Maternal food-avoidance diets and dietary supplements during breastfeeding.

AIMS: To identify maternal food-avoidance diets and dietary supplement use during breastfeeding, and to explore factors associated with food avoidance diets. DESIGN: A prospective mother-child birth cohort study. METHODS: Electronic questionnaires were answered by 1,462 breastfeeding mothers 6 months postpartum in the Preventing Atopic Dermatitis and Allergies in Children (PreventADALL) study from 2014-2016. Demographic and antenatal factors were analysed for associations with food avoidance diets in 1,368 women by multiple logistic regression. RESULTS: Overall, 289 breastfeeding women (19.8%) avoided at least one food item in their diet, most commonly cow's milk in 99 women (6.8%). Foods were most often avoided due to conditions in the child, maternal factors or lifestyle choice. The odds for food avoidance diets were 2.1 (95% CI: 1.3, 3.4) for food allergy (presumed or diagnosed) and 19.4 (5.4, 70.1) for celiac disease in the mother. Dietary supplements were reported by nearly 80%, most commonly cod liver oil.

Use of Swedish smokeless tobacco during pregnancy: A systematic review of pregnancy and early life health risk.

BACKGROUND AND AIMS: Smokeless tobacco is a heterogeneous product group with diverse composition and prevalence globally. Tobacco use during pregnancy is concerning due to the risk of adverse pregnancy outcomes and effects on child health. Nicotine may mediate several of these effects. This systematic review measured health outcomes from Swedish smokeless tobacco (snus) use during pregnancy. METHOD: Literature search was conducted by an information specialist in May 2022. We included human studies of snus use during pregnancy compared with no tobacco use, assessed risk of bias, conducted a meta-analysis and assessed confidence in effect-estimates using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). RESULTS: We included 18 cohort studies (42 to 1 006 398 participants). Snus use during pregnancy probably (moderate confidence in risk estimates) increase the risk of neonatal apnea, adjusted odds ratio 95% confidence interval [aOR (95% CI)] 1.96 (1.30 to 2.96). Snus use during pregnancy possibly (low confidence in risk estimates) increase the risk of stillbirths aOR 1.43 (1.02 to 1.99), extremely premature births aOR 1.69 (1.17 to 2.45), moderately premature birth aOR 1.26 (1.15 to 1.38), SGA aOR 1.26 (1.09 to 1.46), reduced birth weight mean difference of 72.47 g (110.58 g to 34.35 g reduction) and oral cleft malformations aOR 1.48 (1.00 to 2.21). It is uncertain (low confidence in risk estimates, CI crossing 1) whether snus use during pregnancy affects risk of preeclampsia aOR 1.11 (0.97 to 1.28), antenatal bleeding aOR 1.15 (0.92 to 1.44) and very premature birth aOR 1.26 (0.95 to 1.66). Risk of early neonatal mortality and altered heart rate variability is uncertain, very low confidence. Snus using mothers had increased prevalence of caesarean sections, low confidence. CONCLUSIONS: This systematic review reveals that use of smokeless tobacco (snus) during pregnancy may adversely impact the developing child.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper.

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

Early food intervention and skin emollients to prevent food allergy in young children (PreventADALL): a factorial, multicentre, cluster-randomised trial.

BACKGROUND: Primary prevention of food allergy by early introduction of allergenic foods seems promising. We aimed to determine whether early food introduction or the application of regular skin emollients in infants from a general population reduced the risk of food allergy. METHODS: This 2 × 2 factorial, cluster-randomised trial was done at Oslo University Hospital and Østfold Hospital Trust, Oslo, Norway, and Karolinska University Hospital, Stockholm, Sweden. Infants of women recruited antenatally at the routine 18-week ultrasound examination were cluster-randomised at birth to the following groups: (1) no intervention group; (2) the skin intervention group (skin emollients; bath additives and facial cream; from age 2 weeks to <9 months, both at least four times per week); (3) the food intervention group (early complementary feeding of peanut, cow's milk, wheat, and egg from age 3 months); or (4) combined intervention group (skin and food interventions). Participants were randomly assigned (1:1:1:1) using computer-generated randomisation based on clusters of 92 geographical areas and eight 3-month time blocks. Study personnel performing clinical assessments were masked to group allocation. The primary outcome was allergy to any interventional food at 36 months of age. The primary efficacy analysis was done by intention-to-treat analysis, which included all participants who were randomly assigned, apart from three individuals who withdrew their consent. This was a study performed within ORAACLE (the Oslo Research Group of Asthma and Allergy in Childhood; the Lung and Environment). This study is registered as ClinicalTrials.gov, NCT02449850. FINDINGS: We recruited 2697 women with 2701 pregnancies, from whom 2397 newborn infants were enrolled between April 14, 2015, and April 11, 2017. Of these infants, 597 were randomly assigned to the no intervention group, 575 to the skin intervention group, 642 to the food intervention group, and 583 to the combined intervention group. One participant in each of the no intervention, food intervention, and skin intervention groups withdrew consent and were therefore not included in any analyses. Food allergy was diagnosed in 44 children; 14 (2·3%) of 596 infants in the non-intervention group, 17 (3·0%) of 574 infants in the skin intervention group, six (0·9%) of 641 infants in the food intervention group, and seven (1·2%) of 583 infants in the combined intervention group. Peanut allergy was diagnosed in 32 children, egg allergy in 12 children, and milk allergy in four children. None had allergy to wheat. Prevalence of food allergy was reduced in the food intervention group compared with the no food intervention group (risk difference -1·6% [95% CI -2·7 to -0·5]; odds ratio [OR] 0·4 [95% CI 0·2 to 0·8]), but not compared with the skin intervention group (0·4% [95% CI -0·6 to 1· 5%]; OR 1·3 [0·7 to 2·3]), with no significant interaction effect (p=1·0). Preventing food allergy in one child required early exposure to allergenic foods in 63 children. No serious adverse events were observed. INTERPRETATION: Exposure to allergenic foods from 3 months of age reduced food allergy at 36 months in a general population. Our results support that early introduction of common allergenic foods is a safe and effective strategy to prevent food allergy. FUNDING: Full funding sources listed at end of paper (see Acknowledgments).

Extract and molecular-based early infant sensitization and associated factors-A PreventADALL study.

BACKGROUND: More knowledge about sensitization patterns in early infancy, including impact of molecular allergology, is needed to help predict future allergy development more accurately. OBJECTIVE: We aimed to determine the prevalence and patterns of allergic sensitization at 3 months of age, and explore possible associated factors. METHODS: From the Scandinavian antenatally recruited PreventADALL mother-child cohort, we included 1110 3-month infants with available serum. Sensitization was defined as s-IgE of ≥0.1 kUA /L by Phadiatop Infant® (ThermoFisher Scientific) including birch, cat, grass, dog, milk, egg, peanut and wheat. Further ImmunoCAP analyses to ovomucoid, casein, Ara h 1-3, omega-5-gliadin were performed in food extract s-IgE-positive children. Maternal sensitization was defined as s-IgE ≥ 0.35 kUA /L to Phadiatop® (inhalant allergen mix) and/or Fx5 (food allergen mix) at 18-week pregnancy. RESULTS: Overall 79 (7.3%) infants had specific sensitization, many with low s-IgE-levels (IQR 0.16-0.81 kUA /L), with 78 being sensitized to food extract allergens; 41 to egg, 27 to milk, 10 to peanut, and 25 to wheat. A total of 62/78 were further analysed, 18 (29%) had s-IgE to ovomucoid, casein, Ara h 1-3 and/or omega-5-gliadin. Eight infants (0.7%) were sensitized to inhalant allergens. Maternal sensitization to food allergens was associated with infant sensitization, odds ratio 3.64 (95% CI 1.53-8.68). CONCLUSION: Already at 3 months of age, 7% were sensitized to food, mostly without detectable s-IgE to food allergen molecules, and <1% to inhalant allergens. Maternal food sensitization was associated with infants' sensitization.

Fecal Microbiota Nutrient Utilization Potential Suggests Mucins as Drivers for Initial Gut Colonization of Mother-Child-Shared Bacteria.

The nutritional drivers for mother-child sharing of bacteria and the corresponding longitudinal trajectory of the infant gut microbiota development are not yet completely settled. We therefore aimed to characterize the mother-child sharing and the inferred nutritional utilization potential for the gut microbiota from a large unselected cohort. We analyzed in depth gut microbiota in 100 mother-child pairs enrolled antenatally from the general population-based Preventing Atopic Dermatitis and Allergies in Children (PreventADALL) cohort. Fecal samples collected at gestational week 18 for mothers and at birth (meconium), 3, 6, and 12 months for infants were analyzed by reduced metagenome sequencing to determine metagenome size and taxonomic composition. The nutrient utilization potential was determined based on the Virtual Metabolic Human (VMH, www.vmh.life) database. The estimated median metagenome size was ∼150 million base pairs (bp) for mothers and ∼20 million bp at birth for the children. Longitudinal analyses revealed mother-child sharing (P < 0.05, chi-square test) from birth up to 6 months for 3 prevalent Bacteroides species (prevalence, >25% for all age groups). In a multivariate analysis of variance (ANOVA), the mother-child-shared Bacteroides were associated with vaginal delivery (1.7% explained variance, P = 0.0001). Both vaginal delivery and mother-child sharing were associated with host-derived mucins as nutrient sources. The age-related increase in metagenome size corresponded to an increased diversity in nutrient utilization, with dietary polysaccharides as the main age-related factor. Our results support host-derived mucins as potential selection means for mother-child sharing of initial colonizers, while the age-related increase in diversity was associated with dietary polysaccharides.IMPORTANCE The initial bacterial colonization of human infants is crucial for lifelong health. Understanding the factors driving this colonization will therefore be of great importance. Here, we used a novel high-taxonomic-resolution approach to deduce the nutrient utilization potential of the infant gut microbiota in a large longitudinal mother-child cohort. We found mucins as potential selection means for the initial colonization of mother-child-shared bacteria, while the transition to a more adult-like microbiota was associated with dietary polysaccharide utilization potential. This knowledge will be important for a future understanding of the importance of diet in shaping the gut microbiota composition and development during infancy.

Physical activity in pregnancy: a Norwegian-Swedish mother-child birth cohort study.

BACKGROUND: Physical activity during pregnancy is important for maternal and offspring health. Optimal conditions during pregnancy may help reduce the burden of noncommunicable diseases. National and international guidelines recommend at least 150 minutes of physical activity of at least moderate intensity per week. To optimize physical activity in pregnant women, it is important to identify factors associated with higher levels of physical activity. OBJECTIVE: This study aimed to explore types and levels of physical activity in midpregnancy in Norway and Sweden and to identify factors associated with higher levels of physical activity. MATERIALS AND METHODS: From the population-based mother-child cohort Preventing Atopic Dermatitis and Allergies in Children study recruiting 2697 women in Norway and Sweden from 2014 to 2016, we included 2349 women who answered an electronic questionnaire at enrollment in midpregnancy. Women were asked about regular physical activity in the last 2 weeks of pregnancy and afterward for types and levels of physical activity in pregnancy and before pregnancy and socioeconomic status, lifestyle, and maternal health. Logistic regression analyses were used to identify factors associated with higher levels of physical activity in pregnancy, defined as >30 minutes per session of ≥2 times per week of moderate- or high-intensity brisk walking, strength training, jogging, and bicycling. RESULTS: No regular physical activity during the last 2 weeks before answering the questionnaire at midpregnancy was reported by 689 women (29%). In this study, 1787 women (76%) reported weekly strolling during pregnancy. Regular physical activity at least twice weekly in the first half of pregnancy was reported as brisk walking by 839 women (36%), bicycling by 361 women (15%), strength training by 322 women (14%), and other activities by <10% of women. Among the 1430 women with regular moderate- or high-intensity physical activity, the estimated median duration per week was 120 minutes. Higher physical activity levels were achieved in 553 women (23.5%) by brisk walking, 287 women (12.2%) by strength training, 263 women (11.2%) by bicycling, and 114 women (4.9%) by jogging. Higher physical activity levels were positively associated with regular physical activity before pregnancy, dog ownership, and atopic dermatitis and negatively associated with higher body mass index, study location in Østfold, previous pregnancy or pregnancies, non-Nordic origin, suburban living, and sick leave. CONCLUSION: At midpregnancy, 29% of women were inactive, and less than 50% of women had at least 2 hours of moderate-intensity physical activity weekly. Awareness of physical activity in pregnancy should be discussed at pregnancy follow-up visits, particularly among women with higher body mass index, sick leave, previous pregnancy or pregnancies, and non-Nordic origin.

Shared DNA methylation signatures in childhood allergy: The MeDALL study.

BACKGROUND: Differential DNA methylation associated with allergy might provide novel insights into the shared or unique etiology of asthma, rhinitis, and eczema. OBJECTIVE: We sought to identify DNA methylation profiles associated with childhood allergy. METHODS: Within the European Mechanisms of the Development of Allergy (MeDALL) consortium, we performed an epigenome-wide association study of whole blood DNA methylation by using a cross-sectional design. Allergy was defined as having symptoms from at least 1 allergic disease (asthma, rhinitis, or eczema) and positive serum-specific IgE to common aeroallergens. The discovery study included 219 case patients and 417 controls at age 4 years and 228 case patients and 593 controls at age 8 years from 3 birth cohorts, with replication analyses in 325 case patients and 1111 controls. We performed additional analyses on 21 replicated sites in 785 case patients and 2124 controls by allergic symptoms only from 8 cohorts, 3 of which were not previously included in analyses. RESULTS: We identified 80 differentially methylated CpG sites that showed a 1% to 3% methylation difference in the discovery phase, of which 21 (including 5 novel CpG sites) passed genome-wide significance after meta-analysis. All 21 CpG sites were also significantly differentially methylated with allergic symptoms and shared between asthma, rhinitis, and eczema. The 21 CpG sites mapped to relevant genes, including ACOT7, LMAN3, and CLDN23. All 21 CpG sties were differently methylated in asthma in isolated eosinophils, and 10 were replicated in respiratory epithelium. CONCLUSION: Reduced whole blood DNA methylation at 21 CpG sites was significantly associated with childhood allergy. The findings provide novel insights into the shared molecular mechanisms underlying asthma, rhinitis, and eczema.

De novo species identification using 16S rRNA gene nanopore sequencing.

Nanopore sequencing is rapidly becoming more popular for use in various microbiota-based applications. Major limitations of current approaches are that they do not enable de novo species identification and that they cannot be used to verify species assignments. This severely limits applicability of the nanopore sequencing technology in taxonomic applications. Here, we demonstrate the possibility of de novo species identification and verification using hexamer frequencies in combination with k-means clustering for nanopore sequencing data. The approach was tested on the human infant gut microbiota of 3-month-old infants. Using the hexamer k-means approach we identified two new low abundant species associated with vaginal delivery. In addition, we confirmed both the vaginal delivery association for two previously identified species and the overall high levels of bifidobacteria. Taxonomic assignments were further verified by mock community analyses. Therefore, we believe our de novo species identification approach will have widespread application in analyzing microbial communities in the future.

Butyrate Levels in the Transition from an Infant- to an Adult-Like Gut Microbiota Correlate with Bacterial Networks Associated with Eubacterium Rectale and Ruminococcus Gnavus.

Relatively little is known about the ecological forces shaping the gut microbiota composition during infancy. Therefore, the objective of the present study was to identify the nutrient utilization- and short-chain fatty acid (SCFA) production potential of gut microbes in infants during the first year of life. Stool samples were obtained from mothers at 18 weeks of pregnancy and from infants at birth (first stool) at 3, 6, and 12-months of age from the general population-based PreventADALL cohort. We identified the taxonomic and SCFA composition in 100 mother-child pairs. The SCFA production and substrate utilization potential of gut microbes were observed by multiomics (shotgun sequencing and proteomics) on six infants. We found a four-fold increase in relative butyrate levels from 6 to 12 months of infant age. The increase was correlated to Eubacterium rectale and its bacterial network, and Faecalibacterium prausnitzii relative abundance, while low butyrate at 12 months was correlated to Ruminococcus gnavus and its associated network of bacteria. Both E. rectale and F. prausnitzii expressed enzymes needed for butyrate production and enzymes related to dietary fiber degradation, while R. gnavus expressed mucus-, fucose, and human milk oligosaccharides (HMO)-related degradation enzymes. Therefore, we believe that the presence of E. rectale, its network, and F. prausnitzii are key bacteria in the transition from an infant- to an adult-like gut microbiota with respect to butyrate production. Our results indicate that the transition from an infant- to an adult-like gut microbiota with respect to butyrate producing bacteria, occurs between 6 and 12 months of infant age. The bacteria associated with the increased butyrate ratio/levels were E. rectale and F. prausnitzii, which potentially utilize a variety of dietary fibers based on the glycoside hydrolases (GHs) expressed. R. gnavus with a negative association to butyrate potentially utilizes mucin, fucose, and HMO components. This knowledge could have future importance in understanding how microbial metabolites can impact infant health and development.

Allergic disease and risk of stress in pregnant women: a PreventADALL study.

BACKGROUND: Maternal stress during pregnancy may negatively affect the health of mother and child. We therefore aimed to identify the proportion of women reporting high maternal stress in mid and late pregnancy and explore whether symptoms of maternal allergic disease are associated with perceived maternal stress in late pregnancy. METHOD: The population-based Preventing Atopic Dermatitis and Allergy in Children (PreventADALL) study enrolled 2697 pregnant women at their 18-week routine ultrasound examination in Norway and Sweden. Information about sociodemographic factors, symptoms and doctor-diagnosed asthma, allergic rhinitis, atopic dermatitis, food allergy, and anaphylaxis and stress using the 14-item perceived stress scale (PSS) was collected at 18 weeks (mid) and 34 weeks (late) pregnancy. High stress was defined as a PSS score ≥29. Scores were analysed using multivariate logistic and linear regression. RESULTS: Among the 2164 women with complete PSS data, 17% reported asthma, 20% atopic dermatitis, 23% allergic rhinitis, 12% food allergy and 2% anaphylaxis. The proportion of women reporting high stress decreased from 15% at mid to 13% at late pregnancy (p<0.01). The adjusted odds ratio for high stress in late pregnancy was 2.25 (95% CI 1.41-3.58) for self-reported symptoms of asthma, 1.46 (95% CI 1.02-2.10) for allergic rhinitis and 2.25 (95% CI 1.32-3.82) for food allergy. A multivariate linear regression model confirmed that symptoms of asthma (ß coefficient 2.11; 0.71-3.51), atopic dermatitis (ß coefficient 1.76; 0.62-2.89) and food allergy (ß coefficient 2.24; 0.63-3.84) were independently associated with increased PSS score. CONCLUSION: Allergic disease symptoms in pregnancy were associated with increased stress, highlighting the importance of optimal disease control in pregnancy.

Maternal use of nicotine products and breastfeeding 3 months postpartum.

AIM: We aimed to determine the prevalence of and factors associated with maternal use of nicotine products in relation to breastfeeding. METHODS: Nicotine use 3 months postpartum was determined in the Scandinavian PreventADALL mother-child birth cohort study recruiting 1837 women from 2014 to 2016. Electronic questionnaires at 18 weeks pregnancy and 3 months postpartum provided information on snus use, smoking or other nicotine use, infant feeding and socio-economic factors. The risk of nicotine use in relation to breastfeeding was analysed with logistic regression. RESULTS: Overall, 5.6% of women used snus (2.9%), smoked (2.7%) or both (n = 2) 3 months postpartum, while one used other nicotine products. Among the 1717 breastfeeding women, 95.1% reported no nicotine use, while 2.4% used snus, 2.5% smoked and one dual user. Compared to 3.7% nicotine use in exclusively breastfeeding women (n = 1242), the risk of nicotine use increased by partly (OR 2.26, 95% CI 1.45-3.52) and no breastfeeding (OR 4.58, 95% CI 2.57-8.21). Nicotine use before (14.5% snus, 16.4% smoking) or in pregnancy (0.2% snus, 0.4% smoking) significantly increased the risk of using nicotine during breastfeeding. CONCLUSION: Few breastfeeding women used snus or smoked 3 months postpartum, with increased risk by nicotine use before or during pregnancy.

Virus, allergic sensitisation and cortisol in infant bronchiolitis and risk of early asthma.

BACKGROUND: Acute bronchiolitis during infancy and human rhinovirus (HRV) lower respiratory tract infections increases the risk of asthma in atopic children. We aimed to explore whether specific viruses, allergic sensitisation or cortisol levels during acute bronchiolitis in infancy increase the risk of early asthma, using recurrent wheeze as a proxy. METHODS: In 294 children with a mean (range) age of 4.2 (0-12) months enrolled during hospitalisation for acute infant bronchiolitis, we analysed virus in nasopharyngeal aspirates, serum specific immunoglobulin E against food and inhalant allergens, and salivary morning cortisol. These factors were assessed by regression analyses, adjusted for age, sex and parental atopy, for risk of recurrent wheeze, defined as a minimum of three parentally reported episodes of wheeze at the 2-year follow-up investigation. RESULTS: At 2 years, children with, compared to without, recurrent wheeze had similar rates of respiratory syncytial virus (RSV) (82.9% versus 81.8%) and HRV (34.9% versus 35.0%) at the acute bronchiolitis, respectively. During infancy, 6.9% of children with and 9.2% of children without recurrent wheeze at 2 years were sensitised to at least one allergen (p=0.5). Neither recurrent wheeze nor incidence rate ratios for the number of wheeze episodes at 2 years were significantly associated with specific viruses, high viral load of RSV or HRV, allergic sensitisation, or morning salivary cortisol level during acute bronchiolitis in infancy. CONCLUSION: In children hospitalised with acute infant bronchiolitis, specific viruses, viral load, allergic sensitisation and salivary morning cortisol did not increase the risk of early asthma by 2 years of age.

Helicobacter pylori in early childhood and asthma in adolescence.

OBJECTIVE: An inverse effect of Helicobacter pylori (H. pylori) on the occurrence of asthma is debated and early acquisition of H. pylori may be important. We analyzed sera from 197 children from Environment and Childhood Asthma (ECA) study in Oslo for Helicobacter pylori (H. pylori) at 2 and 10 years, and symptoms and signs of asthma at 16 years of age. RESULTS: While 16.4% of children who were H. pylori negative at 2 and 10 years had current asthma at 16 years, none of the 12 children who were H. pylori positive at 2 years of age had asthma at the age of 16 years, regardless of H. pylori status at 10 years. This trend for less current asthma in children who were H. pylori positive at 2 years compared to persistent or transient negative status at 10 years was not statistically significant, probably due to low number of H. pylori positive children at 2 years of age. Acquisition of H. pylori in school age did not appear to influence the risk of current asthma. Much larger prospective studies are probably required to document whether or not early H. pylori infection may be involved in the risk of asthma development in later childhood.

Skin emollient and early complementary feeding to prevent infant atopic dermatitis (PreventADALL): a factorial, multicentre, cluster-randomised trial.

BACKGROUND: Skin emollients applied during early infancy could prevent atopic dermatitis, and early complementary food introduction might reduce food allergy in high-risk infants. The study aimed to determine if either regular skin emollients applied from 2 weeks of age, or early complementary feeding introduced between 12 and 16 weeks of age, reduced development of atopic dermatitis by age 12 months in the general infant population. METHODS: This population-based 2×2 factorial, randomised clinical trial was done at Oslo University Hospital and Østfold Hospital Trust, Oslo, Norway; and Karolinska University Hospital, Stockholm, Sweden. Infants of women recruited antenatally at the routine ultrasound pregnancy screening at 18 weeks were cluster-randomised at birth from 2015 to 2017 to the following groups: (1) controls with no specific advice on skin care while advised to follow national guidelines on infant nutrition (no intervention group); (2) skin emollients (bath additives and facial cream; skin intervention group); (3) early complementary feeding of peanut, cow's milk, wheat, and egg (food intervention group); or (4) combined skin and food interventions (combined intervention group). Participants were randomly assigned (1:1:1:1) using computer- generated cluster randomisation based on 92 geographical living area blocks as well as eight 3-month time blocks. Carers were instructed to apply the interventions on at least 4 days per week. Atopic dermatitis by age 12 months was the primary outcome, based on clinical investigations at 3, 6 and 12 months by investigators masked to group allocation. Atopic dermatitis was assessed after completing the 12-month investigations and diagnosed if either of the UK Working Party and Hanifin and Rajka (12 months only) diagnostic criteria were fulfilled. The primary efficacy analyses was done by intention-to-treat analysis on all randomly assigned participants. Food allergy results will be reported once all investigations at age 3 years are completed in 2020. This was a study performed within ORAACLE (the Oslo Research Group of Asthma and Allergy in Childhood; the Lung and Environment). The study is registered at clinicaltrials.gov, NCT02449850. FINDINGS: 2697 women were recruited between Dec 9, 2014, and Oct 31, 2016, from whom 2397 newborn infants were enrolled from April 14, 2015, to April 11, 2017. Atopic dermatitis was observed in 48 (8%) of 596 infants in the no intervention group, 64 (11%) of 575 in the skin intervention group, 58 (9%) of 642 in the food intervention group, and 31 (5%) of 583 in the combined intervention group. Neither skin emollients nor early complementary feeding reduced development of atopic dermatitis, with a risk difference of 3·1% (95% CI -0·3 to 6·5) for skin intervention and 1·0% (-2·1 to 4·1) for food intervention, in favour of control. No safety concerns with the interventions were identified. Reported skin symptoms and signs (including itching, oedema, exanthema, dry skin, and urticaria) were no more frequent in the skin, food, and combined intervention groups than in the no intervention group. INTERPRETATION: Neither early skin emollients nor early complementary feeding reduced development of atopic dermatitis by age 12 months. Our study does not support the use of these interventions to prevent atopic dermatitis by 12 months of age in infants. FUNDING: The study was funded by several public and private funding bodies: The Regional Health Board South East, The Norwegian Research Council, Health and Rehabilitation Norway, The Foundation for Healthcare and Allergy Research in Sweden-Vårdalstiftelsen, Swedish Asthma and Allergy Association's Research Foundation, Swedish Research Council-the Initiative for Clinical Therapy Research, The Swedish Heart-Lung Foundation, SFO-V at the Karolinska Institute, Freemason Child House Foundation in Stockholm, Swedish Research Council for Health, Working Life and Welfare-FORTE, Oslo University Hospital, the University of Oslo, and Østfold Hospital Trust.

Predicting Skin Barrier Dysfunction and Atopic Dermatitis in Early Infancy.

BACKGROUND: Dry skin is associated with increased transepidermal water loss (TEWL), which has been found to precede atopic dermatitis (AD) in childhood. OBJECTIVE: We aimed to identify parental, prenatal, and perinatal predictive factors of dry skin, high TEWL, and AD at 3 months of age, and to determine if dry skin or high TEWL at 3 months can predict AD at 6 months. METHODS: From the Preventing Atopic Dermatitis and Allergies in children prospective birth cohort study, we included 1150 mother-child pairs. Dry skin, TEWL, and eczema were assessed at 3- and 6-month investigations. Eczema, used as a proxy for AD, was defined as the presence of eczematous lesions, excluding differential diagnoses to AD. High TEWL was defined as TEWL >90th percentile, equaling 11.3 g/m2/h. Potential predictive factors were recorded from electronic questionnaires at 18- and 34-week pregnancy and obstetric charts. RESULTS: Significant predictive factors (P < .05) for dry skin at 3 months were delivery >38 gestational weeks and paternal age >37 years; for high TEWL, male sex, birth during winter season, and maternal allergic disease; and for eczema, elective caesarean section, multiparity, and maternal allergic diseases. Dry skin without eczema at 3 months was predictive for eczema at 6 months (adjusted odds ratio: 1.92, 95% confidence interval: 1.21-3.05; P = .005), whereas high TEWL at 3 months was not. CONCLUSION: In early infancy, distinct parental- and pregnancy-related factors were predictive for dry skin, high TEWL, and AD. Dry skin at 3 months of age was predictive for AD 3 months later.

Snus in pregnancy and infant birth size: a mother-child birth cohort study.

RATIONALE: While recent studies show that maternal use of snus during pregnancy is increasing, the potential effects on infant birth size is less investigated, with conflicting results. OBJECTIVES: We aimed to determine if maternal use of snus during pregnancy influences the infant anthropometric and proportional size measures at birth. METHODS: In 2313 mother-child pairs from the population-based, mother-child birth cohort PreventADALL (Preventing Atopic Dermatitis and ALLergies) in Norway and Sweden, we assessed nicotine exposure by electronic questionnaire(s) at 18 and 34 weeks of pregnancy, and anthropometric measurements at birth. Associations between snus exposure and birth size outcomes were analysed by general linear regression. RESULTS: Birthweight was not significantly different in infants exposed to snus in general, and up to 18 weeks of pregnancy in particular, when adjusting for relevant confounders including maternal age, gestational age at birth, pre-pregnancy body mass index, parity, fetal sex and maternal gestational weight gain up to 18 weeks. We found no significant effect of snus use on the other anthropometric or proportional size measures in multivariable linear regression models. Most women stopped snus use in early pregnancy. CONCLUSION: Exposure to snus use in early pregnancy, with most women stopping when knowing about their pregnancy, was not associated with birth size. We were unable to conclude on effects of continued snus use during pregnancy because of lack of exposure in our cohort.