Pregnancy exposures and risk of childhood asthma admission in a population birth cohort

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.

The impact of maternal asthma on the fetal lung: Outcomes, mechanisms and interventions

Maternal asthma affects up to 17% of pregnancies and is associated with adverse infant, childhood, and adult respiratory outcomes, including increased risks of neonatal respiratory distress syndrome, childhood wheeze and asthma. In addition to genetics, these poor outcomes are likely due to the mediating influence of maternal asthma on the in-utero environment, altering fetal lung and immune development and predisposing the offspring to later lung disease. Maternal asthma may impair glucocorticoid signalling in the fetus, a process critical for lung maturation, and increase fetal exposure to proinflammatory cytokines. Therefore, interventions to control maternal asthma, increase glucocorticoid signalling in the fetal lung, or Vitamin A, C, and D supplementation to improve alveologenesis and surfactant production may be beneficial for later lung function. This review highlights potential mechanisms underlying maternal asthma and offspring respiratory morbidities and describes how pregnancy interventions can promote optimal fetal lung development in babies of asthmatic mothers.

Gestational hypertension and risk of atopic diseases in offspring, a national-wide cohort study

INTRODUCTION

Gestational hypertension can lead to complications, such as preeclampsia. Preeclampsia is one of leading causes of perinatal morbidity and mortality. Abnormal placentation, immune dysregulation, and maternal inflammatory response are possible etiologies. The burden of atopic diseases is increasing worldwide. Prenatal exposure might play a role in the pathogenesis of these two diseases. The aim of this study was to evaluate the association between gestational hypertension and atopic diseases from a nationwide perspective.

MATERIAL AND METHODS

The primary data were retrieved from Taiwan's National Health Insurance Research Database. The Maternal and Child Health Database was used to generate links between mothers and children. From 2004 to 2019, mothers with a diagnosis of gestational hypertension were identified as cases. The control groups were matched to the cases by maternal age, neonatal gender, date of birth, at a control-to-case ratio of 4:1. Each child was reviewed to confirm the diagnosis of atopic disease. Covariates including both maternal and neonatal factors were also collected.

RESULTS

A total of 1,935,874 primiparas were enrolled in this study. After excluding 16,851 mothers with a history of hypertension, a total of 1,919,023 offspring were included in the study for the period 2004-2019. Gestational hypertension was associated with asthma (HR, 1.12, 95% CI, 1.02-1.23) and atopic dermatitis (HR, 1.10, 95% CI, 1.00-1.21) in offspring after controlling for cofactors. Nevertheless, gestational hypertension did not play an independent factor for allergic rhinitis (HR, 1.02, 95% CI, 0.95-1.10) or urticaria (HR, 1.02, 95% CI, 0.91-1.15).

CONCLUSION

Maternal gestational hypertension increases the cumulative risk for asthma and atopic dermatitis in offspring.

Antibiotics in pregnancy influence nasal microbiome and respiratory morbidity in infancy

Background

The effects of prenatal antibiotic exposure on respiratory morbidity in infancy and the involved mechanisms are still poorly understood. We aimed to examine whether prenatal antibiotic exposure in the third trimester is associated with nasal microbiome and respiratory morbidity in infancy and at school age, and whether this association with respiratory morbidity is mediated by the nasal microbiome.

Methods

We performed 16S ribosomal RNA gene sequencing (regions V3-V4) on nasal swabs obtained from 296 healthy term infants from the prospective Basel-Bern birth cohort (BILD) at age 4-6 weeks. Information about antibiotic exposure was derived from birth records and standardised interviews. Respiratory symptoms were assessed by weekly telephone interviews in the first year of life and a clinical visit at age 6 years. Structural equation modelling was used to test direct and indirect associations accounting for known risk factors.

Results

α-Diversity indices were lower in infants with antibiotic exposure compared to nonexposed infants (e.g. Shannon index p-value 0.006). Prenatal antibiotic exposure was also associated with a higher risk of any, as well as severe, respiratory symptoms in the first year of life (risk ratio 1.38, 95% CI 1.03-1.84; adjusted p-value (padj)=0.032 and risk ratio 1.75, 95% CI 1.02-2.97; padj=0.041, respectively), but not with wheeze or atopy in childhood. However, we found no indirect mediating effect of nasal microbiome explaining these clinical symptoms.

Conclusion

Prenatal antibiotic exposure was associated with lower diversity of nasal microbiome in infancy and, independently of microbiome, with respiratory morbidity in infancy, but not with symptoms later in life.

Risk Factors Affecting Development and Persistence of Preschool Wheezing: Consensus Document of the Emilia-Romagna Asthma (ERA) Study Group

Wheezing at preschool age (i.e., before the age of six) is common, occurring in about 30% of children before the age of three. In terms of health care burden, preschool children with wheeze show double the rate of access to the emergency department and five times the rate of hospital admissions compared with school-age asthmatics. The consensus document aims to analyse the underlying mechanisms involved in the pathogenesis of preschool wheezing and define the risk factors (i.e., allergy, atopy, infection, bronchiolitis, genetics, indoor and outdoor pollution, tobacco smoke exposure, obesity, prematurity) and the protective factors (i.e., probiotics, breastfeeding, vitamin D, influenza vaccination, non-specific immunomodulators) associated with the development of the disease in the young child. A multidisciplinary panel of experts from the Emilia-Romagna Region, Italy, addressed twelve key questions regarding managing preschool wheezing. Clinical questions have been formulated by the expert panel using the PICO format (Patients, Intervention, Comparison, Outcomes). Systematic reviews have been conducted on PubMed to answer these specific questions and formulate recommendations. The GRADE approach has been used for each selected paper to assess the quality of the evidence and the degree of recommendations. Based on a panel of experts and extensive updated literature, this consensus document provides insight into the pathogenesis, risk and protective factors associated with the development and persistence of preschool wheezing. Undoubtedly, more research is needed to improve our understanding of the disease and confirm the associations between certain factors and the risk of wheezing in early life. In addition, preventive strategies must be promoted to avoid children's exposure to risk factors that may permanently affect respiratory health.

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 of juvenile idiopathic arthritis with maternal infection: a case control study

OBJECTIVE

Maternal infection has been posited as a risk factor for childhood autoimmune disease such as type I diabetes. Given that similar studies in JIA are scant, our objective was to evaluate the association between Juvenile Idiopathic Arthritis (JIA) and maternal infection.

METHODS

This case-control study used an existing database that included 1290 JIA cases and 6072 controls matched on birth year. Maternal infection information was obtained from Washington State birth records. JIA diagnosis and categories were confirmed through chart review. Logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

JIA was not associated with maternal infection (OR = 1.02, 95%CI: 0.8-1.3). There was no association between JIA and maternal infection for persistent oligoarticular, RF negative polyarticular, or enthesitis-related JIA. There was suggestive evidence of an increased association of maternal infection with JIA in females in sex-stratified analysis.

CONCLUSIONS

We did not observe an increased risk of JIA in children exposed to maternal infection. Suggestive evidence of differential sex-specific results warrants further study.

The effect of maternal SARS-CoV-2 infection timing on birth outcomes: a retrospective multicentre cohort study

BACKGROUND

The impact of maternal SARS-CoV-2 infection remains unclear. In this study, we evaluated the risk of maternal SARS-CoV-2 infection on birth outcomes and how this is modulated by the pregnancy trimester in which the infection occurs. We also developed models to predict gestational age at delivery for people following a SARS-CoV-2 infection during pregnancy.

METHODS

We did a retrospective cohort study of the impact of maternal SARS-CoV-2 infection on birth outcomes. We used clinical data from Providence St Joseph Health electronic health records for pregnant people who delivered in the USA at the Providence, Swedish, or Kadlec sites in Alaska, California, Montana, Oregon, or Washington. The SARS-CoV-2 positive cohort included people who had a positive SARS-CoV-2 PCR-based test during pregnancy, subdivided by trimester of infection. No one in this cohort had been vaccinated for COVID-19 at time of infection. The SARS-CoV-2 negative cohort were people with at least one negative SARS-CoV-2 PCR-based test and no positive tests during pregnancy. Cohorts were matched on common covariates impacting birth outcomes, and univariate and multivariate analysis were done to investigate risk factors and predict outcomes. The primary outcome was gestational age at delivery with annotation of preterm birth classification. We trained multiple supervised learning models on 24 features of the SARS-CoV-2 positive cohort to evaluate performance and feature importance for each model and discuss the impact of SARS-CoV-2 infection on gestational age at delivery.

FINDINGS

Between March 5, 2020, and July 4, 2021, 73 666 pregnant people delivered, 18 335 of whom had at least one SARS-CoV-2 test during pregnancy before Feb 14, 2021. We observed 882 people infected with SARS-CoV-2 during their pregnancy (first trimester n=85; second trimester n=226; and third trimester n=571) and 19 769 people who have never tested positive for SARS-CoV-2 and received at least one negative SARS-CoV-2 test during their pregnancy. SARS-CoV-2 infection indicated an increased risk of preterm delivery (p<0·05) and stillbirth (p<0·05), accounted for primarily by first and second trimester SARS-CoV-2 infections. Gestational age at SARS-CoV-2 infection was correlated with gestational age at delivery (p<0·01) and had the greatest impact on predicting gestational age at delivery. The people in this study had mild or moderate SARS-CoV-2 infections and acute COVID-19 severity was not correlated with gestational age at delivery (p=0·31).

INTERPRETATION

These results suggest that pregnant people would benefit from increased monitoring and enhanced prenatal care after first or second trimester SARS-CoV-2 infection, regardless of acute COVID-19 severity.

FUNDING

US National Institutes of Health.

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.

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

Introduction

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

Materials and methods

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

Results

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

Conclusion

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

Association between hypertensive disorders of pregnancy and the risk of asthma, eczema and allergies in offspring: A systematic review and meta-analysis

OBJECTIVE

Conduct a systematic review and meta-analysis examining the association between hypertensive disorders of pregnancy (HDP) and risk of asthma, eczema, food allergies and allergic rhinitis in the offspring.

DESIGN

A systematic review and random-effects meta-analyses were used to synthesize the published literature. PRISMA guidelines were followed throughout. Two independent reviewers carried out data extraction and quality assessment of included studies. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess certainty of findings.

DATA SOURCES

A systematic search of PubMed, Embase, Web of Science and CINAHL was performed from inception of databases-21 April 2020, supplemented by hand-searching reference lists of included articles.

ELIGIBILITY CRITERIA

Two reviewers independently reviewed titles, abstracts and full-text articles. English language, cohort, case-control and cross-sectional published studies examining the association between HDP (primary exposure: pre-eclampsia; secondary exposures: all other HDP) and asthma, eczema, food allergies and allergic rhinitis were included.

RESULTS

Of the 2833 studies retrieved, 14 studies met inclusion criteria. Of these, 11 studies reported evidence of association between HDP and atopic disorders. Thirteen studies reported estimates for asthma. Seven of these included adjusted estimates (including 3 645 773 participants) for a pre-eclampsia-asthma relationship resulting in a pooled odds ratio (OR) of 1.14 (95% CI: 1.04, 1.26) (I²  = 62%). However, this OR was reduced to 1.08 (95% CI: (0.78, 1.48) when the large registry-based cohort studies were excluded, and only studies using parent-reported measures to determine a diagnosis of asthma were included. Four studies included adjusted estimates (including 254 998 participants) for other HDP and asthma (pooled OR: 1.02, 95% CI: 0.96, 1.09) (I²  = 0%). Two studies provided adjusted estimates (including 1 699 663 participants) for a pre-eclampsia-eczema relationship (pooled OR: 1.06, 95% CI: 0.98, 1.14) (I²  = 0%). One study including pre-eclampsia-food allergies was identified (OR: 1.28, 95% CI: 1.11, 1.46). Three studies examined a HDP (including pre-eclampsia) and allergic rhinitis relationship, with effect estimates ranging from 1.14 to 2.10. Studies were classified as low or low-moderate risk of bias, while GRADE certainty of findings were low to very low.

CONCLUSIONS

While pre-eclampsia was associated with a possible increased risk of asthma in offspring, there was no evidence for a relationship between other HDP and asthma. There is a lack of published literature examining the association between HDP and eczema, food allergy and allergic rhinitis. Further primary research is warranted to gain a better understanding of the association between HDP and the risk of childhood atopic disease.

SYSTEMATIC REVIEW REGISTRATION

Review protocol in appendix.

Maternal urinary tract infection during pregnancy and long-term infectious morbidity of the offspring

BACKGROUND

Urinary tract infection (UTI) is a common bacterial infection in pregnant women and is associated with adverse perinatal outcomes. We sought to investigate the long-term infectious outcomes of children to mothers who were diagnosed with UTI during their pregnancy.

METHODS

A population-based cohort analysis was conducted at a single tertiary medical center. The study included all singleton deliveries between the years 1991-2014, comparing offspring born to mothers diagnosed with UTI during their pregnancy with those born to non-exposed mothers. Infectious-related hospitalizations of the offspring up to the age of 18 years were assessed according to a predefined set of ICD-9 codes. A Kaplan-Meier survival curve was conducted to compare cumulative hospitalization incidence between the groups. A Cox regression model was used to adjust for confounders.

RESULTS

During the study period, 243,725 deliveries met the inclusion criteria. Of them, 8034 (3.3%) were exposed to maternal UTI during pregnancy. Infectious-related hospitalizations were significantly prevalent in offspring to exposed mothers (12.3% vs. 11.0%, OR = 1.125, 95% CI 1.051-1.204, Kaplan-Meier log rank p < 0.001). In the Cox regression model, while controlling for clinically relevant confounders, maternal UTI (adjuster HR = 1.240), as well as preterm delivery (adjusted HR = 1.385) and cesarean delivery (adjusted HR = 1.198) were noted as independent risk factors for long-term infectious morbidity of the offspring.

CONCLUSIONS

Maternal UTI in pregnancy may influence offspring susceptibility to pediatric infections, as it was found to be an independent risk factor for long-term infectious morbidity of the offspring.

Trimester-specific association between antibiotics exposure during pregnancy and childhood asthma or wheeze: the role of confounding

PURPOSE

We conducted the meta-analysis to respectively evaluate the risk of prenatal antibiotics use during specific trimesters (first, second, and third trimester) on childhood asthma or wheeze and to explore whether the association was biased by potential confounding.

METHODS

The quality of included articles was assessed according to Newcastle-Ottawa Quality Assessment Scale and the Strengthening the Reporting of Observational Studies in Epidemiology. A random effects model was used to calculate pooled risk ratios and corresponding 95% confidence interval (CI), and publication bias was tested by Egger statistical test.

RESULTS

Eight studies were included finally. We found a crude positive association of prenatal antibiotics use during each pregnancy trimester and risk of childhood asthma or wheeze with RRs of 1.28 (95% CI, 1.09-1.51) for the first trimester of pregnancy, 1.25 (95% CI, 1.02-1.52) for the second trimester, and 1.25 (95% CI, 1.05-1.49) for the third trimester. However, when considering potential factors of maternal infections and presence of siblings, the relationship for each trimester was insignificant.

CONCLUSIONS

This systemic review and meta-analysis proposed a crude positive association between prenatal antibiotic use in every specific trimester and risk of childhood asthma or wheeze. However, adjustment for confounders decreased the relative risk estimates, supporting the concept that these associations are, at least in part, because of confounding by indication.

Prenatal maternal depression related to allergic rhinoconjunctivitis in the first 5 years of life in children of the EDEN mother-child cohort study

Backgroud: Evidence about the relationship between prenatal maternal depression and the development of childhood asthma and allergies in early life is scarce. We aimed to examine this relationship by using data set of EDEN mother-child cohort study. A total of 1139 children were followed-up until the age of 5 years.

METHODS

Prenatal maternal depression was self-reported by using the Centre for Epidemiological Studies-Depression scale (CES-D) questionnaire and was classified into binary variable (maternal depression [CES-D score of ≥16] and no maternal depression [CES-D score of <16]). Asthma and allergies in the first 5 years were assessed by using the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC). Adjusted odds ratio (aOR) was estimated for the relationship between prenatal maternal depression and early life asthma and allergies by marginal models through the method of generalized estimating equation (GEE) when adjusting for the confounders.

RESULTS

In our study population, 13.67 % of the mothers had clinical significant depression (the total scores for CES-D ≥16) during pregnancy. For children ages 5 years, the prevalence of wheezing, physician-diagnosed asthma, physician-diagnosed eczema and allergic rhinoconjunctivitis were 46.78, 20.99, 29.17, and 22.54%, respectively. Prenatal maternal depression was associated with ever allergic rhinoconjunctivitis (aOR 1.87 [95% confidence interval {CI}, 1.33-2.62]). No significant relationships were found between prenatal maternal depression and wheezing, physician-diagnosed asthma and physician-diagnosed eczema (aOR 1.12 [95% CI, 0.91-1.39], aOR 1.23 [95% CI, 0.81-1.85] and aOR 1.17 [95% CI, 0.86-1.61], respecitvely).

CONCLUSION

Prenatal maternal depression was related to ever allergic rhinoconjunctivitis in the first 5 years of life in children of EDEN mother-child cohort study.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Air Pollution During Pregnancy and Cord Blood Immune System Biomarkers

OBJECTIVES

We aimed to determine whether average and trimester-specific exposures to ambient measures of nitrogen dioxide (NO2) and particular matter (PM2.5) were associated with elevated cord blood concentrations of immunoglobulin E (IgE) and two epithelial cell produced cytokines: interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP).

METHODS

This study utilized data and biospecimens from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study. There were 2001 pregnant women recruited between 2008 and 2011 from 10 Canadian cities. Maternal exposure to NO2 and PM2.5 was estimated using land use regression and satellite-derived models.

RESULTS

We observed statistically significant associations between maternal NO2 exposure and elevated cord blood concentrations of both IL-33 and TSLP among girls but not boys.

CONCLUSIONS

Maternal NO2 exposure may impact the development of the newborn immune system as measured by cord blood concentrations of two cytokines.

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.

Prenatal triclosan exposure and cord blood immune system biomarkers

Triclosan is widely used as an antimicrobial agent and preservative that has been hypothesized to play a role in asthma and allergic disease. The limited body of literature regarding the allergenicity of triclosan has not evaluated prenatal exposure and subsequent potential effects on the developing immune system. The objective of the present study was to determine the association between prenatal urinary triclosan concentrations and cord blood immune system biomarker concentrations. Umbilical cord blood samples were obtained from the Maternal-Infant Research on Environmental Chemicals (MIREC) Biobank and were tested for three immune system biomarkers: immunoglobulin E (IgE), thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33). Triclosan concentrations were measured in urine at 6-13 weeks gestation. No statistically significant associations were observed between prenatal triclosan concentrations and elevated concentrations of any immune system biomarker (n=1219 participants). Longitudinal studies are necessary to determine how the observed findings at birth translate into childhood.

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.

Association Between Neonatal Urinary Tract Infection and Risk of Childhood Allergic Rhinitis

The current population-based study investigated the onset of neonatal urinary tract infection (UTI) and the associated risks of allergic rhinitis. From 2000 to 2005, 3285 children with neonatal UTI and 13,128 randomly selected controls were enrolled from the National Health Insurance Research Database in Taiwan and frequency matched by gender, urbanization of residential area, parental occupation, and baseline year. We compared the risk of allergic rhinitis between the non-UTI and UTI cohorts by performing multivariable Cox regression analysis. We observed a significant relationship between UTI and allergic rhinitis. This study examined 16,413 patients, among whom 3285 had UTI and 13,128 did not have UTI. The overall incidence rate ratio of allergic rhinitis was 1.41-fold higher in the UTI cohort than in the non-UTI cohort (100.2 vs 70.93 per 1000 person-y). After potential risk factors were adjusted for, the adjusted hazard ratio of allergic rhinitis was 1.32 (95% confidence interval = 1.23-1.41). Regardless of gender, the UTI cohort had a higher risk of allergic rhinitis than that of the non-UTI cohort. The patients with UTI in different follow-up durations were equally susceptible to developing allergic rhinitis compared with those without UTI, especially in follow-up durations shorter than 5 years. Patients with UTI and particular comorbidities such as infections and neonatal jaundice had a significantly increased risk of allergic rhinitis. UTI in newborns is significantly associated with the development of allergic rhinitis in childhood and might be a risk factor for subsequent childhood allergic rhinitis.

Maternal exposure to metals and persistent pollutants and cord blood immune system biomarkers

BACKGROUND

The fetal time period is a critical window of immune system development and resulting heightened susceptibility to the adverse effects of environmental exposures. Epidemiologists and toxicologists have hypothesized that persistent organic pollutants, pesticides and metals have immunotoxic properties. Immunotoxic effects may manifest as an altered immune system profile at birth. Immunoglobulin E, thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33) may be implicated in the etiology of childhood allergy and are detectable at birth. The objective of this study was to examine the potential relationship between maternal concentrations of metals, persistent organic pollutants, and pesticides and elevated umbilical cord blood concentrations of IgE, TSLP, and IL-33 in a Canadian birth cohort.

METHODS

This study utilized data collected in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada cohort study of 2,001 pregnant women. Of these women, 1258 had a singleton, term birth and cord blood sample. Logistic regression was used to determine associations between log-transformed continuous variables and immune system biomarkers.

RESULTS

Inverse relationships were observed between lead, DDE, PCB-118, and a summary index of organophosphorous metabolites and jointly elevated concentrations of IL-33 and TSLP. None of the environmental contaminants were associated with increased odds of a high cord blood immune system biomarker concentration.

CONCLUSIONS

In this primarily urban Canadian population of pregnant women and their newborns, maternal blood or urine concentrations of persistent organic pollutants, pesticides, and metals were not associated with immunotoxic effects that manifest as increased odds of elevated concentrations of IgE, TSLP or IL-33.

Neonatal urinary tract infection may increase the risk of childhood asthma

The aim of this population-based retrospective cohort study was to investigate the onset of urinary tract infection in newborns and the associated risks of childhood asthma. Children with neonatal UTI (n = 3,312) and randomly selected controls (n = 13,243) were enrolled for our analysis. We calculated the follow-up person-years for each participant from the index date until the diagnosis of asthma, the end of 2008, or withdrawal from the insurance system (because of death or loss to follow-up). Furthermore, we compared the risk of asthma between non-UTI and UTI cohorts by using Cox proportional hazards model analysis, the adjusted hazard ratio (aHR), and a 95 % confidence interval (95 % CI). The overall asthma incidence rate was found to be 1.53-fold significantly higher in the UTI cohort than in the non-UTI cohort (70.3 vs 45.8 per 1000 person-years). After we adjusted for potential risk factors, the overall risk of asthma remained higher in the UTI cohort (aHR = 1.47, 95 % CI = 1.35-1.59). The incidence rate was higher in boys than in girls. Overall, patients suffering from UTI may have a greater risk of developing asthma than patients without UTI. This nationwide retrospective cohort study demonstrates that neonatal UTI may increase the risk of childhood asthma.

Urinary tract infections in pregnancy: old and new unresolved diagnostic and therapeutic problems

Urinary tract infections (UTIs) are common in pregnant women and pose a great therapeutic challenge, since the risk of serious complications in both the mother and her child is high. Pregnancy is a state associated with physiological, structural and functional urinary tract changes which promote ascending infections from the urethra. Unlike the general population, all pregnant women should be screened for bacteriuria with urine culture, and asymptomatic bacteriuria must be treated in every case that is diagnosed, as it is an important risk factor for pyelonephritis in this population. The antibiotic chosen should have a good maternal and fetal safety profile. In this paper, current principles of diagnosis and management of UTI in pregnancy are reviewed, and the main problems and controversies are identified and discussed.

Maternal socioeconomic status and the risk of asthma among offspring

BACKGROUND

To evaluate the association between maternal socioeconomic status (SES) during pregnancy and asthma among offspring.

METHODS

A retrospective observational hospital-based birth cohort study in a university-based Obstetrics and Gynecology department in Finland. A total of 40 118 women with singleton live births between 1989 and 2007 were linked with data from the register for asthma medication for their offspring (n = 2518). Pregnancy and maternal SES factors were recorded during pregnancy and labor. SES was categorized thus: upper white-collar workers (highest SES), lower white-collar workers, blue-collar workers, others (lowest SES) and cases with missing information. Logistic regression analysis was used to determine the association between maternal SES and childhood asthma.

RESULTS

We found no convincing evidence of a direct association between maternal SES and childhood asthma. Parental smoking was the clearest factor affecting asthma among children of lower white-collar workers. Differences in pregnancy and delivery characteristics were observed between the SES groups.

CONCLUSIONS

Maternal socioeconomic status had no significant direct impact on the prevalence of asthma in this Finnish birth cohort. Finnish public health services appeared to offer equal quality services independently of SES.

TRIAL REGISTRATION

The study is registered in Kuopio University Hospital register (TUTKI): ID 5302448 .

Urbanization factors associated with childhood asthma and prematurity: a population-based analysis aged from 0 to 5 years in Taiwan by using Cox regression within a hospital cluster model

OBJECTIVE

Childhood asthma and premature birth are both common; however, no studies have reported urbanization association between asthma and prematurity and the duration of prematurity affect asthma development. We use Taiwan Longitudinal Health Insurance Database (LHID) to explore association between asthma and prematurity among children by using a population-based analysis.

METHODS

This is a retrospective cohort study with registration data derived from Taiwan LHID. We evaluated prematurely born infants and children aged <5 years (n = 532) and age-matched control patients (n = 60505) using Cox proportional hazard regression analysis within a hospital cluster model. Of the 61 037 examinees, 14 012 experienced asthma during the 5-year follow-up, including 161 (72.26 per 1000 person-years) infants and children born prematurely and 13 851 (40.27 per 1000 person-years) controls.

RESULTS

The hazard ratio for asthma during 5-year follow-up period was 1.95 (95% confidence interval = 1.67-2.28) among children born prematurely. Boys born prematurely aged 0-2 years were associated with higher asthma rates compared with girls in non-premature and premature groups. Living in urban areas, those born prematurely were associated with higher rates of asthma compared with non-prematurity. Those born prematurely lived in northern region had higher asthma hazard ratio than other regions.

CONCLUSION

Our analyses indicated that sex, age, urbanization level, and geographic region are significantly associated with prematurity and asthma. Based on cumulative asthma-free survival curve generated using the Kaplan-Meier method, infants born prematurely should be closely monitored to see if they would develop asthma until the age of 6 years.

An association between autumn birth and clozapine treatment in patients with schizophrenia: a population-based analysis

BACKGROUND

Numerous studies on seasonality of birth and schizophrenia risk have been published but it is uncertain whether, among those with schizophrenia, refractory illness exhibits any predilection for birth month. We hypothesized and examined whether a season of birth effect was present in patients with schizophrenia with a history of clozapine treatment.

METHOD

Using record linkage with Danish registers, we examined patients with schizophrenia born between 1950 and 1970, and between 1995 and 2009 and Cox regression analysis was used to examine season of birth in relation to history of clozapine treatment.

RESULTS

In a study population corresponding to 60,062 person-years from 5328 individuals with schizophrenia of which 1223 (23%) received at least one clozapine prescription, birth in the autumn (September-November) was associated with clozapine treatment (HR = 1.24; 95% CI 1.07-1.46) when compared with birth in the spring (March-May).

CONCLUSION

Although replication studies are needed, this is the first evidence from a nationwide study suggesting a possible season-associated risk of clozapine treatment in schizophrenia. The reasons for this relationship remain to be further investigated but might be partially explained by early exposures such as winter flu season and low vitamin D levels.

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.

The association of preterm birth with severe asthma and atopic dermatitis: a national cohort study

BACKGROUND

Asthma and atopic dermatitis are both regarded as atopic diseases. Being born too early is associated with increased risk of asthma, but some studies have indicated that the opposite might be true for atopic dermatitis. We explored in more detail the associations between preterm birth, asthma, and atopic dermatitis.

METHODS

We analyzed data from Norwegian registries with prospectively collected data. All live births in Norway from 1967 through 2001 were followed through 2005 by linking the Medical Birth Registry of Norway to the National Insurance Scheme and to Statistics Norway. Only severe asthma and atopic dermatitis were registered in the National Insurance Scheme.

RESULTS

Of a total of 1,760,821 children, we identified 9,349 cases (0.5%) with severe asthma and 6,930 cases (0.4%) with severe atopic dermatitis. Compared with children born at term (37-41 wk gestation), preterm birth was associated with increased odds for severe asthma (odds ratio (OR) 1.7 (95% confidence interval (CI): 1.6-1.8) for 32-36 wk gestation and OR 3.6 (95% CI: 3.1-4.2) for 23-31 wk) and decreased odds for severe atopic dermatitis (OR 0.9 (95% CI: 0.8-1.0) for 32-36 wk gestation and OR 0.7 (95% CI: 0.5-1.0) for 23-31 wk). Adjustment for perinatal and socio-demographic factors weakened the association between gestational age and severe asthma, while slightly strengthening the association between gestational age and severe atopic dermatitis.

CONCLUSIONS

Preterm birth was associated with increased risk of severe asthma and decreased risk of severe atopic dermatitis.

Gestational age, birth weight, and risk of respiratory hospital admission in childhood

OBJECTIVE

To investigate the risk of emergency respiratory hospital admission during childhood associated with gestational age at birth and growth restriction in utero.

METHODS

The study included a total population electronic birth cohort with anonymized record-linkage of multiple health and administrative data sets. Participants were 318,613 children born in Wales, United Kingdom, between May 1, 1998, and December 31, 2008. The main outcome measure was emergency respiratory hospital admissions.

RESULTS

The rate of admission in the first year of life ranged from 41.5 per 100 child-years for infants born before 33 weeks' gestation to 9.8 per 100 child-years for infants born at 40 to 42 weeks' gestation. The risk of any emergency respiratory admission up to age 5 years increased as gestational age decreased to <40 weeks. Even at 39 weeks' gestation, there was an increased risk of emergency hospital admissions for respiratory conditions compared with infants born at 40 to 42 weeks (adjusted hazard ratio 1.10; 95% confidence interval 1.08-1.13). Small for gestational age (<10th centile for gestation and gender-specific birth weight) was independently associated with an increased risk of any emergency respiratory admission to hospital (adjusted hazard ratio 1.07; 95% confidence interval 1.04-1.10).

CONCLUSIONS

The risk of emergency respiratory admission up to age 5 years decreased with each successive week in gestation up to 40 to 42 weeks. Although the magnitude of increased risk associated with moderate and late preterm births is small, the number of infants affected is large and therefore presents a significant impact on health care services.

Vitamin D in asthma and future perspectives

Humans have the ability to synthesize vitamin D during the action of ultraviolet (UV) radiation upon the skin. Apart from the regulation of calcium and phosphate metabolism, another critical role for vitamin D in immunity and respiratory health has been revealed, since vitamin D receptors have also been found in other body cells. The term "vitamin D insufficiency" has been used to describe low levels of serum 25-hydroxyvitamin D that may be associated with a wide range of pulmonary diseases, including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. This review focuses on the controversial relationship between vitamin D and asthma. Also, it has been found that different gene polymorphisms of the vitamin D receptor have variable associations with asthma. Other studies investigated the vitamin D receptor signaling pathway in vitro or in experimental animal models and showed either a beneficial or a negative effect of vitamin D in asthma. Furthermore, a range of epidemiological studies has also suggested that vitamin D insufficiency is associated with low lung function. In the future, clinical trials in different asthmatic groups, such as infants, children of school age, and ethnic minorities are needed to establish the role of vitamin D supplementation to prevent and/or treat asthma.

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.

Maternal allergy is associated with surface-bound IgE on cord blood basophils

BACKGROUND

The cell type(s) mediating the maternal influence on allergic disease in children remain unclear. We set out to define the relationship between maternal allergy and frequencies of cord blood (CB) basophils, and plasmacytoid dendritic cells (pDCs); to characterize surface-bound IgE and FcεRI expressions on these cells; and to investigate the association between maternal and CB serum IgE levels with surface-bound IgE and FcεRI expressions.

METHODS

One hundred and three mother/infant dyads were recruited prenatally, and maternal allergic history was recorded. Maternal blood was collected prior to delivery, and CB was collected after birth. Flow cytometry was used to identify CB basophils and pDCs and to determine surface-bound IgE and FcεRI expressions.

RESULTS

Frequencies of CB basophils and pDCs were low and not related to maternal history of allergy. Percentages of CB basophils with surface-bound IgE were significantly higher in infants of allergic mothers compared with infants of non-allergic mothers (median, 59.60% vs. 19.70%, p = 0.01). IgE on CB basophils correlated with CB IgE levels (r = 0.72, p < 0.0001), but not with maternal IgE levels (r = 0.26, p = 0.06). IgE on CB pDCs was low and not significantly associated with maternal or CB IgE levels. Similarly, FcεRI expression by CB basophils and pDCs was not significantly associated with maternal or CB IgE levels.

CONCLUSIONS

Frequencies of CB basophils and pDCs are not influenced by maternal allergy. CB basophils and pDCs have surface-bound IgE and express FcεRI; however, only IgE on CB basophils appears influenced by maternal allergy.

The case of drug causation of childhood asthma: antibiotics and paracetamol

AIM

The rising prevalence of bronchial asthma has led to world-wide efforts to understand and stem this development. Cross-sectional studies appear to show that early childhood use of antibiotics may be an important contributory factor, with paracetamol as an additional suspected cause. However, mounting evidence, which is reviewed here, points to various confounding factors as the major reasons for these reported associations.

METHODS

PubMed and EMBASE were systematically searched for studies on associations between antibiotics and/or paracetamol with asthma and/or wheezing, published up to November 2012. A total of 64 pertinent studies were identified, 35 focusing on antibiotics, 19 on paracetamol, and ten addressing both antibiotics and paracetamol, bringing the number of relevant datasets to 74.

RESULTS

Numerous studies were cross-sectional and made no adjustment for the indication of antibiotics or paracetamol; consequently, they were unable to dismiss possible confounding by indication. Where such adjustments could be performed (mostly in longitudinal studies), they substantially weakened or entirely eliminated the association with asthma or asthma surrogates present in the unadjusted data.

CONCLUSION

The weight of evidence of the collected studies in our review strongly suggests that the association of antibiotics with childhood asthma reflects various forms of bias, the most prominent of which is confounding by indication. Recent studies and meta-analyses support the same conclusion for paracetamol. Truly indicated antibiotics should not be withheld from infants or young children for fears they might develop asthma. Likewise, there is no sound reason to replace paracetamol as the preferred pain relief and fever medication in this age group.

In utero exposure to antidepressants and the use of drugs for pulmonary diseases in children

Purpose

The use of antidepressants during pregnancy is common. Some studies suggest an association between in utero exposure to antidepressants and the occurrence of pulmonary diseases like asthma later in life. Serotonin reuptake inhibitors (SSRIs) as well tricyclic antidepressants (TCAs) are thought to be involved in the development of the respiratory rhythm generator (RRG) and the maturation of the formation of surfactant. In this study the use of drugs for pulmonary diseases in children who were exposed to antidepressants in utero were compared with non-exposed children.

Methods

The pharmacy prescription database IADB.nl was used for a cohort study in which the use of drugs for pulmonary disease in children after in utero exposure to antidepressants (TCAs, SSRIs) was compared with children with no antidepressant exposure in utero. Drugs for pulmonary diseases were applied as a proxy for disturbed development of the respiratory tract.

Results

A small though significant increase in the incidence risk ratio (IRR) of the use of drugs for pulmonary disease was found after any-time in utero exposure to SSRIs, adjusted for maternal use of antibiotics, of 1.17 (95 % CI 1.16–1.18). An increase was also seen when we looked specifically for the use of SSRIs in at least the first trimester (IRR = 1.18, 95 % CI 1.17–1.20). An increased IRR in the use of drugs for pulmonary disease was also seen when children were exposed to TCAs, but this was not statistically significant. However, in both groups our sample size was rather small. The effect size is modest and may also be confounded by maternal smoking.

Conclusions

In utero exposure to SSRIs leads to a statistically significant increase in the use of drugs for pulmonary diseases, especially when exposure occurred during the first trimester of pregnancy. The increase in the use of drugs for pulmonary disease may also be related to other factors. Therefore, further study is recommended.

Vitamin D, the placenta and pregnancy

Impaired vitamin D status is common to many populations around the world. However, data suggest that this is a particular problem for specific groups such as pregnant women. This has raised important questions concerning the physiological and clinical impact of low vitamin D levels during pregnancy, with implications for classical skeletal functions of vitamin D, as well as its diverse non-classical actions. The current review will discuss this with specific emphasis on the classical calciotropic effects of vitamin D as well as the less well established immunological functions of vitamin D that may influence pregnancy outcome. The review also describes the pathways that are required for metabolism and function of vitamin D, and the various clinical complications that have been linked to impaired vitamin D status during pregnancy.