: A Cross-Sectional Survey in Pre-School Children Aged 2-5 Years Old

Background and Objectives: Asthma constitutes a constant, prolonged, inflammation-related pulmonary disorder in childhood with serious public health concerns. Several maternal risk factors can enhance the prevalence of its development in this stage of life; however, the currently available data remain contradictory and/or inconsistent. We aim to evaluate the potential impacts of mothers' sociodemographic, anthropometric and prenatal and perinatal factors on the prevalence of developing asthma in pre-school children. Materials and Methods: This is a retrospective cross-sectional survey, which includes 5133 women and their matched pre-school children. Childhood asthma was diagnosed using validated questionnaires. Statistical analysis was accomplished to evaluate whether maternal sociodemographic, anthropometric and prenatal and perinatal factors can increase the probability of childhood asthma in pre-school age. Results: A prevalence of 4.5% of childhood asthma was recorded in pre-school age. Maternal age and pre-pregnancy overweight and obesity, caesarean section, gestational diabetes and hypertension and not breastfeeding were associated with childhood asthma after adjustment for multiple confounding factors. Conclusion: Our research showed that several maternal factors increase the prevalence of childhood asthma in pre-school age. Suitable and effective health policies and strategies should be taken into account to confront the predominant maternal factors that increase its prevalence in pre-school age.

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.

Prepregnancy body mass index and risk of childhood asthma

BACKGROUND

Growing evidence suggests that maternal obesity may affect the intrauterine environment and increase a child's risk of developing asthma. We aim to investigate the relationship between prepregnancy obesity and childhood asthma risk.

METHODS

Cohorts of children enrolled in Kaiser Permanente Northern California integrated healthcare system were followed from birth (2005-2014) to age 4 (n = 104,467), 6 (n = 63,084), or 8 (n = 31,006) using electronic medical records. Child's asthma was defined using ICD codes and asthma-related prescription medication dispensing. Risk ratios (RR) and 95% confidence intervals (95% CIs) for child's asthma were estimated using Poisson regression with robust error variance for (1) prepregnancy BMI categories (underweight [<18.5], normal [18.5-24.9], overweight [25-29.9], obese 1 [30-34.9], and obese 2/3 [≥35]) and (2) continuous prepregnancy BMI modeled using cubic splines with knots at BMI category boundaries. Models were adjusted for maternal age, education, race, asthma, allergies, smoking, gestational weight gain, child's birth year, parity, infant sex, gestational age, and child's BMI.

RESULTS

Relative to normal BMI, RRs (95%CIs) for asthma at ages 4, 6, and 8 were 0.91 (0.75, 1.11), 0.95 (0.78, 1.16), and 0.97 (0.75, 1.27) for underweight, 1.06 (0.99, 1.14), 1.08 (1.01, 1.16), and 1.03 (0.94, 1.14) for overweight, 1.09 (1.00, 1.19), 1.12 (1.03, 1.23), 1.03 (0.91, 1.17) for obese 1, and 1.10 (0.99, 1.21), 1.13 (1.02, 1.25), 1.14 (0.99, 1.31) for obese 2/3. When continuous prepregnancy BMI was modeled with splines, child's asthma risk generally increased linearly with increasing prepregnancy BMI.

CONCLUSIONS

Higher prepregnancy BMI is associated with modestly increased childhood asthma risk.

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 pre-pregnancy body mass index and mental health problems in early adolescents from the 2004 Pelotas birth cohort

Possible mechanisms by which maternal pre-pregnancy body mass index (BMI) programs offspring mental disorders in late childhood are not fully clarified. To assess the association between maternal BMI and mental health problems at 11 years old, we used data from the 2004 Pelotas birth cohort which comprised 4231 newborns. Maternal pre-pregnancy BMI was analyzed as underweight (< 18.5), normal (18.5-24.9), overweight (25.0-29.9), and obesity (≥ 30.0). Mental health problems were assessed at the child's age of 11 years by the Strengths and Difficulties Questionnaire, total difficulties score and subscale scores (emotional symptoms, conduct problems, hyperactivity/inattention, and peer relationship problems), dichotomized into normal/borderline and abnormal category. The associations between maternal pre-pregnancy BMI and mental health problems in the whole sample and stratified by sex were estimated using crude and adjusted linear and logistic regression. Both linear and logistic regression showed that pre-pregnancy weight was associated with mental problems in early adolescents. Maternal pre-pregnancy obesity was associated with increased odds of total difficulty score among the whole sample. Boys whose mothers were pre-pregnancy overweight had higher odds of conduct problems (OR = 1.56; 95% CI: 1.13, 1.95), when compared to children of normal pre-pregnancy weight mothers, even after adjustments. Maternal pre-pregnancy obesity was associated with mental health problems in early adolescents; specifically, pre-pregnancy overweight increased the risk for conduct problems in 11 years old boys.

Examining the role of pre-pregnancy weight and gestational weight gain in allergic disease development among offspring: A population-based cohort study in Ontario, Canada

BACKGROUND

Studies suggest maternal weight and weight gain during pregnancy may influence foetal immunological development. However, their role in the aetiology of allergic disease is unclear.

OBJECTIVES

We sought to examine the impact of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on the incidence of four common paediatric allergic diseases.

METHODS

We conducted a retrospective, population-based cohort study of all singleton live births in Ontario, Canada between 2012 and 2014, using maternal-newborn records from the provincial birth registry linked with health administrative databases. Neonates were followed up to 7 years for anaphylaxis, asthma, dermatitis and rhinitis, identified through validated algorithms based on healthcare encounters. We multiply imputed missing data and employed Cox proportional-hazards models to calculate adjusted hazard ratios (aHR) with 95% confidence intervals (CI). To test the robustness of our findings, we also conducted several sensitivity analyses, including probabilistic bias analyses for exposure and outcome misclassification. All methods were prespecified in a published protocol.

RESULTS

Of the 248,017 infants followed, 52% were born to mothers with a pre-pregnancy BMI in the normal range and only 19% were born to mothers with adequate weight gain during pregnancy. Incidence rates (per 100,000 person-days) for anaphylaxis, asthma, dermatitis and rhinitis were 0.22, 6.80, 12.41 and 1.54, respectively. Compared with normal BMI, maternal obesity was associated with increased hazards of asthma in offspring (aHR 1.08, 95% CI 1.05, 1.11), but decreased hazards of anaphylaxis (aHR 0.83, 95% CI 0.69, 0.99) and dermatitis (aHR 0.97, 95% CI 0.94, 0.99). In contrast, maternal underweight was associated with increased hazards of dermatitis (aHR 1.06, 95% CI 1.02, 1.10). We found no associations between pre-pregnancy BMI and rhinitis or GWG and any allergic outcome, and no evidence of effect measures modification by infant sex.

CONCLUSIONS

These findings provide support for the involvement of maternal pre-pregnancy BMI in paediatric allergic disease development.

Fetal-Derived Immune Cells at the Roots of Lifelong Pathophysiology

Tissue-resident innate immune cells exert a wide range of functions in both adult homeostasis and pathology. Our understanding of when and how these cellular networks are established has dramatically changed with the recognition that many lineages originate at least in part from fetal sources and self-maintain independently from hematopoietic stem cells. Indeed, fetal-derived immune cells are found in most organs and serous cavities of our body, where they reside throughout the entire lifespan. At the same time, there is a growing appreciation that pathologies manifesting in adulthood may be caused by adverse early life events, a concept known as “developmental origins of health and disease” (DOHaD). Yet, whether fetal-derived immune cells are mechanistically involved in DOHaD remains elusive. In this review, we summarize our knowledge of fetal hematopoiesis and its contribution to adult immune compartments, which results in a “layered immune system.” Based on their ontogeny, we argue that fetal-derived immune cells are prime transmitters of long-term consequences of prenatal adversities. In addition to increasing disease susceptibility, these may also directly cause inflammatory, degenerative, and metabolic disorders. We explore this notion for cells generated from erythro-myeloid progenitors (EMP) produced in the extra-embryonic yolk sac. Focusing on macrophages and mast cells, we present emerging evidence implicating them in lifelong disease by either somatic mutations or developmental programming events resulting from maternal and early environmental perturbations.

Examining the effects of pre-pregnancy weight and gestational weight gain on allergic disease development in offspring: a protocol for a population-based study using health administrative databases in Ontario, Canada

INTRODUCTION

Over the last 20 years, excess maternal pre-pregnancy weight (overweight and obesity) and gestational weight gain have become the most common morbidities in pregnancy. These morbidities may pose a threat to fetal immunological development through associated metabolic dysfunction and inflammation and, as such, may partly explain the concurrent rise of paediatric allergic disease. We will examine the effect of maternal pre-pregnancy weight and gestational weight gain during pregnancy on the incidence of allergic diseases among offspring in Canada's most populous province.

METHODS AND ANALYSIS

We will conduct a retrospective, population-based cohort study of all singleton live births to residents of Ontario, Canada in 2012-2013 and 2013-2014. The study population will be defined using maternal-newborn records from the provincial birth registry, which captures information on maternal pre-pregnancy weight and gestational weight gain. The cohort will be linked with provincial health administrative databases, allowing for follow-up of neonates through early childhood until 2019 (5-7 years of age). Allergic disease development (asthma, rhinitis, atopic dermatitis and anaphylaxis) will be ascertained using diagnostic codes from healthcare encounters. Potential confounders have been identified a priori through a directed acyclic graph. Cox proportional hazards regression models will be employed to assess the associations between maternal pre-pregnancy weight, gestational weight gain and incident paediatric allergic disease. Several preplanned sensitivity analyses will be conducted, including a probabilistic bias analysis of outcome misclassification.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Research Ethics Board of the Children's Hospital of Eastern Ontario and the ICES Privacy Office. Findings will be disseminated in scientific conference presentations and peer-reviewed publications.

Developmental programming of peripheral diseases in offspring exposed to maternal obesity during pregnancy

Obesity is an increasing global health epidemic that affects all ages, including women of reproductive age. During pregnancy, maternal obesity is associated with adverse pregnancy outcomes that lead to complications for the mother. In addition, maternal obesity can increase the risk of poor perinatal outcomes for the infant due to altered development. Recent research has investigated the effects of maternal obesity on peripheral organ development and health in later life in offspring. In this review, we have summarized studies that investigated the programming effects of maternal obesity before and during pregnancy on metabolic, cardiovascular, immune, and microbiome perturbations in offspring. Epidemiological studies investigating the effects of maternal obesity on offspring development can be complex due to other copathologies and genetic diversity. Animal studies have provided some insights into the specific mechanisms and pathways involved in programming peripheral disease risk. The effects of maternal obesity during pregnancy on offspring development are often sex specific, with sex-specific changes in placental transport and function suggestive that this organ is likely to play a central role. We believe that this review will assist in facilitating future investigations regarding the underlying mechanisms that link maternal obesity and offspring disease risk in peripheral organs.

Associations of α- and γ-tocopherol during early life with lung function in childhood

BACKGROUND

Tocopherol isoforms may regulate child lung growth and spirometric measures.

OBJECTIVE

Our aim was to determine the extent to which plasma α-tocopherol (α-T) or γ-tocopherol (γ-T) isoform levels in early childhood or in utero are associated with childhood lung function.

METHODS

We included 622 participants in the Project Viva cohort who had lung function at a mid-childhood visit (age 6-10 years). Maternal and child tocopherol isoform levels were measured by HPLC at the second trimester and 3 years of age, respectively. Multivariable linear regression models (adjusted for mid-childhood body mass index z scores, maternal education, smoking in pregnancy, and prenatal particulate matter with diameter of <2.5 micrometers (PM_2.5) particulate exposure) stratified by tertiles of child γ-T level were used to assess the association of α-T levels with FEV₁ and forced vital capacity (FVC) percent predicted. Similarly, models stratified by child α-T tertile evaluated associations of γ-T levels with lung function. We performed similar analyses with maternal second trimester tocopherol isoform levels.

RESULTS

The median maternal second trimester α-T level was 63 μM (interquartile range = 47-82). The median early-childhood level was 25 μM (interquartile range = 20-33 μM). In the lowest tertile of early-childhood γ-T, children with a higher α-T level (per 10 μM) had a higher mid-childhood FEV₁ percent predicted (β = 3.09; 95% CI = 0.58-5.59 and a higher FVC percent predicted (β = 2.77; 95% CI = 0.47-5.06). This protective association of α-T was lost at higher γ-T levels. We did not see any consistent associations of second trimester levels of either α-T or γ-T with mid-childhood FEV₁ or FVC.

CONCLUSION

When γ-T levels were in the lowest tertile, a higher early-childhood α-T level was associated with better lung function at mid-childhood. Second trimester maternal plasma α-T concentration was 3-fold higher than in the adult nonpregnant female population.

Pre-pregnancy Maternal Weight and Gestational Weight Gain Increase the Risk for Childhood Asthma and Wheeze: An Updated Meta-Analysis

Background: Mounting evidence suggests that childhood asthma is closely associated with maternal weight before pregnancy and gestational weight gain (GWG), yet the results are not often reproducible. Objectives: We conducted a comprehensive meta-analysis, aiming to evaluate the association of pre-pregnancy maternal obesity or overweight and high GWG with the risk for childhood asthma and wheeze. Methods: Literature search, quality assessment, and data extraction were completed independently and in duplicate. Effect-size estimates are expressed as odds ratio (OR) with 95% confidence interval (CI). Results: Twenty-two observational studies involving 145,574 mother-child pairs were meta-analyzed. In overall analyses, maternal obesity or overweight in pre-pregnancy significantly increased the risk of both childhood asthma and wheeze (adjusted OR: 1.41 and 1.13, 95% CI: 1.26-1.59 and 1.07-1.20, both p < 0.001). Per 1 kg/m² increment in maternal body mass index was associated with a significantly increased risk of childhood asthma and wheeze (adjusted OR: 1.03, 95% CI: 1.02-1.03, p < 0.001). Compared with normal GWG, very high GWG (adjusted OR: 1.24, 95% CI: 1.04-1.47, p: 0.018), moderate high GWG (adjusted OR: 1.12, 95% CI: 1.04-1.21, p: 0.004), and very low GWG (adjusted OR: 1.26, 95% CI: 1.08-1.47, p: 0.004) increased the risk of childhood asthma and wheeze. There was a low probability of publication bias. Conclusions: Our findings indicate that both pre-pregnancy maternal obesity or overweight and very to moderate high or low GWG render their offspring susceptible to a significantly increased risk of having childhood asthma and wheeze.

Early life influences on child weight outcomes in the Study to Explore Early Development

We examined associations between child body mass index at 2-5 years and maternal pre-pregnancy body mass index, gestational weight gain, and rapid weight gain during infancy in children with autism spectrum disorder, developmental delays, or population controls. The Study to Explore Early Development is a multi-site case-control study of children, aged 2-5 years, classified as autism spectrum disorder ( n = 668), developmental delays ( n = 914), or population controls ( n = 884). Maternal gestational weight gain was compared to the Institute of Medicine recommendations. Rapid weight gain was a change in weight-for-age z-scores from birth to 6 months > 0.67 standard deviations. After adjusting for case status, mothers with pre-pregnancy overweight/obesity were 2.38 times (95% confidence interval: 1.96-2.90) more likely, and mothers who exceeded gestational weight gain recommendations were 1.48 times (95% confidence interval: 1.17-1.87) more likely, to have an overweight/obese child than other mothers ( P < 0.001). Children with autism spectrum disorder showed the highest frequency of rapid weight gain (44%) and were 3.47 times (95% confidence interval: 1.85-6.51) more likely to be overweight/obese as children with autism spectrum disorder without rapid weight gain ( P < 0.001). Helping mothers achieve a healthy pre-pregnancy body mass index and gestational weight gain represent important targets for all children. Healthy infant growth patterns carry special importance for children at increased risk for an autism spectrum disorder diagnosis.

Gut Microbiota Composition in Mid-Pregnancy Is Associated with Gestational Weight Gain but Not Prepregnancy Body Mass Index

Background: Pregnancy is a time of numerous hormonal, metabolic, and immunological changes for both the mother and the fetus. Furthermore, maternal gut microbiota composition (GMC) is altered during pregnancy. One major factor affecting GMC in pregnant and nonpregnant populations is obesity. The aim was to analyze associations between maternal overweight/obesity, as well as gestational weight gain (GWG) and GMC. Moreover, the modifying effect of depression and anxiety symptom scores on weight and GMC were investigated.

Methods: Study included 46 women from the FinnBrain Birth Cohort study, of which 36 were normal weight, and 11 overweight or obese according to their prepregnancy body mass index (BMI). Stool samples were collected in gestational week 24, and the GMC was sequenced with Illumina MiSeq approach. Hierarchical clustering was executed to illuminate group formation according to the GMC. The population was divided according to Firmicutes and Bacteroidetes dominance. Symptoms of depression, general anxiety, and pregnancy-related anxiety were measured by using standardized questionnaires.

Results: Excessive GWG was associated with distinct GMC in mid-pregnancy as measured by hierarchical clustering and grouping according to Firmicutes or Bacteroidetes dominance, with Bacteroidetes being prominent and Firmicutes being less prominent in the GMC among those with increased GWG. Reduced alpha diversity was observed among the Bacteroidetes-dominated subjects. There were no zero-order effects between the abundances of bacterial genera or phyla, alpha or beta diversity, and prepregnancy BMI or GWG.

Conclusion:Bacteroidetes-dominated GMC in mid-pregnancy is associated with increased GWG and reduced alpha diversity.

Risk factors for asthma occurrence in children with early-onset atopic dermatitis: An 8-year follow-up study

BACKGROUND

Children with early-onset atopic dermatitis (AD) are at substantial risk of developing asthma later in life, and identifying the critical window of detrimental exposure is advantageous for implementing preventive actions. The aim of this study was to evaluate the role of exposure to environmental modifiers during pregnancy and early childhood in asthma occurrence in an infantile AD cohort.

METHODS

Eligible study participants were selected from the Taiwan Birth Cohort Study, which enrolled 24 200 newborns in 2005. We enrolled those cases who had been diagnosed as having AD before 3 years of age and followed them up till age 8. We excluded those ever diagnosed with asthma before AD onset. The dependent variable was defined in terms of whether the participant was diagnosed as having asthma before 8 years of age. We applied logistic regression models to evaluate the risks of exposure to different determinants in asthma occurrence.

RESULTS

A total of 1549 children with AD had completed the 8-year follow-up, and 334 (21.6%) of them had asthma. The results revealed that male sex, lower birth order, maternal asthma history, maternal obesity before pregnancy, and environmental tobacco smoke exposure before 3 years of age were significant risk factors for further development of asthma. Furthermore, food allergy during early life, lower respiratory tract infection, and longer durations of symptomatic AD influenced asthma development later in life.

CONCLUSIONS

The findings confirmed the critical determinants for asthma occurrence in infantile AD, which may enable a more personalized approach to the prevention of asthma.

Maternal Obesity, Gestational Weight Gain, and Asthma in Offspring

INTRODUCTION

Obesity is common among women of childbearing age; intrauterine exposure to maternal obesity or gestational weight gain may influence the development of asthma in early childhood. We examined the relationships of maternal obesity and gestational weight gain with asthma in offspring.

METHODS

We used data from the Early Childhood Longitudinal Study-Birth Cohort, which has a nationally representative sample of children followed from birth in 2001 through age 4 (n = 6,450). Asthma was based on parental report of a medical professional's diagnosis. We used generalized estimating equation binomial models to compute adjusted odds ratios (ORs) of childhood asthma with maternal obesity and 4 measures of gestational weight gain.

RESULTS

Compared with children of normal-weight mothers, children of obese mothers had increased risk of asthma (adjusted OR, 1.63; 95% confidence interval [CI], 1.26-2.12) by age 4, and children born to overweight mothers had similar risk (adjusted OR, 1.25; 95% CI, 0.99-1.59). Extreme-low weight gain (<5 kg) and extreme-high weight gain (≥25 kg) were associated with increased risk of asthma; however, the following measures were not significant predictors of asthma: meeting gestational weight gain recommendations of the Institute of Medicine, total gestational weight gain, and weekly rate of weight gain in the second and third trimesters.

CONCLUSION

Extreme-low or extreme-high gestational weight gain and maternal obesity are risk factors for early childhood asthma, further evidence of the long-term impact of intrauterine exposure on children and the need to target preconception care to improve child health indicators.

Maternal body mass index: Relation with infant respiratory symptoms and infections

BACKGROUND

Maternal obesity is increasingly prevalent in many westernized countries. Many studies report associations between maternal obesity and childhood wheeze or asthma but few have considered maternal obesity in relation to respiratory infections or symptoms other than wheeze during infancy. This study assesses the relationship between maternal BMI and reported wheeze, cough and respiratory infections during the first year of life.

METHODS

In 2799 mother-child pairs, we examined the relations between maternal pre-pregnancy BMI and pregnancy weight gain and reported offspring wheeze, prolonged cough, lower respiratory tract infection, croup, and ear infection before age 1 year, along with reported diarrhea or vomiting. Maternally reported paternal BMI was included in the models as a proxy for unmeasured confounding by shared familial factors.

RESULTS

Higher maternal BMI was associated with increased risks of offspring wheeze, prolonged cough and lower respiratory tract infection (relative risks (95%CI) per 5 kg/m² 1.09 (1.05-1.13), 1.09 (1.03-1.14), and 1.13 (1.07-1.20), respectively). These associations remained after adjusting for maternally reported paternal BMI. No associations were found with croup, ear infection, or diarrhea or vomiting. Pregnancy weight gain was not associated with any of the offspring symptoms or illnesses.

DISCUSSION

Higher maternal BMI is associated with increased risk of wheeze, cough, and maternally reported lower respiratory tract infection in infancy. These associations were independent of maternally reported paternal BMI. These observations might be explained by intrauterine effects of maternal obesity upon respiratory or immune development.

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.

Association between perfluoroalkyl substance exposure and asthma and allergic disease in children as modified by MMR vaccination

Perfluoroalkyl substances (PFASs) are highly persistent chemicals that might be associated with asthma and allergy, but the associations remain unclear. Therefore, this study examined whether pre- and postnatal PFAS exposure was associated with childhood asthma and allergy. Measles, mumps, and rubella (MMR) vaccination in early life may have a protective effect against asthma and allergy, and MMR vaccination is therefore taken into account when evaluating these associations. In a cohort of Faroese children whose mothers were recruited during pregnancy, serum concentrations of five PFASs - Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) - were measured at three timepoints (maternal serum in pregnancy week 34-36 and child serum at ages 5 and 13 years) and their association with immunoglobulin E (IgE) (cord blood and at age 7 years) and asthma/allergic diseases (questionnaires at ages 5 and 13 years and skin prick test at age 13 years) was determined. A total of 559 children were included in the analyses. Interactions with MMR vaccination were evaluated. Among 22 MMR-unvaccinated children, higher levels of the five PFASs at age 5 years were associated with increased odds of asthma at ages 5 and 13. The associations were reversed among MMR-vaccinated children. Prenatal PFAS exposure was not associated with childhood asthma or allergic diseases regardless of MMR vaccination status. In conclusion, PFAS exposure at age 5 was associated with increased risk of asthma among a small subgroup of MMR-unvaccinated children but not among MMR-vaccinated children. While PFAS exposure may impact immune system functions, this study suggests that MMR vaccination might be a potential effect-modifier.

Influence of maternal obesity on the long-term health of offspring

In addition to immediate implications for pregnancy complications, increasing evidence implicates maternal obesity as a major determinant of offspring health during childhood and later adult life. Observational studies provide evidence for effects of maternal obesity on her offspring's risks of obesity, coronary heart disease, stroke, type 2 diabetes, and asthma. Maternal obesity could also lead to poorer cognitive performance and increased risk of neurodevelopmental disorders, including cerebral palsy. Preliminary evidence suggests potential implications for immune and infectious-disease-related outcomes. Insights from experimental studies support causal effects of maternal obesity on offspring outcomes, which are mediated at least partly through changes in epigenetic processes, such as alterations in DNA methylation, and perhaps through alterations in the gut microbiome. Although the offspring of obese women who lose weight before pregnancy have a reduced risk of obesity, few controlled intervention studies have been done in which maternal obesity is reversed and the consequences for offspring have been examined. Because the long-term effects of maternal obesity could have profound public health implications, there is an urgent need for studies on causality, underlying mechanisms, and effective interventions to reverse the epidemic of obesity in women of childbearing age and to mitigate consequences for offspring.

Maternal body mass index before pregnancy is associated with increased bronchodilator dispensing in early childhood: A cross-sectional study

RATIONALE

Maternal prepregnancy obesity has been associated with early wheeze and childhood asthma in their offspring. Some of these studies have been in minority, urban, and disadvantaged populations using parental recall and questionnaires. The association of maternal prepregnancy obesity with bronchodilator dispensing to their offspring, in a primarily insured, non-urban, White population in the United States is unknown.

OBJECTIVES AND METHODS

We conducted a retrospective cohort study using pharmacy dispensing data from the electronic medical records of a large United States health maintenance organization to examine the relationship between maternal prepregnancy body mass index (BMI) and inhaled bronchodilator dispensing in the offspring to 4 years of age. We included infants ≥37 weeks' gestation with birth weight ≥2.5 kg which yielded 6,194 mother-baby pairs. Maternal prepregnancy BMI was categorized as underweight (<18.5 kg/m(2) ), normal (18.5-24.9 kg/m(2) ), overweight (25-29.9 kg/m(2) ), or obese (≥30 kg/m(2) ).

RESULTS

In the entire cohort, 27.6% of the offspring received a bronchodilator dispensing. This ranged from 19.2% in the offspring of underweight mothers to 31.3% of those born to obese mothers. In the fully adjusted model using normal BMI as the referent, children of obese mothers had a 22% higher rate of bronchodilator dispensing (adjusted OR = 1.22; 95%CI 1.05-1.41; P = 0.008).

CONCLUSIONS

In this insured, non-urban, White population, maternal prepregnancy obesity was associated with bronchodilator dispensing in the offspring in early life. These results extend previous data and reaffirm the potential widespread public health impact that prepregnancy obesity may have on subsequent childhood respiratory health. Pediatr Pulmonol. 2016;51:803-811. © 2016 Wiley Periodicals, Inc.

Household Food Insecurity is Associated with Childhood Asthma

BACKGROUND

In 2013, 20% of U.S. households with children experienced food insecurity. Asthma afflicts over 7 million children; prevalence has steadily increased while incidence peaks in young children. Asthma and food insecurity share the determinants of poverty and race that are associated with weight, yet limited research on the relation between food insecurity and asthma exists.

OBJECTIVE

The objective of this study was to determine the association between food insecurity and asthma in a diverse sample of children.

METHODS

Cross-sectional data from grade 3 of the Early Childhood Longitudinal Study-Kindergarten Cohort were analyzed (n = 11,099). Food security based on the USDA module and asthma diagnosis were reported by parents; anthropometric factors were measured. Multivariate logistic regression models of food security and asthma were analyzed overall and by race/ethnicity.

RESULTS

Children in food-insecure households had a 4% higher adjusted odds of asthma (95% CI: 1.02, 1.06). Adjusted odds of asthma were also higher by 70% for males (95% CI: 1.69, 1.71), 53% for non-Hispanic black (NHB) children (95% CI: 1.51, 1.54), 20% for Hispanic children (95% CI: 1.19, 1.21), 38% for overweight children (95% CI: 1.36, 1.39), 67% for obese children (95% CI: 1.65, 1.68), 23% for low-birth weight children (95% CI: 1.21, 1.24), 24% if mothers had a high school diploma (95% CI: 1.23, 1.26), and 33% if mothers had some college education (95% CI: 1.32, 1.35). High-birth weight children (OR: 0.84; 95% CI: 0.83, 0.85) and those with foreign-born mothers (OR: 0.52; 95% CI: 0.51, 0.53) had lower odds of asthma. Being food-insecure remained positively associated with asthma in non-Hispanic whites and Hispanics but was inversely associated with odds among NHBs. Odds of asthma doubled (OR: 2.00; 95% CI: 1.97, 2.03) for all children in households that were both food-insecure and poor; this relation remained positive in race/ethnicity-specific models.

CONCLUSIONS

Food insecurity is positively associated with asthma in U.S. third graders, and household poverty strengthens the association.

A Study on Mediation by Offspring BMI in the Association between Maternal Obesity and Child Respiratory Outcomes in the Amsterdam Born and Their Development Study Cohort

BACKGROUND

A causal relationship between maternal obesity and offspring asthma is hypothesized to begin during early development, but no underlying mechanism for the found association is identified. We quantitatively examined mediation by offspring body mass index (BMI) in the association of maternal pre-pregnancy BMI on risk of asthma and wheezing during the first 7-8 years of life in a large Amsterdam born birth cohort.

METHODS

For 3185 mother-child pairs, mothers reported maternal pre-pregnancy BMI and offspring outcomes "ever being diagnosed with asthma" and "wheezing in the past 12 months" on questionnaires. We measured offspring height and weight at age 5-6 years. We performed a multivariate log linear regression comparing outcomes in offspring of mothers with different BMI categories. For each category we quantified and tested mediation by offspring BMI and also investigated interaction by parental asthma.

RESULTS

At the age of 7-8 years, 8% of the offspring ever had asthma and 7% had current wheezing. Maternal pre-pregnancy obesity was associated with higher risks of asthma (adjusted RR 2.32 (95% CI: 1.49-3.61) and wheezing (adjusted RR 2.16 (95% CI: 1.28-3.64). Offspring BMI was a mediator in the association between maternal BMI and offspring wheezing, but not for asthma. There was no interaction by parental asthma.

CONCLUSIONS

Maternal pre-pregnancy obesity was associated with higher risks of offspring asthma and wheezing. The association between maternal obesity and offspring wheezing was both direct and indirect (mediated) through the child's own BMI.

Maternal obesity and immune dysregulation in mother and infant: A review of the evidence

Obesity is a worldwide public health epidemic. Increasing numbers of reproductive-age women enter pregnancy overweight or obese and there is now convincing data that this adverse in utero environment impacts both fetal and lifelong development. Epidemiologic evidence has shown a simultaneous increase in obesity and asthma rates in developed countries and maternal obesity is a risk factor for infant asthma and wheeze. Here we review the state of research linking maternal obesity and immunomodulation in both mother and infant, with specific attention to the relationship between maternal obesity and offspring asthma. We will also propose several different mechanisms by which maternal obesity may predispose offspring to this chronic condition and briefly summarize interventions that have been trialed to limit this association.

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

BACKGROUND

Evidence on the effect of maternal complications in pregnancy on wheezing in offspring is still insufficient.

METHODS

A pooled analysis was performed on individual participant data from fourteen European birth cohorts to assess the relationship between several maternal pregnancy complications and wheezing symptoms in the offspring. Exposures of interest included hypertension and preeclampsia, diabetes, as well as pre-pregnancy overweight (body mass index between 25 and 29.9) and obesity (body mass index ≥ 30) compared with normal weight (body mass index between 18.5 and 24.9). Outcomes included both ever and recurrent wheezing from birth up to 12-24 months of age. Cohort-specific crude and adjusted risk ratios (RR) were calculated using log-binomial regression models and then pooled using a random effects model.

RESULTS

The study included 85509 subjects. Cohort-specific prevalence of ever wheezing varied from 20.0% to 47.3%, and of recurrent wheezing from 3.0% to 14.3%. Adjusted pooled RR for ever and recurrent wheezing were: 1.02 (95% CI: 0.98-1.06) and 1.20 (95% CI: 0.98-1.47) for hypertensive disorders; 1.09 (95% CI: 1.01-1.18) and 1.23 (95% CI: 1.07-1.43) for preeclampsia; 1.04 (95% CI: 0.97-1.13) and 1.24 (95% CI: 0.86-1.79) for diabetes; 1.08 (95% CI: 1.05-1.11) and 1.19 (95% CI: 1.12-1.26) for overweight; 1.12 (95% CI: 1.08-1.17) and 1.16 (95% CI: 0.97-1.39) for obesity. No heterogeneity was found in RR estimates among the cohorts, except for diabetes and recurrent wheezing (P=0.027).

CONCLUSIONS

Preeclampsia, maternal pre-pregnancy overweight and obesity are associated with an increase risk of wheezing in the offspring.

Maternal obesity in pregnancy, gestational weight gain, and risk of childhood asthma

BACKGROUND AND OBJECTIVE

Environmental or lifestyle exposures in utero may influence the development of childhood asthma. In this meta-analysis, we aimed to assess whether maternal obesity in pregnancy (MOP) or increased maternal gestational weight gain (GWG) increased the risk of asthma in offspring.

METHODS

We included all observational studies published until October 2013 in PubMed, Embase, CINAHL, Scopus, The Cochrane Database, and Ovid. Random effects models with inverse variance weights were used to calculate pooled risk estimates.

RESULTS

Fourteen studies were included (N = 108 321 mother-child pairs). Twelve studies reported maternal obesity, and 5 reported GWG. Age of children was 14 months to 16 years. MOP was associated with higher odds of asthma or wheeze ever (OR = 1.31; 95% confidence interval [CI], 1.16-1.49) or current (OR = 1.21; 95% CI, 1.07-1.37); each 1-kg/m(2) increase in maternal BMI was associated with a 2% to 3% increase in the odds of childhood asthma. High GWG was associated with higher odds of asthma or wheeze ever (OR = 1.16; 95% CI, 1.001-1.34). Maternal underweight and low GWG were not associated with childhood asthma or wheeze. Meta-regression showed a negative association of borderline significance for maternal asthma history (P = .07). The significant heterogeneity among existing studies indicates a need for standardized approaches to future studies on the topic.

CONCLUSIONS

MOP and high GWG are associated with an elevated risk of childhood asthma; this finding may be particularly significant for mothers without asthma history. Prospective randomized trials of maternal weight management are needed.

Increased maternal BMI is associated with infant wheezing in early life: a prospective cohort study

Rates of obesity are increasing in women of child bearing age with negative impacts on maternal and offspring health. Emerging evidence suggests in utero origins of respiratory health in offspring of obese mothers but mechanisms are unknown. Changes in maternal cortisol levels are one potential factor as cortisol levels are altered in obesity and cortisol is separately implicated in development of offspring wheeze. We aimed to assess whether increased pre-pregnancy maternal body mass index (BMI) was associated with offspring early life wheezing, and whether this was mediated by altered cortisol levels in the mother. In a prospective community-based cohort (Amsterdam Born Children and their Development cohort), women completed questionnaires during pregnancy and at 3-5 months post-delivery regarding self-history of asthma and atopy, and of wheezing of their offspring (n=4860). Pre-pregnancy BMI was recorded and serum total cortisol levels were measured in a subset of women (n=2227) at their first antenatal visit. A total of 20.2% (n=984) women were overweight or obese and 10.3% reported wheezing in their offspring. Maternal BMI was associated with offspring wheezing (1 unit (kg/m2) increase, OR: 1.03; 95% CI: 1.00-1.05), after correction for confounders. Although maternal cortisol levels were lower in overweight mothers and those with a history of asthma, maternal cortisol levels did not mediate the increased offspring wheezing. Pre-pregnancy BMI impacts on baby wheezing, which is not mediated by lower cortisol levels. As the prevalence of obesity in women of child-bearing age is increasing, further studies are needed to investigate modifiable maternal factors to avoid risk of wheezing in young children.

Subcutaneous body fat in pregnant New Zealand women: association with wheeze in their infants at 18 months

To investigate the association of subcutaneous body fat levels in pregnant women with wheezing in their 18 month old infants. A prospective study of European and Polynesian volunteers (n = 369) recruited from northern New Zealand were visited in months 4 and 7 of pregnancy when height, weight, and triceps, biceps and costal skinfolds were measured, and questionnaires determining personal details administered; and again visited 18 months after birth when infants were measured and questions on infant feeding and wheeze administered. At 18 months 32 % of infants had wheezed in the past 12 months. Increased wheeze was associated with maternal asthma, eczema or allergy (p = 0.001); receiving family welfare payments (p = 0.010); and being Polynesian (p = 0.021); while exclusive breastfeeding to 2 months (p = 0.045) was associated with decreased wheeze. Individual month 4 and month 7 mean triceps, biceps and costal skinfolds were all greater in mothers of wheezers compared to nonwheezers, biceps and costal skinfolds significantly so (p = 0.002, p = 0.005 at month 7). The sum of these skinfolds at month 4, at month 7, and the difference between these sums, were all significantly associated with increased risk of infant wheeze at 18 months when considered alone (p = 0.037, p = 0.001 and p = 0.015) or in combination. Prevalence of infant wheeze was 22.7 % for mothers with lower quartile month 7 skinfolds, compared to 45.0 % for mothers with upper quartile. After adjusting for significant covariates the difference in skinfolds had the strongest association (p = 0.003) followed by sum at month 4 (p = 0.074 or 0.003 depending on whether Polynesian ethnicity was included in the model). The sum of skinfolds declined between month 4 and month 7 in 34 % of women. Prevalence of wheeze was 19.2 % where the difference in mothers' skinfolds between month 4 and month 7 decreased by 10 mm or more and 41.7 % where the difference increased by 10 mm or more. Mean month 4 weights, BMI and sum of skinfolds were below average in the latter group. As the sum of month 4 or month 7 maternal skinfolds increased the prevalence of infant wheeze increased. In addition as the change in skinfolds between month 4 and month 7 became more positive the prevalence of infant wheeze increased. This study suggests for the first time that changes in subcutaneous fat during pregnancy are associated with prevalence of infant wheeze.

Perinatal factors in neonatal and pediatric lung diseases

Wheezing and asthma are significant clinical problems for infants and young children, particularly following premature birth. Recurrent wheezing in infants can progress to persistent asthma. As in adults, altered airway structure (remodeling) and function (increased bronchoconstriction) are also important in neonatal and pediatric airway diseases. Accumulating evidence suggests that airway disease in children is influenced by perinatal factors including perturbations in normal fetal lung development, postnatal interventions in the intensive care unit (ICU) and environmental and other insults in the neonatal period. Here, in addition to genetics, maternal health, environmental processes, innate immunity and impaired lung development/function can all influence pathogenesis of airway disease in children. We summarize current understanding of how prenatal and postnatal factors can contribute to development of airway diseases in neonates and children. Understanding these mechanisms will help identify and develop novel therapies for childhood airway diseases.

Maternal pre-gravid obesity and early childhood respiratory hospitalization: a population-based case-control study

Inflammation in utero is linked to childhood respiratory and infectious complications. Obesity is an increasingly common chronic inflammatory state, yet little is known about its role in childhood respiratory illness. We sought to examine the association between maternal pre-gravid BMI and early childhood respiratory hospitalization. We conducted a population-based case-control study using the Washington State Comprehensive Hospital Abstract Reporting System and linked birth certificate data. Cases were children age 0-5 years, born in Washington state, with a respiratory hospitalization between 2003 and 2008. We identified 15,318 cases, frequency matching each case to two controls by birth year (total 31,060 controls). We used logistic regression to estimate the risk (approximated by odds ratios) of early childhood respiratory hospitalization according to maternal pre-gravid body mass index (BMI) category (underweight, normal, overweight, obese), after adjustment for maternal and infant characteristics. An elevated maternal pre-gravid BMI was associated with increased risk of childhood respiratory hospitalization, with an adjusted odds ratio OR [95 % CI] = 1.08 [1.03-1.14] for overweight mothers (BMI 25-29.9 kg/m(2)), and OR = 1.29 [1.22-1.36] for obese mothers (BMI ≥ 30 kg/m(2)). An elevated maternal pre-gravid BMI was associated with higher risk of early childhood respiratory hospitalization. Childhood respiratory illness may be an important complication of excess maternal weight that should be shared with expectant mothers.

Disrupted prenatal maternal cortisol, maternal obesity, and childhood wheeze. Insights into prenatal programming

RATIONALE

Exploring prenatal factors influencing childhood wheeze may inform programming mechanisms.

OBJECTIVES

We examined associations among prenatal maternal cortisol profiles, maternal obesity, and repeated wheeze up to age 2 years (n = 261).

METHODS

Salivary cortisol was collected five times per day over 3 days at 29.0 ± 4.9 weeks gestation. Mothers were categorized as obese (body mass index ≥ 30 kg/m(2)) versus nonobese (body mass index < 30 kg/m(2)). Using logistic regression, we examined the influence of log-transformed cortisol metrics (level at each time point, morning rise, diurnal and afternoon slopes) and obesity on wheeze adjusting for covariates. Linear mixed models were implemented to examine associations between cortisol trajectories and wheezing. Interactions between maternal cortisol and obesity were considered.

MEASUREMENTS AND MAIN RESULTS

Mothers were primarily minority (56.5% Hispanic, 24.1% African American), 61% had less than or equal to 12 years of education, 34% were obese, and 8.4% of children had repeated wheeze. An interquartile range increase in mean log cortisol at bedtime (odds ratio, 2.2; 95% confidence interval, 1.09-4.09) and maternal obesity (odds ratio, 3.43; 95% confidence interval, 1.26-9.35) were independently associated with wheeze. Linear mixed models revealed an association between a flatter afternoon slope (slower decline in log cortisol per hour) and repeated wheeze in children of obese mothers (children with [-0.017 change] and without [-0.061 change] wheeze [P = 0.009 for time × wheeze interaction]), but not in children of nonobese mothers (with [-0.050 change] and without [-0.061 change] wheeze [P = 0.51]).

CONCLUSIONS

Maternal prenatal cortisol disruption and obesity were independently associated with children's wheeze. Obese women with adverse cortisol profiles were most likely to have children with repeated wheeze.

Impact of maternal obesity on inhaled corticosteroid use in childhood: a registry based analysis of first born children and a sibling pair analysis

BACKGROUND

It has been proposed that maternal obesity during pregnancy may increase the risk that the child develops allergic disease and asthma, although the mechanisms underpinning this relationship are currently unclear. We sought to assess if this association may be due to confounding by genetic or environmental risk factors that are common to maternal obesity and childhood asthma, using a sibling pair analysis.

METHODS

The study population comprised a Swedish national cohort of term children born between 1992 and 2008 to native Swedish parents. Maternal body mass index (BMI) was measured at 8-10 weeks gestation. Unconditional logistic regression models were used to determine if maternal obesity was associated with increased risk of inhaled corticosteroid (ICS) in 431,718 first-born children, while adjusting for potential confounders. An age-matched discordant sib-pair analysis was performed, taking into account shared genetic and environmental risk factors.

RESULTS

Maternal over-weight and obesity were associated with increased risk that the child would require ICS (for BMI≥35 kg/m(2), aOR = 1.30, 95%CI = 1.10-1.52 compared with normal weight mothers) in children aged 6-12 years. Similar effects were seen in younger children, but in children aged 13-16 years, maternal obesity (BMI≥30) was related to increased risk of ICS use in girls (aOR = 1.28, 95%CI = 1.07-1.53) but not boys (OR = 1.05, 95%CI = 0.87-1.26). The sib-pair analysis, which included 2,034 sib-pairs older than six years who were discordant for both ICS use and maternal BMI category, failed to find any evidence that increasing maternal weight was related to increased risk of ICS use.

CONCLUSION

Maternal obesity is associated with increased risk of childhood ICS use up to approximately 12 years of age, but only in girls after this age. These effects could not be confirmed in a sib pair analysis, suggesting either limited statistical power, or the effects of maternal BMI may be due to shared genetic or environmental risk factors.

Maternal pre-pregnancy body mass index and offspring temperament and behavior at 1 and 2 years of age

Recent research suggests that fetal exposure to increased maternal body mass index (BMI) during pregnancy may be associated with psychopathology later in life. When this link first emerges, and if it is due to intrauterine exposures or confounding variables is not known. We therefore assessed associations between maternal pre-pregnancy BMI and: (1) temperament at 1 year of age, and (2) Child Behavior Checklist internalizing and externalizing scales at age 2 in the 2900 mothers and infants enrolled in the Western Australian Pregnancy Study. Pre-pregnancy BMI was positively associated with externalizing scores (β = 0.131, 95 % CI 0.013-0.249) at age 2, even after adjustment for confounders, but not with internalizing scores or an increased risk of difficult temperament. These data suggest that fetal exposure to increased maternal BMI is associated with elevated levels of behavior problems as early as age 2, and that this may be linked to the intrauterine environment.

Association of maternal diabetes and child asthma

BACKGROUND

Perinatal programming is an emerging theory for the fetal origins of chronic disease. Maternal asthma and environmental tobacco smoke (ETS) are two of the best-known triggers for the perinatal programming of asthma, while the potential role of maternal diabetes has not been widely studied.

OBJECTIVE

To determine if maternal diabetes is associated with child asthma, and if so, whether it modifies the effects of ETS exposure and maternal asthma.

METHODS

We studied 3,574 Canadian children, aged 7-8 years, enrolled in a population-based birth cohort. Standardized questionnaires were completed by the children's parents, and data were analyzed by multivariable logistic regression.

RESULTS

Asthma was reported in 442 children (12.4%). Compared to those without asthma, asthmatic children were more likely to have mothers (P = 0.003), but not fathers (P = 0.89), with diabetes. Among children without maternal history of diabetes, the likelihood of child asthma was 1.4-fold higher in those exposed to ETS (adjusted odds ratio, 1.40; 95% confidence interval, 1.13-1.73), and 3.6-fold higher in those with maternal asthma (3.59; 2.71-4.76). Among children born to diabetic mothers, these risks were amplified to 5.7-fold (5.68; 1.18-27.37) and 11.3-fold (11.30; 2.26-56.38), respectively. In the absence of maternal asthma or ETS, maternal diabetes was not associated with child asthma (0.65, 0.16-2.56).

CONCLUSION

Our findings suggest that maternal diabetes may contribute to the perinatal programming of child asthma by amplifying the detrimental effects of ETS exposure and maternal asthma.

The relationship between maternal adiposity and infant weight gain, and childhood wheeze and atopy

BACKGROUND

Obesity and asthma have increased in westernised countries. Maternal obesity may increase childhood asthma risk. If this relation is causal, it may be mediated through factors associated with maternal adiposity, such as fetal development, pregnancy complications or infant adiposity. We investigated the relationships of maternal body mass index (BMI) and fat mass with childhood wheeze, and examined the influences of infant weight gain and childhood obesity.

METHODS

Maternal prepregnancy BMI and estimated fat mass (from skinfold thicknesses) were related to asthma, wheeze and atopy in 940 children. Transient or persistent/late wheeze was classified using questionnaire data collected at ages 6, 12, 24 and 36 months and 6 years. At 6 years, skin-prick testing was conducted and exhaled nitric oxide and spirometry measured. Infant adiposity gain was calculated from skinfold thickness at birth and 6 months.

RESULTS

Greater maternal BMI and fat mass were associated with increased childhood wheeze (relative risk (RR) 1.08 per 5 kg/m(2), p=0.006; RR 1.09 per 10 kg, p=0.003); these reflected associations with transient wheeze (RR 1.11, p=0.003; RR 1.13, p=0.002, respectively), but not with persistent wheeze or asthma. Infant adiposity gain was associated with persistent wheeze, but not significantly. Adjusting for infant adiposity gain or BMI at 3 or 6 years did not reduce the association between maternal adiposity and transient wheeze. Maternal adiposity was not associated with offspring atopy, exhaled nitric oxide, or spirometry.

DISCUSSION

Greater maternal adiposity is associated with transient wheeze but not asthma or atopy, suggesting effects upon airway structure/function but not allergic predisposition.

Maternal pre-pregnancy body mass index and internalizing and externalizing problems in offspring

OBJECTIVE

To determine if maternal pre-pregnancy body mass index (BMI) is associated with increased levels of internalizing and externalizing symptomatology in offspring throughout childhood and adolescence, and if these links persist after adjusting for the confounders of these associations.

METHOD

We examined links between maternal pre-pregnancy BMI and internalizing and externalizing symptoms in the offspring of 2785 members of the Western Australian Pregnancy (Raine) Cohort. Mothers rated these problems using the Child Behavior Checklist when their children were 5, 8, 10, 14, and 17 years of age. Growth curves were generated using multilevel linear regression to examine associations and to determine if changes in levels of these symptoms varied over time by maternal BMI.

RESULTS

Increased maternal pre-pregnancy BMI was associated with stably elevated levels of externalizing problems, and exhibited a statistically significant interaction with internalizing problems over time, indicating that youth born to mothers with higher maternal pre-pregnancy BMIs had less rapid decreases in internalizing scores as they got older. Significant positive associations between maternal pre-pregnancy BMI and elevated levels of internalizing problems emerged at age 8 and increased through 17. These findings persisted despite adjustment for confounders.

CONCLUSIONS

Exposure to elevated maternal pre-pregnancy BMI is associated with increased levels of internalizing and externalizing problems throughout childhood and adolescence. Further work is required to establish if these associations are causal. If elevated maternal pre-pregnancy BMI is causally linked to psychopathology in offspring, it could provide a potentially realizable target for the prevention of mental health problems in youth.

Obesity during pregnancy and fetal iron status: is Hepcidin the link?

OBJECTIVE

To ascertain the effect of obesity-related inflammation on maternal and fetal iron status. We hypothesized that obese (Ob) pregnant women would have increased inflammation, hepcidin levels, and that their infants would have impaired iron status compared with lean (Lc) controls.

STUDY DESIGN

Fifteen Ob and fifteen Lc women were recruited in their second trimester of pregnancy. Markers of iron status, inflammation and hepcidin were measured in maternal and cord blood. Student's t-test was used to compare Ob and Lc groups, and Pearson's correlation coefficients were determined between maternal and cord blood values.

RESULT

Maternal C-reactive protein (P<0.01) and hepcidin (P<0.01) were higher, and cord blood iron (P<0.01) was lower in the Ob group. Maternal body mass index (P<0.01) and hepcidin (P<0.05) were negatively correlated with cord blood iron status.

CONCLUSION

Maternal obesity is associated with impaired maternal-fetal iron transfer, potentially through hepcidin upregulation.

Asthma and pregnancy

Asthma is probably the most common serious medical disorder that may complicate pregnancy. A third of pregnant women with asthma will experience worsening of their symptoms, a third will see improvement of their symptoms and a third will see no change. The primary goal is to maintain optimal control of asthma for maternal health and well-being as well as fetal maturation. Vital patient education should cover the use of controller medication, avoidance of asthma triggers and early treatment of asthma exacerbations. Proper asthma management should ideally be started in the preconception period. Since smoking is probably the most modifiable risk factor of asthma, pregnant woman should avoid active and passive smoking. Acute asthma exacerbation during the first trimester is associated with an increased risk of congenital malformations. Poorly controlled asthma is associated with low birth weight, preeclampsia, and preterm birth. Medications used for asthma control in the non-pregnant population are generally the same in pregnancy with a few exceptions. Inhaled corticosteroids (ICS) are the preferred controller therapy. Budesonide is the preferred ICS. Long-acting B-agonists (LABA) are the preferred add-on therapy to medium to high dose ICS. Major triggers for asthma exacerbations during pregnancy are viral infections and ICS nonadherence.

Maternal prepregnancy obesity is an independent risk factor for frequent wheezing in infants by age 14 months

BACKGROUND

Maternal prepregnancy obesity has been linked to the offspring's risk for subsequent asthma. We determined whether maternal obesity is associated with increased risk of wheezing phenotypes early in life.

METHODS

We used data on 1107 mother-child pairs from two birth cohorts from the INMA-INfancia y Medio Ambiente project. Maternal height was measured and prepregnancy weight self-reported at enrolment (on average at 13.7 ± 2 weeks of gestation). Maternal prepregnancy body mass index was categorised as underweight, normal, overweight and obese according to WHO recommendations. Information on child's wheezing was obtained through questionnaires up to the age of 14 (± 1) months. Wheezing was classified as infrequent (<4 reported wheezing episodes) or frequent (≥ 4 episodes). Weight and length of infants were measured by trained study staff at 14.6 (± 1) months of age and weight-for-length z-scores computed.

RESULTS

Although maternal obesity did not increase the risk of the child to have any or infrequent wheezing, children of obese mothers were more likely to have frequent wheezing than children of normal-weight mothers (11.8% vs. 3.8%; P = 0.002). In fully adjusted multinomial logistic regression models, including infants' weight-for-length z-scores and other covariates, maternal prepregnancy obesity was associated with increased risk of frequent [adjusted relative risk (RR) 4.18, 95% confidence interval (CI) 1.55, 11.3] but not infrequent (RR 1.05 [95% CI 0.55, 2.01]) wheezing in their children.

CONCLUSIONS

Maternal prepregnancy obesity is independently associated with an increased risk of frequent wheezing in the infant by the age of 14 months. These findings add evidence on the potential effects of in utero exposures on asthma-related phenotypes.

Asthma in children born after infertility treatment: findings from the UK Millennium Cohort Study

STUDY QUESTION

Is asthma more common in children born after subfertility and assisted reproduction technologies (ART)?

SUMMARY ANSWER

Yes. Asthma, wheezing in the last year and anti-asthmatic medication were all more common in children born after a prolonged time to conception (TTC). This was driven specifically by an increase in children born after ART.

WHAT IS KNOWN ALREADY

Few studies have investigated any association between ART and asthma in subsequent children, and findings to date have been mixed. A large registry-based study found an increase in asthma medication in ART children but suggests underlying infertility is the putative risk factor. Little is known about asthma in children after unplanned or mistimed conceptions.

STUDY DESIGN, SIZE, DURATION

The Millennium Cohort Study is a UK-wide, prospective study of 18 818 children recruited at 9 months of age. Follow-up is ongoing. This study analyses data from follow-up surveys at 5 and 7 years of age (response rates of 79 and 70%, respectively).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Singleton children whose natural mothers provided follow-up data were included. Mothers reported whether their pregnancy was planned; planners provided TTC and details of any ART. The population was divided into 'unplanned' (unplanned and unhappy), 'mistimed' (unplanned but happy), 'planned' (planned, TTC < 12 months), 'untreated subfertile' (planned, TTC >12 months), 'ovulation induced' (received clomiphene citrate) and 'ART' (IVF or ICSI). The primary analysis used the planned children as the comparison group; secondary analysis compared the treatment groups to the children born to untreated subfertile parents. Outcomes were parent report of asthma and wheezing at 5 and 7 years, derived from validated questions in the International Study of Asthma and Allergies in Childhood, plus use of anti-asthmatic medications. A total of 13 041 (72%) children with full data on asthma and confounders were included at 5 years of age, and 11 585 (64%) at 7 years.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with planned children, those born to subfertile parents were significantly more likely to experience asthma, wheezing and to be taking anti-asthmatics at 5 years of age [adjusted odds ratio (OR): 1.39 (95% confidence interval (CI): 1.07, 1.80), OR: 1.27 (1.00, 1.63) and OR: 1.90 (1.32,2.74), respectively]. This association was mainly related to an increase among children born after ART (adjusted OR: 2.65 (1.48, 4.76), OR: 1.97, (1.10, 3.53) and OR: 4.67 (2.20, 9.94) for asthma, wheezing and taking anti-asthmatics, respectively). The association was also present, though reduced, at the age of 7 years.

LIMITATIONS, REASONS FOR CAUTION

The number of singletons born after ART was relatively small (n = 104), and as such the findings should be interpreted with caution. However, data on a wide range of possible confounding and mediating factors were available and analysed. The data were weighted for non-response to minimize selection bias.

WIDER IMPLICATIONS OF THE FINDINGS

The findings add to the growing body of evidence suggesting an association between subfertility, ART and asthma in children. Further work is needed to establish causality and elucidate the underlying mechanism. These findings are generalizable to singletons only, and further work on multiples is needed.

Maternal obesity, gestational weight gain, and risk of asthma and atopic disease in offspring: a study within the Danish National Birth Cohort

BACKGROUND

High pre-pregnancy body mass index (BMI) and excessive gestational weight gain (GWG) are suggested to influence risk of asthma and atopic disease in offspring.

OBJECTIVE

We examined the effect of BMI and GWG on risk of asthma, wheezing, atopic eczema (AE), and hay fever in children during the first 7 years of life.

METHODS

This was a cohort study of 38,874 mother-child pairs from the Danish National Birth Cohort (enrollment 1996-2002) with information from the 16th week of pregnancy and at age 6 months, 18 months, and 7 years of the child. Odds ratios (ORs) with 95% CIs were calculated by logistic regression with adjustment for potential confounders.

RESULTS

During the first 7 years of life, 10.4% of children developed doctor-diagnosed asthma, 25.8% AE, and 4.6% hay fever. Maternal BMI and to a lesser extent GWG were associated with doctor-diagnosed asthma ever. In particular, BMI≥35 (adjusted OR, 1.87; 95% CI, 0.95-3.68) and GWG≥25 kg (adjusted OR, 1.97; 95% CI, 1.38-2.83) were associated with current severe asthma at age 7 years. Maternal BMI was also associated with wheezing in offspring, with the strongest association observed between BMI≥35 and late-onset wheezing (adjusted OR, 1.87; 95% CI, 1.28-2.73). Maternal BMI and GWG were not associated with AE or hay fever.

CONCLUSIONS

Maternal obesity during pregnancy was associated with increased risk of asthma and wheezing in offspring but not with AE and hay fever, suggesting that pathways may be nonallergic.

Prenatal exposure to acid-suppressive drugs and the risk of childhood asthma: a population-based Danish cohort study

BACKGROUND

Proton pump inhibitors (PPIs) may activate the immune system and cause asthma.

AIM

To investigate the association of prenatal exposure to PPIs and histamine 2-receptor antagonists (H2RAs) with risk of asthma.

METHODS

In this cohort study, 197,060 singletons born between 1996 and 2008 in northern Denmark were followed until the end of 2009. Data were obtained through Danish medical registries. Asthma in offspring was defined as at least two prescriptions of both a β-agonist and an inhaled glucocorticoid and/or a hospital diagnosis of asthma during the follow-up. Cox proportional-hazard regression was used to compute incidence rate ratios, adjusting for covariates.

RESULTS

A total of 2238 (1.1%) children were prenatally exposed to PPIs and 24,506 (12.4%) children developed asthma during follow-up (median follow-up = 6.8 years). The adjusted IRR (aIRR) of asthma associated with prenatal exposure to PPIs was 1.41 (95% confidence interval (CI): 1.27-1.56), compared with those unexposed. The association did not vary by trimester of exposure, and prenatal exposure to H2RAs was associated with similar increase in risk. The aIRR for maternal PPI and H2RA use in the year after, but not during pregnancy was 1.32 (95% CI: 1.20-1.46) and 1.13 (0.93-1.36), respectively, compared with non-use during and in the year after pregnancy.

CONCLUSIONS

Prenatal exposure to both PPIs and H2RAs was associated with an increased risk of asthma in our study. Because the observed association is not drug specific and also observed for maternal postnatal use it may be explained by a 'class effect' or maternal underlying condition.

Fetal origins of asthma

There is convincing evidence that asthma has its origins in early life. We review the epidemiological and biological evidence for fetal exposures that may have a causal role in asthma development. However, those factors that provoke asthma exacerbations are not necessarily the same as those associated with disease induction. Epidemiological studies have identified many potential exposures linked to asthma but these do not confirm causality and have not been replicated by experiment. Asthma is a heterogeneous disease and there are developmental influences on at least two pathways, airway structure and airway inflammation. The fetus is not immunologically naive and intrauterine exposures can act directly to invoke immunological sensitisation leading postnatally to airway inflammation. Other potential mechanisms include indirect effects on airway and lung growth through fetal nutrition and epigenetic modifications of DNA expression by environmental exposures. Identifying the causal factors will provide the targets for interventions to prevent disease.

Use of prescription paracetamol during pregnancy and risk of asthma in children: a population-based Danish cohort study

PURPOSE

Use of paracetamol during pregnancy may increase the risk of asthma in offspring. The association between prenatal exposure to maternal use of paracetamol and risk of asthma was investigated.

METHODS

A cohort study of 197,060 singletons born in northern Denmark in 1996-2008 was conducted, with follow-up until the end of 2009. Maternal paracetamol use during pregnancy was defined as a redeemed prescription. Asthma in offspring was defined as at least two prescriptions of both a β-agonist and an inhaled glucocorticoid and/or a hospital diagnosis of asthma during follow-up. Absolute risk of asthma in offspring was estimated using the Kaplan-Meier method and incidence rate ratios adjusted for known risk factors were estimated using Cox proportional-hazards regression.

RESULTS

Overall, 976 (0.5%) children were exposed prenatally to maternal use of prescription paracetamol. During follow-up, 24,506 (12.4%) children developed asthma. Absolute risk of asthma was 7.5% after 2 years and 14.4% after 10 years among the unexposed children. Corresponding risks were 12.7% and 21.6% among the exposed children. The adjusted incidence rate ratio was 1.35 (95% confidence interval: 1.17-1.57) for exposure in any trimester of pregnancy. A similar association was present for paracetamol exposure in each of the trimesters and for maternal use of prescription nonsteroidal anti-inflammatory drugs. Furthermore, maternal prescription use in the year following the relevant delivery also showed similar associations.

CONCLUSION

A robust association was found between prenatal exposure to maternal use of prescription paracetamol and the risk of asthma; however, noncausal explanations could not be ruled out for such association.

The consequences of obesity and excess weight gain in pregnancy

The prevalence of obesity in pregnancy is rising exponentially; about 15–20% of pregnant women now enter pregnancy with a BMI which would define them as obese. This paper provides a review of the strong links between obesity and adverse pregnancy outcome which operate across a range of pregnancy complications. For example, obesity is associated with an increased risk of maternal mortality, gestational diabetes mellitus, thromboembolism, pre-eclampsia and postpartum haemorrhage. Obesity also complicates operative delivery; it makes operative delivery more difficult, increases complications and paradoxically increases the need for operative delivery. The risk of the majority of these complications is amplified by excess weight gain in pregnancy and increases in proportion to the degree of obesity, for example, women with extreme obesity have OR of 7·89 for gestational diabetes and 3·84 for postpartum haemorrhage compared to their lean counterparts. The consequences of maternal obesity do not stop once the baby is born. Maternal obesity programmes a variety of long-term adverse outcomes, including obesity in the offspring at adulthood. Such an effect is mediated at least in part via high birthweight; a recent study has suggested that the odds of adult obesity are two-fold greater in babies weighing more than 4 kg at birth. The mechanism by which obesity causes adverse pregnancy outcome is uncertain. This paper reviews the emerging evidence that hyperglycaemia and insulin resistance may both play a role: the links between hyperglycaemia in pregnancy and both increased birthweight and insulin resistance have been demonstrated in two large studies. Lastly, we discuss the nature and rationale for possible intervention strategies in obese pregnant women.