Maternal Infection in Pregnancy and Risk of Asthma in Offspring

Contributions of maternal prenatal infection and antibiotic exposure to offspring infection and risk for allergic respiratory conditions through age 5

Objectives

To determine if maternal prenatal infection increases risk of offspring postnatal infections through age 5 or diagnosis of respiratory allergy at age 5, independent of prenatal/postnatal antibiotic exposure. To evaluate if frequency of offspring infections mediates an association between prenatal infection and respiratory allergy at age 5.

Study design

Secondary data analyses were performed from the Child Health and Development Studies (CHDS), a prospective, longitudinal birth cohort that enrolled pregnant women from 1959 to 1966 (N = 19,044 live births). The sample included a subset of mother-offspring dyads (n = 2062) with abstracted medical record data from the prenatal period through age 5 that included information on antibiotic use, infection, and offspring respiratory allergy.

Results

Second trimester maternal infection was associated with an increased risk of offspring infection (IRR = 1.23; 95% CI = 1.09-1.39; p = 0.001). No significant direct associations were detected between prenatal infection and diagnosis of offspring respiratory allergy. Offspring infection (OR = 1.17; 95% CI = 1.13-1.20; p < 0.001) and antibiotic exposure (OR = 1.28; 95% CI = 1.22-1.33; p < 0.001) were significantly associated with a diagnosis of offspring respiratory allergy. Respiratory allergy diagnosis risk was greater with increasing offspring infection exposure and antibiotics. There was a significant indirect effect of second trimester maternal infection on offspring respiratory allergy, due to infections and not antibiotic use, via offspring infection, indicating a partially mediated effect.

Conclusion

Prenatal maternal infection may contribute to increase risk for early childhood infections, which in turn, may increase risk for allergic conditions.

Betamethasone improved near-term neonatal lamb lung maturation in experimental maternal asthma

Maternal asthma is associated with increased rates of neonatal lung disease, and fetuses from asthmatic ewes have fewer surfactant-producing cells and lower surfactant-protein B gene (SFTPB) expression than controls. Antenatal betamethasone increases lung surfactant production in preterm babies, and we therefore tested this therapy in experimental maternal asthma. Ewes were sensitised to house dust mite allergen, and an asthmatic phenotype induced by fortnightly allergen lung challenges; controls received saline. Pregnant asthmatic ewes were randomised to receive antenatal saline (asthma) or 12 mg intramuscular betamethasone (asthma+beta) at 138 and 139 days of gestation (term = 150 days). Lambs were delivered by Caesarean section at 140 days of gestation and ventilated for 45 min before tissue collection. Lung function and structure were similar in control lambs (n = 16, 11 ewes) and lambs from asthma ewes (n = 14, 9 ewes). Dynamic lung compliance was higher in lambs from asthma+beta ewes (n = 12, 8 ewes) compared to those from controls (P = 0.003) or asthma ewes (P = 0.008). Lung expression of surfactant protein genes SFTPA (P = 0.048) and SFTPB (P < 0.001), but not SFTPC (P = 0.177) or SFTPD (P = 0.285), was higher in lambs from asthma+beta than those from asthma ewes. Female lambs had higher tidal volume (P = 0.007), dynamic lung compliance (P < 0.001), and SFTPA (P = 0.037) and SFTPB gene expression (P = 0.030) than males. These data suggest that betamethasone stimulates lung maturation and function of near-term neonates, even in the absence of impairment by maternal asthma.

Prenatal exposure to common infections and newborn DNA methylation: A prospective, population-based study

BACKGROUND

Infections during pregnancy have been robustly associated with adverse mental and physical health outcomes in offspring, yet the underlying molecular pathways remain largely unknown. Here, we examined whether exposure to common infections in utero associates with DNA methylation (DNAm) patterns at birth and whether this in turn relates to offspring health outcomes in the general population.

METHODS

Using data from 2,367 children from the Dutch population-based Generation R Study, we first performed an epigenome-wide association study to identify differentially methylated sites and regions at birth associated with prenatal infection exposure. We also examined the influence of infection timing by using self-reported cumulative infection scores for each trimester. Second, we sought to develop an aggregate methylation profile score (MPS) based on cord blood DNAm as an epigenetic proxy of prenatal infection exposure and tested whether this MPS prospectively associates with offspring health outcomes, including psychiatric symptoms, BMI, and asthma at ages 13-16 years. Third, we investigated whether prenatal infection exposure associates with offspring epigenetic age acceleration - a marker of biological aging. Across all analysis steps, we tested whether our findings replicate in 864 participants from an independent population-based cohort (ALSPAC, UK).

RESULTS

We observed no differentially methylated sites or regions in cord blood in relation to prenatal infection exposure, after multiple testing correction. 33 DNAm sites showed suggestive associations (p < 5e10 - 5; of which one was also nominally associated in ALSPAC), indicating potential links to genes associated with immune, neurodevelopmental, and cardiovascular pathways. While the MPS of prenatal infections associated with maternal reports of infections in the internal hold out sample in the Generation R Study (R2incremental = 0.049), it did not replicate in ALSPAC (R2incremental = 0.001), and it did not prospectively associate with offspring health outcomes in either cohort. Moreover, we observed no association between prenatal exposure to infections and epigenetic age acceleration across cohorts and clocks.

CONCLUSION

In contrast to prior studies, which reported DNAm differences in offspring exposed to severe infections in utero, we do not find evidence for associations between self-reported clinically evident common infections during pregnancy and DNAm or epigenetic aging in cord blood within the general pediatric population. Future studies are needed to establish whether associations exist but are too subtle to be statistically meaningful with present sample sizes, whether they replicate in a cohort with a more similar infection score as our discovery cohort, whether they occur in different tissues than cord blood, and whether other biological pathways may be more relevant for mediating the effect of prenatal common infection exposure on downstream offspring health outcomes.

Maternal asthma during pregnancy and risks of allergy and asthma in progeny: A systematic review and meta-analysis

BACKGROUND

Clinical and preclinical evidence indicate that in utero maternal asthma exposure increases progeny asthma risk. Whether maternal asthma also increases the risks of progeny allergy is unclear.

OBJECTIVES

To synthesise the available evidence on the relationship between in utero exposure to maternal asthma and postnatal asthma, wheezing and allergic diseases (Prospero: CRD42020201538).

SEARCH STRATEGY

We systematically searched MEDLINE [PubMed], Embase [Ovid], Web of Science, Informit Health, the Cochrane Library, CINAHL [EBSCOhost], MedNar [Deep Web Technologies], ProQuest Theses and Dissertations, Scopus [Elsevier] and Trove, to the end of 2023.

SELECTION CRITERIA

Studies reporting asthma, wheeze and/or allergic disease in progeny of women with and without asthma or with asthma classified by control, exacerbation or severity.

DATA COLLECTION AND ANALYSIS

Double screening, selection, data extraction and quality assessment were performed, using Joanna Briggs Institute (JBI) scoring.

MAIN RESULTS

Of 134 non-overlapping studies, 127 were included in ≥1 meta-analysis. Maternal asthma ever was associated with greater risks of asthma (65 studies, risk ratio [95% confidence interval] 1.76 [1.57-1.96]), wheeze (35 studies, 1.59 [1.52-1.66]), food allergy (5 studies, 1.32 [1.23-1.40]), allergic rhinitis (7 studies, 1.18 [1.06-1.31]) and allergic dermatitis (14 studies, 1.17 [1.11-1.23]) ever in progeny. Asthma during the pregnancy, more severe, and uncontrolled maternal asthma were each associated with greater risks of progeny asthma.

CONCLUSIONS

Children of mothers with asthma are at increased risk for the development of allergic diseases. Whether improved maternal asthma control reduces risks of child allergy as well as asthma requires further investigation.

Maternal antibiotic use and infections during pregnancy and offspring asthma: the Norwegian Mother, Father and Child Cohort Study and a nationwide register cohort

Maternal antibiotic use during pregnancy has been linked to asthma risk in children, but the role of underlying infections remains unclear. We investigated the association of maternal antibiotic use and infections during pregnancy with offspring risk of asthma. We used two population-based cohorts: the Norwegian Mother, Father and Child Cohort Study (MoBa) (n = 53 417) and a register-based cohort (n = 417 548). Asthma was defined based on dispensed asthma medications at 7 and 13 years from the Norwegian Prescription Database. Self-reported information on antibiotic use and infections during pregnancy was available in MoBa, while registrations of dispensed prescriptions were used to classify use of antibiotics in the register-based cohort. Maternal antibiotic use during pregnancy was associated with asthma at 7 in both cohorts (adjusted risk ratio (aRR) 1.23, 95% CI 1.11-1.37 in MoBa and 1.21, 1.16-1.25 in the register cohort) and asthma at 13 in the register cohort (1.13, 1.03-1.23) after adjusting for maternal characteristics. In MoBa, the estimate was attenuated after adjusting for infections during pregnancy. Maternal lower and upper respiratory tract infections (aRR 1.30, 95% CI 1.07-1.57 and 1.19, 1.09-1.30, respectively) and urinary tract infections (1.26, 1.11-1.42) showed associations with asthma at 7. Register cohort also showed an increased risk of asthma in relation to maternal antibiotics before and after pregnancy. Our findings suggest that both maternal antibiotics and infections during pregnancy have a role in the risk of offspring asthma. However, results from the register cohort suggest that the effect of antibiotics may reflect the shared underlying susceptibility.

Association between prenatal and neonatal factors and occurrence of asthma symptoms in six-year-old children

Abstract The objective was to estimate association between prenatal and neonatal factors and asthma symptoms in children at six years of age. A cross-sectional study using secondary data from a cohort study with a sample of 578 children was carried out. Data were analyzed using three levels hierarchical Poisson Regression. Of the 578 children included in the study, 43.4% (95% CI 39.4; 47.4) had asthma symptoms. The variables with significantly higher prevalence of symptoms and asthma at six years of age were: male gender, with 5% higher prevalence (PR = 1.05 95% CI 1.01; 1.11) (p = 0.043); children of pregnant women presenting infectious diseases with 7% higher prevalence (PR = 1.07; 95% CI 1.02; 1.13) (p = 0.011); children who were not breastfed, with a 12% higher prevalence (PR = 1.12; 95% CI 1.02; 1.24) (p = 0.022) and children with respiratory problems in the first month of life, with a 14% higher prevalence (PR = 1.14; 95% CI 1.01; 1.29) (p = 0.033). It could be concluded that male gender, time-independent breastfeeding deprivation and respiratory problems in the first month of life were independently associated with asthma symptoms at six years of age. The occurrence of infectious diseases during pregnancy was the only factor with intrauterine physiology that was associated with the occurrence of asthma symptoms at six years of age.

Association between gestational hair dye use and allergies at 3 years old: the Japan environment and Children's study

BACKGROUND

Hair dye use frequently induces allergic contact dermatitis, and on rare occasions induces immunoglobulin E-mediated immediate urticaria, anaphylaxis, and asthma. The effects of hair dye use during pregnancy on offspring have been studied for carcinogenicity, but not for development of allergies. This study aimed to assess the association between hair dye use during pregnancy and allergic disease in children at 3 years old.

METHODS

Data of 77,303 participants from the Japan Environment and Children's Study, which is a prospective birth cohort recruited from January 2011 to March 2014, were used. We examined the associations between using hair dye during pregnancy and allergic diseases (food allergy, asthma, atopic dermatitis and allergic rhinitis) in children after adjustment for covariates by multivariable logistic regression.

RESULTS

Among mothers who were exposed to hair dye during pregnancy, 50.0% were exposed in hair salons, 21.3% had home use, and 9.5% had occupational exposure. The percentages of doctor-diagnosed allergies at 3 years old were 6.3% for food allergies, 7.7% for asthma, 7.3% for atopic dermatitis, and 4.6% for allergic rhinitis. In univariable analyses, hair dye use at home and occupational exposure was significantly associated with asthma respectively (odds ratio [OR] 1.15, 95% CI 1.07-1.24 for at home; OR 1.18, 95% CI 1.08-1.28 for occupational exposure). Hair dye use at home were significantly associated with doctor-diagnosed allergic rhinitis at 3 years old (OR 1.12, 95% CI 1.02-1.22). After adjustment for covariates, these associations for asthma decreased and were no longer significant (aOR 1.06, 95% CI 0.98-1.14 for at home; aOR 1.09, 95% CI 1.00-1.20 for occupational exposure, p = 0.057), also for allergic rhinitis (aOR 1.07, 95% CI 0.97-1.19). Doctor-diagnosed allergic rhinitis at 3 years old was significantly associated with hair dye use at home in the most frequent use group (aOR for quite often versus never 1.78, 95% CI 1.22-2.60).

CONCLUSION

Both home and occupation use of hair dye during pregnancy showed a trend of increased odds of allergic rhinitis and asthma in offspring at 3 years. However, the only association that reached significance was in frequency of use analyses between the highest frequency of home hair dye users and allergic rhinitis.

Antibiotic exposure during pregnancy and childhood asthma: a national birth cohort study investigating timing of exposure and mode of delivery

OBJECTIVE

To investigate whether antibiotic exposure during pregnancy was associated with childhood asthma and if this relationship was conditional on timing of exposure and mode of delivery.

DESIGN

A cohort study using multivariable logistic regression models adjusting for a priori defined confounders. Pregnant women were recruited from 1996 to 2002.

SETTING

The Danish National Birth Cohort.

PATIENTS

Of the 96 832 children in the cohort, 32 651 children were included in the study population.

MAIN OUTCOME MEASURE

Parent-reported childhood asthma at 11 years.

RESULTS

A total of 5522 (17%) children were born to mothers exposed to antibiotics during pregnancy. In adjusted analyses, children born to exposed mothers had higher odds of asthma (OR 1.14, 95% CI 1.05 to 1.24). There was no association with antibiotic exposure in the first trimester (OR 1.02, 95% CI 0.83 to 1.26), but higher odds were observed for antibiotic exposure in the second to third trimester (OR 1.17, 95% CI 1.06 to 1.28), compared with unexposed children. The overall association between antibiotics during pregnancy and childhood asthma was only observed in vaginally born children (OR 1.17, 95% CI 1.07 to 1.28) but not in caesarean section born children (planned caesarean section: OR 0.95, 95% CI 0.66 to 1.37; caesarean emergency: OR 0.96, 95% CI 0.73 to 1.28). In exposed vaginally born children, the odds for childhood asthma requiring treatment during the preceding year were 34% higher (OR 1.34, 95% CI 1.21 to 1.49), compared with unexposed vaginally born children.

CONCLUSIONS

Antibiotic exposure in mid-to-late pregnancy is associated with higher odds of childhood asthma in vaginally born children. Mode of delivery may modify the association.

Atopy risk among school-aged children in relation to early exposures to a farm environment: A systematic review

BACKGROUND AND OBJECTIVES

Childhood atopy is a complex condition with both a genetic and an environmental component. This systematic review will explore the current understanding of the importance of early life exposures to a farm in the development of atopy measured by objective markers of skin prick testing, and specific IgE measurements in school age children.

METHODS

A systematic review was performed.

RESULTS

Among 7285 references identified, 14 studies met the inclusion criteria (13 cross-sectional studies and 1 case-control study). The results were fairly consistent in that early farm-related exposures can protect children from becoming atopic at school age. In general, there was heterogeneity in the assessment of outcomes and exposures.

CONCLUSIONS

Early-life farm exposures are associated with a protective effect on childhood atopy as assessed by objective markers. Future work should focus on understanding specific farm exposures that may important in these associations between atopy and farm exposures in children.

Histological chorioamnionitis is associated with an increased risk of wheezing in preterm children less than 34 gestational weeks

Background

Chorioamnionitis is associated with various neonatal short- and long-term morbidities. The effect of chorioamnionitis on premature children’s outcomes remains controversial. The aim of this study is to investigate the relationship between histological chorioamnionitis (HCA) and physiological development, wheezing, and atopic diseases in preterm children.

Methods

Singleton, preterm children (< 34 weeks), whose mother underwent pathological placental examinations, were retrospectively enrolled and the outcomes were assessed at 24–40 months during follow-up. Wheezing and atopic diseases including eczema, food allergies, and allergic rhinitis were screened by a questionnaire along with medical diagnosis. Anthropometric indexes and blood pressure were measured. Cognitive and behavioural developments were assessed by the Gesell Development and Diagnosis Scale. Blood IgE and routine examination were analyzed with venous blood and serum metabolomic profiling was assessed via liquid chromatography-mass spectrometry (LC-MS). A multivariate logistic regression model was used to estimate the association between HCA and the current outcomes.

Results

Among the 115 enrolled children, 47 were exposed to HCA. The incidence of wheezing was significantly higher in children exposed to HCA, as 38.30% of children who were exposed to HCA and 16.18% of children who were not had been diagnosed with wheezing. After adjusting for related confounders in the multivariate logistic regression model, there remained a 2.72-fold increased risk of wheezing in children with HCA (adjusted odds ratio, aOR, 2.72; 95% confidence interval, 1.02–7.23). Moreover, 163 differential metabolites, such as butanoic acid, annotemoyin 1 and charine, were identified in the HCA exposed children’s serum. Enrichment analysis revealed that these compounds participated in diverse key metabolomic pathways relating to physical and neuro- developments, including glycerophospholipid, alpha-linolenic acid and choline metabolisms. There were no significant differences in atopic diseases, serum IgE, eosinophils’ level, anthropometric indexes, blood pressure, or cognitive or behavioural developments between the two groups.

Conclusion

HCA exposure is associated with an increased risk of wheezing in preterm children less than 34 gestational weeks.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02572-9.

Maternal biomarker patterns for metabolism and inflammation in pregnancy are influenced by multiple micronutrient supplementation and associated with child biomarker patterns and nutritional status at 9-12 years of age

Maternal nutritional status influences fetal development and long-term risk for adult non-communicable diseases. However, the underlying mechanisms remain poorly understood. We examined whether biomarkers for metabolism and inflammation during pregnancy were associated with maternal health and with child biomarkers and health at 9-12 years of age in 44 maternal-child dyads from the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT, ISRCTN34151616) in Lombok, Indonesia. Archived blood for each dyad from maternal enrollment, later in pregnancy, postpartum, and from children at 9-12 years comprised 132 specimens. Multiplex microbead immunoassays were used to quantify vitamin D-binding protein (D), adiponectin (A), retinol-binding protein 4 (R), C-reactive protein (C), and leptin (L). Principal component analysis (PCA) revealed distinct variance patterns, i.e. principal components (PC), for baseline pregnancy, bp.pc1.D↓A↓R↓ and bp.pc2.C↓L↑; combined follow-up during pregnancy and postpartum, dp-pp.pc1.D↑↓A↑R↑↓L↓ and dp-pp.pc2.A↑C↑L↑; and children, ch.pc1.D↑R↑C↑ and ch.pc2.D↓A↑L↑. Maternal multiple micronutrient (MMN) supplementation led to an association of baseline maternal bp.pc2.C↓L↑ with decreased post-supplementation maternal dp-pp.pc2.A↑C↑L↑ (p = 0.022), which was in turn associated with both increased child ch.pc1.D↑R↑C↑ (p = 0.036) and decreased child BMI z-score (BMIZ) (p = 0.022). Further analyses revealed an association between maternal dp-pp.pc1.D↑↓A↑R↑↓L↓ and increased child BMIZ (p = 0.036). Child ch.pc1.D↑R↑C↑ was associated with decreased birth weight (p = 0.036) and increased child BMIZ (p = 0.002). Child ch.pc2.D↓A↑L↑ was associated with increased child BMIZ (p = 0.005), decreased maternal height (p = 0.030) and girls (p = 0.002). A pattern of elevated maternal adiponectin and leptin in pregnancy was associated with increased C-reactive protein, vitamin A, and D binding proteins pattern in children, suggesting biomarkers acting in concert may have qualitative as well as quantitative influence beyond single biomarker effects. Patterns in pregnancy proximal to birth were more associated with child status. In addition, child patterns were more associated with child status, particularly child BMI. MMN supplementation affects maternal biomarker patterns of metabolism and inflammation in pregnancy, and potentially in the child. However, child nutrition conditions after birth may have a greater impact on metabolism and inflammation.

Pakistan Developmental Origins of Health and Disease (DOHaD) Society: addressing the 'DO' component of DOHaD

Adverse intrauterine environment could serve as an important stimulus for postnatal altered health status and for increased susceptibility to long-term non-communicable diseases (NCDs). The notion is now recognized as the Developmental Origins of Health and Disease (DOHaD), which was first proposed by Sir David Barker. Since then, several scientific disciplines have strived to measure the magnitude of the early fetal programming and later risk of diseases. Pakistan, with striking figures of morbidity and mortality from NCDs, is currently tackling with double burden of diseases and requires planned efforts to counteract the threat of NCDs. Considering the growing needs and available evidences, Pakistan DOHaD Society was officially instigated in September 2016. The Society aims to explicitly address the association of life in utero with future health and disease and to endorse early screening and interventions to reduce the burden of NCDs, mental health issues and learning disorders along the life course. It has shown significant progress toward investigating the influence of adverse in utero environment such as diabetes, maternal under-nutrition and pre-eclampsia on fetal programming under two major research lines, that is, cardiovascular and cerebrovascular programming. The Society has been successful in disseminating its research findings through several esteemed international scientific conferences. Pakistan DOHaD Society encourages scientific community for collaborative research aimed at improving the quality of life during early childhood, adolescence and adulthood through provision of appropriate pre-pregnancy and antenatal interventions targeted to address at-risk in utero conditions.

Relevance of the first thousand days of life to the development of wheezing in children aged 6-7 years

INTRODUCTION

The first thousand days of life are a critical stage for the development of respiratory and immune systems. Many events in this period may be associated with wheezing in childhood.

OBJECTIVE

This study aimed to investigate the association between early life determinants and wheezing in children aged 6-7 years.

MATERIALS AND METHODS

Population-based case-control study using early-life related questions. We used the International Study of Asthma and Allergies in Childhood questionnaire to assess wheezing symptoms. Multiple logistic regressions were performed according to a hierarchical framework, considering the complex dynamic of wheezing/asthma and potential interaction between different levels of determination.

RESULTS

A total of 820 children were included, from which 162 reported wheezing symptoms (19.7%). Multivariable analysis identified socioeconomic conditions (OR 2.08, 95% CI 1.08-4.00), family history of asthma (OR 2.28, 95% CI 1.37-3.75), vaginal discharge that required treatment during pregnancy (OR 1.68, 95% CI 1.00-2.83), neonatal hyperbilirubinemia (OR 2.00, 95% CI 1.17-3.42), anemia and intestinal parasitosis in the first two years (OR 2.28, 95% CI 1.22-4.25; OR 1.72, 95% CI 1.02-2.92, respectively) independently associated to wheezing at 6-7 years. Intended pregnancy was associated with reduced wheezing (OR 0.47, 95% CI 0.28-0.77).

CONCLUSIONS

Several factors were associated with wheezing in childhood. Considering that intended pregnancy reduced wheezing and other associated exposures are considered modifiable, these findings may guide the planning of strategies to decrease the susceptibility to asthma symptoms in childhood.

Maternal malaria but not schistosomiasis is associated with a higher risk of febrile infection in infant during the first 3 months of life: A mother-child cohort in Benin

Background

Malaria and schistosomiasis represent two of the most prevalent and disabling parasitic infections in developing countries. Few studies have evaluated the effect of maternal schistosomiasis and malaria in the peri-conceptional period on infant’s risk of infection.

Methods

In Benin, women were followed from the preconception period until delivery. Subsequently, their children were followed from birth to 3 months of age. Pre-pregnancy malaria, malaria in pregnancy (MiP)—determined monthly using a thick blood smear—and urinary schistosomiasis—determined once before pregnancy and once at delivery using urine filtration—were the main maternal exposures. Infant’s febrile infection (fever with respiratory, gastrointestinal and/or cutaneous clinical signs anytime during follow-up) was the main outcome. In a secondary analysis, we checked the relation of malaria and schistosomiasis with infant’s hemoglobin (Hb) concentration. Both effects were separately assessed using logistic/mixed linear regression models.

Results

The prevalence of MiP was 35.7% with 10.8% occurring during the 1^st trimester, and the prevalence of schistosomiasis was 21.8%. From birth to 3 months, 25.3% of infants had at least one episode of febrile infection. In multivariate analysis, MiP, particularly malaria in the 1^st trimester, was significantly associated with a higher risk of infant’s febrile infection (aOR = 4.99 [1.1; 22.6], p = 0.03). In secondary results, pre-pregnancy malaria and schistosomiasis were significantly associated with a lower infant’s Hb concentration during the first 3 months.

Conclusion

We evidenced the deleterious effect of maternal parasitic infections on infant’s health. Our results argue in favor of the implementation of preventive strategies as early as in the peri-conception.

Life Cycle of Childhood Asthma: Prenatal, Infancy and Preschool, Childhood, and Adolescence

Asthma is a heterogeneous developmental disorder influenced by complex interactions between genetic susceptibility and exposures. Wheezing in infancy and early childhood is highly prevalent, with a substantial minority of children progressing to established asthma by school age, most of whom are atopic. Adolescence is a time of remission of symptoms with persistent lung function deficits. The transition to asthma in adulthood is not well understood.

The effect of breastfeeding on the risk of asthma in high-risk children: a case-control study in Shanghai, China

BACKGROUND

Increasing evidence shows that antibiotic use in pregnancy may increase the risk of childhood asthma but epidemiologic studies are still limited and findings are inconsistent. Meanwhile, exclusive and prolonged breastfeeding may prevent children from allergic diseases. We aimed to assess the association between prenatal antibiotic use and the risk of childhood asthma, and explore whether breastfeeding modifies the risk.

METHODS

We conducted a case-control study in Shanghai, China, from June 2015 to January 2016. A total of 634 asthma cases and 864 controls aged 3-12 years were included. Multiple logistic regressions were used to estimate crude and adjusted odds ratios (aOR).

RESULTS

The prevalence of antibiotic use in pregnancy in the cases and controls was 7.1 and 3.5%, respectively. A significant association between prenatal antibiotic use and childhood asthma was observed (aOR: 1.7, 95% CI: 1.0-2.9), particularly in boys (aOR: 2.2, 95% CI: 1.1-4.4) and children with family history of allergic disorders (aOR: 3.1, 95% CI: 1.2-8.4). However, this association existed only in children who were not breastfed exclusively in the first six months of life (aOR 2.6, 95% CI 1.3-5.1) but not in children who were exclusively breastfed (aOR 0.9, 95% CI 0.4-2.1). Likewise, exclusive breastfeeding also decreased the association between antibiotic use in pregnancy and asthma in boys and in children with family histories of allergic diseases.

CONCLUSIONS

Antibiotic use in pregnancy was a risk factor for childhood asthma. However, this risk may be attenuated by exclusive breastfeeding in the first six months of life, especially among high-risk children.

Prenatal antibiotic exposure and childhood asthma: a population-based study

Antibiotic use during infancy alters gut microbiota and immune development and is associated with an increased risk of childhood asthma. The impact of prenatal antibiotic exposure is unclear. We sought to characterise the association between prenatal antibiotic exposure and childhood asthma.We performed a population-based cohort study using prescription records, hospitalisation records and physician billing claims from 213 661 mother-child dyads born in Manitoba, Canada between 1996 and 2012. Associations were determined using Cox regression, adjusting for maternal asthma, postnatal antibiotics and other potential confounders. Sensitivity analyses evaluated maternal antibiotic use before and after pregnancy.36.8% of children were exposed prenatally to antibiotics and 10.1% developed asthma. Prenatal antibiotic exposure was associated with an increased risk of asthma (adjusted hazard ratio (aHR) 1.23, 95% CI 1.20-1.27). There was an apparent dose response (aHR 1.15, 95% CI 1.11-1.18 for one course; aHR 1.26, 95% CI 1.21-1.32 for two courses; and aHR 1.51, 95% CI 1.44-1.59 for three or more courses). Maternal antibiotic use during 9 months before pregnancy (aHR 1.27, 95% CI 1.24-1.31) and 9 months postpartum (aHR 1.32, 95% CI 1.28-1.36) were similarly associated with asthma.Prenatal antibiotic exposure was associated with a dose-dependent increase in asthma risk. However, similar associations were observed for maternal antibiotic use before and after pregnancy, suggesting the association is either not directly causal, or not specific to pregnancy.

Gastro-oesophageal reflux: a mixed methods study of infants admitted to hospital in the first 12 months following birth in NSW (2000-2011)

BACKGROUND

Gastro-oesophageal reflux (GOR) is common in infants. When the condition causes pathological symptoms and/or complications it is considered gastro-oesophageal reflux disease (GORD). It appears to be increasingly diagnosed and causes great distress in the first year of infancy. In New South Wales (NSW), residential parenting services support families with early parenting difficulties. These services report a large number of babies admitted with a label of GOR/GORD. The aim of this study was to explore the maternal and infant characteristics, obstetric interventions, and reasons for clinical reporting of GOR/GORD in NSW in the first 12 months following birth (2000-2011).

METHODS

A three phase, mixed method sequential design was used. Phase 1 included a linked data population based study (n = 869,188 admitted babies). Phase 2 included a random audit of 326 medical records from admissions to residential parenting centres in NSW (2013). Phase 3 included eight focus groups undertaken with 45 nurses and doctors working in residential parenting centres in NSW.

RESULTS

There were a total of 1,156,020 admissions recorded of babies in the first year following birth, with 11,513 containing a diagnostic code for GOR/GORD (1% of infants admitted to hospitals in the first 12 months following birth). Babies with GOR/GORD were also more likely to be admitted with other disorders such as feeding difficulties, sleep problems, and excessive crying. The mothers of babies admitted with a diagnostic code of GOR/GORD were more likely to be primiparous, Australian born, give birth in a private hospital and have: a psychiatric condition; a preterm or early term infant (37-or-38 weeks); a caesarean section; an admission of the baby to SCN/NICU; and a male infant. Thirty six percent of infants admitted to residential parenting centres in NSW had been given a diagnosis of GOR/GORD. Focus group data revealed two themes: "It is over diagnosed" and "A medical label is a quick fix, but what else could be going on?"

CONCLUSIONS

Mothers with a mental health disorder are nearly five times as likely to have a baby admitted with GOR/GORD in the first year after birth. We propose a new way of approaching the GOR/GORD issue that considers the impact of early birth (immaturity), disturbance of the microbiome (caesarean section) and mental health (maternal anxiety in particular).

[Association between risk factors during maternal pregnancy and the neonatal period and childhood bronchial asthma]

OBJECTIVE

To study the association of the risk factors during maternal pregnancy and the neonatal period with childhood bronchial asthma.

METHODS

A total of 306 children with asthma (asthma group) and 250 healthy children (control group) were enrolled. Their clinical data during the neonatal period and the maternal data during pregnancy were retrospectively studied.

RESULTS

The univariate analysis showed that there were significant differences in the rates of maternal use of antibiotics during pregnancy, use of antibiotics and probiotics during the neonatal period, preterm birth, cesarean section, low birth weight, and breast feeding (>6 months) between the asthma and control groups (P<0.05). The multivariate logistic regression analysis showed that use of antibiotics during pregnancy (OR=3.908, 95%CI: 1.277-11.962), use of antibiotics during neonatal period (OR=24.154, 95%CI: 7.864-74.183), preterm birth (OR=8.535, 95%CI: 2.733-26.652), and cesarean section (OR=4.588, 95%CI: 2.887-7.291) were independent risk factors for childhood asthma. The use of probiotics during the neonatal period (OR=0.014, 95%CI: 0.004-0.046) and breast feeding (>6 months) (OR=0.161, 95%CI: 0.103-0.253) were protective factors for childhood asthma.

CONCLUSIONS

The early prevention of childhood asthma can be improved by reducing the use of antibiotics during pregnancy, reducing cesarean section, avoiding abuse of antibiotics during the neonatal period, trying breast feeding and taking probiotics in early stage.

Meta-analysis of antenatal infection and risk of asthma and eczema

BACKGROUND

The influence of maternal infection during pregnancy on allergic disorders in offspring is not well understood. We performed a systematic review and meta-analysis to evaluate current evidence on the association between maternal infection during pregnancy and asthma or eczema in offspring.

METHODS

We searched databases (PubMed, EMBASE, Medline, and Web of Science) for all relevant studies published before March 2016. Any cohort studies, case-control studies, or cross-sectional studies published in English and focused on the association between maternal infection during pregnancy and the risk of asthma or eczema in offspring were included. Random-effects models were used for combined analyses.

RESULTS

A total of 10 studies with 299,830 participants were included. Maternal infection was associated with an increased risk for asthma (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.24-1.92; P < 0.01) and eczema (OR: 1.36; 95% CI: 1.13-1.64; P < 0.01). Further analyses showed associations between asthma and several specific maternal infections: fever episode (OR: 1.73; 95% CI: 1.35-2.23), chorioamnionitis (OR: 1.42; 95% CI: 0.96-2.11), respiratory infection (OR: 1.49; 95% CI: 0.94-2.36), and urogenital infection (OR: 1.39; 95% CI: 1.18-1.64).

CONCLUSION

The results from this meta-analysis and systematic review provide evidence that maternal infection during pregnancy might be related to subsequent asthma and eczema in offspring. However, there was variation of included studies with regard to type of maternal infection, age of children, and methods of exposure ascertainment. Additional studies are needed to further confirm these associations.

Effects of antenatal lipopolysaccharide and postnatal hyperoxia on airway reactivity and remodeling in a neonatal mouse model

BACKGROUND

Antenatal inflammation and preterm birth are associated with the development of airway diseases such as wheezing and asthma. Utilizing a newborn mouse model, we assessed the effects of maternal inflammation and postnatal hyperoxia on the neonatal airway.

METHODS

Pregnant C57/Bl6 dams were injected with lipopolysaccharide (LPS) or saline on embryonic day 16. Offspring were placed in room air or hyperoxia (50% O2) for 7 d and then returned to normoxia. Airway mechanics, histology, and laser capture micro-dissection (LCM) were performed.

RESULTS

At postnatal day 21, maternal LPS- and 50% O2-exposed pups exhibited increased resistance and decreased compliance compared to 21% O2 pups; however their effects were not synergistic. LPS and hyperoxia each increased the thickness of airway smooth muscle (ASM), but not the airway epithelial layer. Structural changes were largely limited to the conducting airways. Upregulation of inflammatory markers in the lung was observed at birth. LCM revealed increased collagen-3, transforming growth factor β, and connective tissue growth factor expression with LPS and hyperoxia within the ASM layer.

CONCLUSION

These novel studies provide functional, structural, and molecular evidence that antenatal inflammation is detrimental to the developing airway. Exposure to moderate hyperoxia does not exacerbate LPS effects on the airway.

Childbirth and consequent atopic disease: emerging evidence on epigenetic effects based on the hygiene and EPIIC hypotheses

BACKGROUND

In most high and middle income countries across the world, at least 1:4 women give birth by cesarean section. Rates of labour induction and augmentation are rising steeply; and in some countries up to 50% of laboring women and newborns are given antibiotics. Governments and international agencies are increasingly concerned about the clinical, economic and psychosocial effects of these interventions.

DISCUSSION

There is emerging evidence that certain intrapartum and early neonatal interventions might affect the neonatal immune response in the longer term, and perhaps trans-generationally. Two theories lead the debate in this area. Those aligned with the hygiene (or 'Old Friends') hypothesis have examined the effect of gut microbiome colonization secondary to mode of birth and intrapartum/neonatal pharmacological interventions on immune response and epigenetic phenomena. Those working with the EPIIC (Epigenetic Impact of Childbirth) hypothesis are concerned with the effects of eustress and dys-stress on the epigenome, secondary to mode of birth and labour interventions. This paper examines the current and emerging findings relating to childbirth and atopic/autoimmune disease from the perspective of both theories, and proposes an alliance of research effort. This is likely to accelerate the discovery of important findings arising from both approaches, and to maximize the timely understanding of the longer-term consequences of childbirth practices.

Prenatal exposure to antibiotics and wheezing in infancy: a birth cohort study

The role of prenatal antibiotic exposure in the development of childhood wheezing is debated. We evaluated whether this association could potentially be explained by confounding factors.Antibiotic use in the first and third trimester of pregnancy, wheezing in children aged ≤18 months and confounding factors were assessed in singletons participating in the NINFEA (Nascita e Infanzia: gli Effetti dell'Ambiente) birth cohort (n=3530 for first-trimester exposure and n=3985 for third-trimester exposure).There was no evidence of an association between antibiotic exposure in the first trimester of pregnancy and ever-wheezing (adjusted risk ratio (RR) 1.02, 95% CI 0.80-1.30) or recurrent wheezing (RR 0.99, 95% CI 0.54-1.82). For the third-trimester exposure, the crude RRs (95% CI) of ever-wheezing and recurrent wheezing were 1.34 (1.10-1.64) and 2.72 (1.80-4.11), respectively, which decreased to 1.12 (0.90-1.39) and 2.09 (1.32-3.29) after adjustment. The RRs of wheezing after genitourinary infections during pregnancy were increased independently of antibiotic treatment.In conclusion, the association between prenatal antibiotic exposure and infant wheezing could be largely explained by confounding factors, in particular respiratory infections during pregnancy. An excess risk of wheezing after antibiotic exposure during the third trimester of pregnancy remains after adjustment.

Periconceptional and Gestational Exposure to Antibiotics and Childhood Asthma

Background

Previous studies suggest that maternal antibiotics exposure during pregnancy may increase the risk of childhood asthma, but the results were inconsistent. Furthermore, most studies did not examine periconception period as an exposure window. We aim to assess the associations between maternal exposure to specific antibiotics before and during pregnancy and the risk of asthma in early childhood.

Methods

Data from the Collaborative Perinatal Project were used. Maternal exposure to antibiotics before and during pregnancy was recorded at each prenatal visit. A total of 39,907 singleton children were followed up to 7 years of age. Multilevel multiple logistic regression models were used to control for potential confounders and account for multiple pregnancies per woman.

Results

Maternal use of penicillin or chloramphenicol was associated with an increased risk of asthma in the offspring (adjusted odds ratio = 1.21, 95% confidence interval 1.08–1.36 for penicillin; 1.72 [1.14–2.59] for chloramphenicol). The risk was significantly increased if penicillin or chloramphenicol was used in the 1st trimester (1.09 [1.04–1.13] for penicillin and 1.23 [1.01–1.51] for chloramphenicol).

Conclusion

Maternal exposure to certain antibiotics is associated with childhood asthma by 7 years of age. Early pregnancy may be a sensitive window.

Fishmeal supplementation during ovine pregnancy and lactation protects against maternal stress-induced programming of the offspring immune system

BACKGROUND

Prenatally stressed offspring exhibit increased susceptibility to inflammatory disorders due to in utero programming. Research into the effects of n-3 PUFAs shows promising results for the treatment and prevention of these disorders. The purpose of this study was to investigate whether maternal fishmeal supplementation during pregnancy and lactation protects against programming of the offspring's immune response following simulated maternal infection.

METHODS

In order to accomplish this, 53 ewes were fed a diet supplemented with fishmeal (FM; rich in n-3 PUFA) or soybean meal (SM; rich in n-6 PUFAs) from day 100 of gestation (gd 100) through lactation. On gd135, half the ewes from each dietary group were challenged with either 1.2 μg/kg Escherichia coli lipopolysaccharide (LPS) endotoxin to simulate a bacterial infection, or saline as the control. At 4.5 months of age the offspring's dermal immune response was assessed by cutaneous hypersensitivity testing with ovalbumin (OVA) and candida albicans (CAA) 21 days after sensitization. Skinfold measurements were taken and serum blood samples were also collected to assess the primary and secondary antibody immune response.

RESULTS

Offspring born to SM + LPS mothers had a significantly greater change in skinfold thickness in response to both antigens as well as a greater secondary antibody response to OVA compared to all treatments.

CONCLUSIONS

Supplementation during pregnancy with FM appears to protect against adverse fetal programming that may occur during maternal infection and this may reduce the risk of atopic disease later in life.

Does allergy begin in utero?

It has been recognized for centuries that allergic disease runs in families, implying a role for genetic factors in determining individual susceptibility. More recently, a range of evidence shows that many of these genetic factors, together with in utero environmental exposures, lead to the development of allergic disease through altered immune and organ development. Environmental exposures during pregnancy including diet, nutrient intake and toxin exposures can alter the epigenome and interact with inherited genetic and epigenetic risk factors to directly and indirectly influence organ development and immune programming. Understanding of these factors will be essential in identifying at-risk individuals and possible development of therapeutic interventions for the primary prevention of allergic disease. In this review, we summarize the evidence that suggests allergic disease begins in utero, together with possible mechanisms for the effect of environmental exposures during pregnancy on allergic disease risk, including epigenetics.

Chronic lung disease of prematurity and early childhood wheezing: is foetal inflammatory response syndrome to blame?

BACKGROUND

Long-lasting respiratory symptoms have a huge impact on the quality of life in prematurely born children.

AIMS

We aimed to investigate the perinatal and maternal risk factors involved in the development of chronic respiratory morbidity in preterm infants, with an emphasis on the importance of Foetal Inflammatory Response Syndrome (FIRS).

STUDY DESIGN

Prospective cohort study.

SUBJECTS

Demographic, antenatal, delivery and outcomes data were collected from 262 infants with less than 32 completed weeks of gestational age, over a 10-year period.

OUTCOME MEASURES

Presence of chronic lung disease of prematurity and early childhood wheezing.

RESULTS

In multivariate logistic regression analysis the presence of FIRS appears to be the most important risk factor for both, chronic lung disease of prematurity (OR 31.05, 95% CI 10.7-87.75, p<0.001) and early childhood wheezing (OR 5.63, 95% CI 2.42-13.05, p=0.01). In the alternative regression model for early childhood wheezing, with chronic lung disease included as a variable, the statistical significance of FIRS completely vanished (OR 1.15, 95% CI 0.39-3.34, p=0.79), whilst chronic lung disease became the most important risk factor (OR 23.45, 95% CI 8.5-63.25, p<0.001).

CONCLUSIONS

Prenatal and early neonatal events are of utmost importance in the development of chronic respiratory symptoms in children. The influence of FIRS on the development of chronic respiratory symptoms goes far beyond its impact on gestational age and may be related to direct inflammation-mediated lung tissue damage. CLD appears to be an intermittent step on the way from FIRS to ECW.

Systemic inflammation in the extremely low gestational age newborn following maternal genitourinary infections

PROBLEM

Gestational genitourinary infections are associated with lifelong disabilities, but it is unknown if neonatal inflammation is involved.

METHOD

Mothers of 914 infants born before 28th gestation week reported cervical/vaginal infection (CVI), and/or urine/bladder/kidney infection (UTI), or neither. Inflammation proteins measured in baby's blood on postnatal days 1, 7, and 14 were considered elevated if in the top quartile for gestational age. Logistic regression models adjusting for potential confounders assessed odds ratios.

RESULTS

Compared to mothers with neither UTI/CVI, those with CVI were more likely to have infants with elevated CRP, SAA, MPO, IL-1β, IL-6, IL-6R, TNF-α, RANTES, ICAM-3, E-selectin, and VEGF-R2 on day 1; those with UTI were more likely to have infants with elevated MPO, IL-6R, TNF-R1, TNF-R2, and RANTES on day 7. Placental anaerobes and genital mycoplasma were more common in pregnancies with CVI.

CONCLUSION

Gestational UTI/CVI should be targeted for preventing systemic inflammation in the very preterm newborn.

Preterm birth and childhood wheezing disorders: a systematic review and meta-analysis

BACKGROUND

Accumulating evidence implicates early life factors in the aetiology of non-communicable diseases, including asthma/wheezing disorders. We undertook a systematic review investigating risks of asthma/wheezing disorders in children born preterm, including the increasing numbers who, as a result of advances in neonatal care, now survive very preterm birth.

METHODS AND FINDINGS

Two reviewers independently searched seven online databases for contemporaneous (1 January 1995-23 September 2013) epidemiological studies investigating the association between preterm birth and asthma/wheezing disorders. Additional studies were identified through reference and citation searches, and contacting international experts. Quality appraisal was undertaken using the Effective Public Health Practice Project instrument. We pooled unadjusted and adjusted effect estimates using random-effects meta-analysis, investigated "dose-response" associations, and undertook subgroup, sensitivity, and meta-regression analyses to assess the robustness of associations. We identified 42 eligible studies from six continents. Twelve were excluded for population overlap, leaving 30 unique studies involving 1,543,639 children. Preterm birth was associated with an increased risk of wheezing disorders in unadjusted (13.7% versus 8.3%; odds ratio [OR] 1.71, 95% CI 1.57-1.87; 26 studies including 1,500,916 children) and adjusted analyses (OR 1.46, 95% CI 1.29-1.65; 17 studies including 874,710 children). The risk was particularly high among children born very preterm (<32 wk gestation; unadjusted: OR 3.00, 95% CI 2.61-3.44; adjusted: OR 2.81, 95% CI 2.55-3.12). Findings were most pronounced for studies with low risk of bias and were consistent across sensitivity analyses. The estimated population-attributable risk of preterm birth for childhood wheezing disorders was ≥3.1%. Key limitations related to the paucity of data from low- and middle-income countries, and risk of residual confounding.

CONCLUSIONS

There is compelling evidence that preterm birth-particularly very preterm birth-increases the risk of asthma. Given the projected global increases in children surviving preterm births, research now needs to focus on understanding underlying mechanisms, and then to translate these insights into the development of preventive interventions.

REVIEW REGISTRATION

PROSPERO CRD42013004965.

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.

Prenatal and childhood infections: implications for the development and treatment of childhood asthma

Bacterial and viral infections occur early and recurrently in life and thereby impose a substantial disease burden. Besides causing clinical symptoms, a potential role of infection in the development of the asthma syndrome later in life has also been suggested. However, whether bacterial and viral infections unmask host factors in children at risk of asthma or whether they directly cause asthma remains unclear; both viewpoints could be justified, but the underlying mechanisms are complex and poorly understood. Recently, the role of the bacterial microbiome has been emphasised. But data are still sparse and future studies are needed for definitive conclusions to be made. In this Review, we discuss present knowledge of viruses and bacteria that infect and colonise the respiratory tract and mucosal surfaces, including their timepoint of action, host factors related to infection, and their effect on childhood asthma. Childhood asthma could be the result of a combination of altered host susceptibility and infectious agents.