Early diet of preterm infants and development of allergic or atopic disease: randomised prospective study

Early-Life Nutrition in Preterm Infants and Risk of Respiratory Infections and Wheezing: A Scoping Review

INTRODUCTION

Preterm birth is a common early-life event that can lead to long-term consequences. The incidence of wheezing, asthma, and respiratory tract infections is higher in children born prematurely than in the general population. The purpose of this review was to synthesize the existing literature on the role of early-life nutrition in the later risk of respiratory morbidities.

METHODS

A scoping review of the literature was performed by searching three online databases. Inclusion criteria were: infants born <37 GWk, comparing human milk versus any other type of milk feeding formulation. Our primary outcomes were wheezing or asthma or respiratory tract infections after discharge. Two authors independently screened the results and extracted study characteristics using a predefined charting form.

RESULTS

Nine articles were included (eight cohort studies and one randomized trial). Four studies supported the protective effect of breastfeeding on wheezing or respiratory infections or both. Four studies did not confirm this association. One study confirmed the protective role of breastfeeding only on the subgroup of girls. There was a high heterogeneity among the included studies, in the type of milk feeding, outcomes, and age at follow-up.

CONCLUSIONS

The current evidence is conflicting. The high heterogeneity and methodological flaws could have influenced the results of the studies. Carefully designed studies are required to define the role of early-life nutrition among preterm infants on their long-term respiratory outcomes.

Potential Biomarkers, Risk Factors and their Associations with IgE-mediated Food Allergy in Early Life: A Narrative Review

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for food allergy include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers which predict the risk of developing food allergy in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy and synthesizes the currently available data indicating potential biomarkers. While there is a large body of research evidence available within each field of potential risk factors, there are very limited number of studies which span multiple methodological fields, for example including immunology, microbiome, genetic/epigenetic factors and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge confirmed food allergy in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high quality, reliable and reproducible research findings.

STATEMENT OF SIGNIFICANCE

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. Identifying reliable biomarkers which predict the risk of developing food allergy would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. This review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy. This helps in identifying reliable biomarkers to predict the risk of developing food allergy, which could be valuable in both preventing morbidity and mortality and by making interventions available at the earliest opportunity.

Complementary Feeding: Recommendations for the Introduction of Allergenic Foods and Gluten in the Preterm Infant

BACKGROUND

The aim of this systematic review is to analyze the available literature on the introduction of allergenic foods and gluten among preterm infants.

METHODS

A systematic review of published studies concerning the introduction of gluten and allergenic foods in preterm infants was performed on PubMed and on the Cochrane Library.

RESULTS

Of the 174 PubMed results, 15 papers were considered suitable for the review. A total of 83 records were identified through the Cochrane Library search; eight papers were included in the review. Additional papers were identified from the reference lists of included studies. A secondary search was conducted on the same databases to find recommendations and advice regarding healthy full-term infants that could be translated to preterm infants. Therefore, 59 additional papers were included in the review.

CONCLUSIONS

Current guidelines for the introduction of solid food cannot be directly transposed to preterm infants. Further research is needed to provide evidence-based guidelines regarding weaning in preterm infants. To date, we can suggest that in preterm infants allergenic foods and gluten may be introduced when complementary feeding is started, any time after 4 months of corrected age, avoiding delayed introduction and irrespective of infants' relative risk of developing allergy. Avoiding large amounts of gluten during the first few weeks after gluten introduction and during infancy is advised, despite limited evidence to support this recommendation.

EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update)

BACKGROUND

This guideline from the European Academy of Allergy and Clinical Immunology (EAACI) recommends approaches to prevent the development of immediate-onset / IgE-mediated food allergy in infants and young children. It is an update of a 2014 EAACI guideline.

METHODS

The guideline was developed using the AGREE II framework and the GRADE approach. An international Task Force with representatives from 11 countries and different disciplinary and clinical backgrounds systematically reviewed research and considered expert opinion. Recommendations were created by weighing up benefits and harms, considering the certainty of evidence and examining values, preferences and resource implications. The guideline was peer-reviewed by external experts, and feedback was incorporated from public consultation.

RESULTS

All of the recommendations about preventing food allergy relate to infants (up to 1 year) and young children (up to 5 years), regardless of risk of allergy. There was insufficient evidence about preventing food allergy in other age groups. The EAACI Task Force suggests avoiding the use of regular cow's milk formula as supplementary feed for breastfed infants in the first week of life. The EAACI Task Force suggests introducing well-cooked, but not raw egg or uncooked pasteurized, egg into the infant diet as part of complementary feeding. In populations where there is a high prevalence of peanut allergy, the EAACI Task Force suggests introducing peanuts in an age-appropriate form as part of complementary feeding. According to the studies, it appears that the most effective age to introduce egg and peanut is from four to 6 months of life. The EAACI Task Force suggests against the following for preventing food allergy: (i) avoiding dietary food allergens during pregnancy or breastfeeding; and (ii) using soy protein formula in the first 6 months of life as a means of preventing food allergy. There is no recommendation for or against the following: use of vitamin supplements, fish oil, prebiotics, probiotics or synbiotics in pregnancy, when breastfeeding or in infancy; altering the duration of exclusive breastfeeding; and hydrolysed infant formulas, regular cow's milk-based infant formula after a week of age or use of emollients.

CONCLUSIONS

Key changes from the 2014 guideline include suggesting (i) the introduction of peanut and well-cooked egg as part of complementary feeding (moderate certainty of evidence) and (ii) avoiding supplementation with regular cow's milk formula in the first week of life (low certainty of evidence). There remains uncertainty in how to prevent food allergy, and further well-powered, multinational research using robust diagnostic criteria is needed.

Breastfeeding and Allergic Diseases: What's New?

Asthma and other allergic disorders, such as atopic dermatitis and food allergies, are common chronic health problems in childhood. The rapid rise in the prevalence of these conditions registered over the last few decades has stressed the need to identify the modifiable risk factors associated with the development of these diseases. Breast milk, recognized as the gold standard for healthy growth and development of the newborn, is one of the major factors associated with a lower incidence of allergic and infectious diseases in childhood and young adulthood. Although the underlying mechanisms for these effects are not well understood, breastfeeding leads to immune system maturation. In this narrative review, we summarize existing evidence on breastfeeding and human milk composition in relation to allergic disease prevention or development.

Allergy prevention through breastfeeding

PURPOSE OF REVIEW

To perform a nonsystematic review of the literature on the role of breastfeeding as primary prevention tool for allergic diseases.

RECENT FINDINGS

Human milk contains vast amounts of biologically active components that have a significant impact on the development of the gut microbiota. Exclusively breastfed infants show a different microbiota, with a predominance of Bifidobacterium species in their intestines.The mechanisms underlying the antiallergic effects of human milk are most probably complex, as human milk contains not only nutritional substances but also functional molecules including polysaccharides, cytokines, proteins, and other components which can produce an epigenetic modulation of the innate and adaptive immune responses of the infant in very early life.

SUMMARY

Currently, there is not sufficient strong evidence to guarantee its effectiveness in allergy prevention and therefore the main international scientific societies still do not count it among the recognized primary prevention strategies of allergy.

Preventing food allergy in infancy and childhood: Systematic review of randomised controlled trials

BACKGROUND

This systematic review of ways to prevent immediate-onset/IgE-mediated food allergy will inform guidelines by the European Academy of Allergy and Immunology (EAACI).

METHODS

The GRADE approach was used. Eleven databases were searched from 1946 to October 2019 for randomized controlled trials (and large prospective cohort studies in the case of breastfeeding). The studies included heterogeneous interventions, populations, and outcomes and so were summarized narratively.

RESULTS

Forty-six studies examined interventions to reduce the risk of food allergy in infancy (up to 1 year) or early childhood. The following interventions for pregnant or breastfeeding women and/or infants may have little to no effect on preventing food allergy, but the evidence is very uncertain: dietary avoidance of food allergens, vitamin supplements, fish oil, probiotics, prebiotics, synbiotics, and emollients. Breastfeeding, hydrolyzed formulas, and avoiding cow's milk formula may not reduce the risk of cow's milk protein allergy; however, temporary supplementation with cow's milk formula in the first week of life may increase the risk of cow's milk allergy. Introducing well-cooked egg, but not pasteurized raw egg, from 4 to 6 months probably reduces the risk of hen's egg allergy. Introducing regular peanut consumption into the diet of an infant at increased risk beginning from 4 to 11 months probably results in a large reduction in peanut allergy in countries with a high prevalence. These conclusions about introducing peanut are based on moderate certainty evidence, from single trials in high-income countries.

CONCLUSIONS

Sixty percent of the included studies were published in the last 10 years, but much still remains to be understood about preventing food allergy. In particular, there is a need to validate the potential benefits of early introduction of food allergens in a wider range of populations.

Free Amino Acids in Human Milk: A Potential Role for Glutamine and Glutamate in the Protection Against Neonatal Allergies and Infections

Breastfeeding is indicated to support neonatal immune development and to protect against neonatal infections and allergies. Human milk composition is widely studied in relation to these unique abilities, which has led to the identification of various immunomodulating components in human milk, including various bioactive proteins. In addition to proteins, human milk contains free amino acids (FAAs), which have not been well-studied. Of those, the FAAs glutamate and glutamine are by far the most abundant. Levels of these FAAs in human milk sharply increase during the first months of lactation, in contrast to most other FAAs. These unique dynamics are globally consistent, suggesting that their levels in human milk are tightly regulated throughout lactation and, consequently, that they might have specific roles in the developing neonate. Interestingly, free glutamine and glutamate are reported to exhibit immunomodulating capacities, indicating that these FAAs could contribute to neonatal immune development and to the unique protective effects of breastfeeding. This review describes the current understanding of the FAA composition in human milk. Moreover, it provides an overview of the effects of free glutamine and glutamate on immune parameters relevant for allergic sensitization and infections in early life. The data reviewed provide rationale to study the role of free glutamine and glutamate in human milk in the protection against neonatal allergies and infections.

Preterm Infants Fed Cow's Milk-Derived Fortifier Had Adverse Outcomes Despite a Base Diet of Only Mother's Own Milk

Objective: An increasingly common practice is to feed preterm infants a base diet comprising only human milk (HM), usually fortified with a cow's milk (CM)-derived fortifier (CMDF). We evaluated the safety of CMDF in a diet of 100% mother's own milk (MOM) against a HM-derived fortifier (HMDF). To date, this has received little research attention. Study Design: We reanalyzed a 12-center randomized trial, originally comparing exclusive HM feeding, including MOM, donor milk (DM), and HMDF, versus a CM exposed group fed MOM, preterm formula (PTF), and CMDF1. However, for the current study, we performed a subgroup analysis (n = 114) selecting only infants receiving 100% MOM base diet plus fortification, and fed no DM or PTF. This allowed for an isolated comparison of fortifier type: CMDF versus HMDF to evaluate the primary outcomes: necrotizing enterocolitis (NEC) and a severe morbidity index of NEC surgery or death; and several secondary outcomes. Results: CMDF and HMDF groups had similar baseline characteristics. CMDF was associated with higher risk of NEC; relative risk (RR) 4.2 (p = 0.038), NEC surgery or death (RR 5.1, p = 0.014); and reduced head circumference gain (p = 0.04). Conclusions: In neonates fed, as currently recommended with a MOM-based diet, the safety of CMDF when compared to HMDF has been little researched. We conclude that available evidence points to an increase in adverse outcomes with CMDF, including NEC and severe morbidity comprising NEC surgery or death.

Fortification of Human Milk for Preterm Infants: Update and Recommendations of the European Milk Bank Association (EMBA) Working Group on Human Milk Fortification

Evidence indicates that human milk (HM) is the best form of nutrition uniquely suited not only to term but also to preterm infants conferring health benefits in both the short and long-term. However, HM does not provide sufficient nutrition for the very low birth weight (VLBW) infant when fed at the usual feeding volumes leading to slow growth with the risk of neurocognitive impairment and other poor health outcomes such as retinopathy and bronchopulmonary dysplasia. HM should be supplemented (fortified) with the nutrients in short supply, particularly with protein, calcium, and phosphate to meet the high requirements of this group of babies. In this paper the European Milk Bank Association (EMBA) Working Group on HM Fortification discusses the existing evidence in this field, gives an overview of different fortification approaches and definitions, outlines the gaps in knowledge and gives recommendations for practice and suggestions for future research. EMBA recognizes that "Standard Fortification," which is currently the most utilized regimen in neonatal intensive care units, still falls short in supplying sufficient protein for some VLBW infants. EMBA encourages the use of "Individualized Fortification" to optimize nutrient intake. "Adjustable Fortification" and "Targeted Fortification" are 2 methods of individualized fortification. The quality and source of human milk fortifiers constitute another important topic. There is work looking at human milk derived fortifiers, but it is still too early to draw precise conclusions about their use. The pros and cons are discussed in this Commentary in addition to the evidence around use of fortifiers post discharge.

Improved lung function at age 6 in children born very preterm and fed extra protein post-discharge

BACKGROUND

In very preterm-born children, alveolar maturation is challenged and lung function is often compromised during childhood. So far, very few studies have focused on type of early nutrition and lung function in children born preterm.

METHODS

This study is a 6 years follow-up of 281 very preterm-born infants (VPI) with a gestational age (GA) <32 + 0 weeks. Infants breastfed at discharge from hospital were randomized to unfortified (UHM) or fortified (FHM) mother's (human) milk, whereas those not breastfed received a preterm formula (PF). The intervention lasted until 4 months corrected age. At 6 years of age fractional exhaled nitric oxide (FeNO), airway resistance and occlusion measurements with reversibility were performed. Data on predisposition to asthma and allergy as well as possible allergic symptoms of the child were obtained with questionnaires.

RESULTS

Outcome data was fully or partially available on 160 (66.9%) of 239 children. This included 49 (30.6%) children fed UHM, 58 (36.3%) fed FHM and 53 (33.1%) fed PF. Successful FeNO measurements were obtained in 119 (74.4%) children and airway resistance measurements in 160. FeNO results were not significantly different between feeding groups. Children fed a protein-enriched diet (FMH/PF) had the lowest, for example, best, airway resistance; FHM-fed had lower values than UHM-fed (P = 0.042) before, and PF-fed had significantly lower values than UHM-fed after beta-2-agonist inhalation (P = 0.050). The tendency of lower airway resistance when protein enriched were the same in gender-specific analyses. In SGA children, the same tendency was found between PF- and UHM-fed (P = 0.007 before and P = 0.046 after beta-2-agonist inhalation). All values were within reference limits.

CONCLUSIONS

Lung function in very preterm-born children may improve when fed a protein-enriched nutrition post-discharge.

Cytokines and Soluble Receptors in Breast Milk as Enhancers of Oral Tolerance Development

The postpartum period is an important window during which environmental factors can shape the life-long health of the infant. This time period often coincides with substantial milk consumption either in the form of breast milk or from cow's milk sources, such as infant formulas. Although breast milk is the most beneficial source of nutrients for infants during the first 6 months after birth, its role in regulating food allergy development, through regulation of oral tolerance, is still controversial. Breast milk contains several factors that can impact mucosal immune function, including immune cells, antibodies, microbiota, oligosaccharides, cytokines, and soluble receptors. However, there is considerable variation in the assessed levels of cytokines and soluble receptors between studies and across the lactation period. Most of these cytokines and soluble receptors are absent, or only found in limited quantities, in commercial baby formulas. Differences in content of these pluripotent factors, which impact on both the mother and the neonate, could contribute to the controversy surrounding the role of breast milk regulating oral tolerance. This review highlights current knowledge about the importance of cytokines and soluble receptors in breast milk on the development of oral tolerance and tolerance-relateddisorders. Understanding the mechanisms by which such milk components might promote oral tolerance could aid in the development of improved strategies for allergy prevention.

The Association of the Delayed Introduction of Cow's Milk with IgE-Mediated Cow's Milk Allergies

BACKGROUND

Although exclusive breastfeeding at least 4 to 6 months has been recommended to prevent IgE-mediated cow's milk allergy (IgE-CMA), early introduction of food allergens has received a lot of attention in recent years for the prevention of food allergies.

OBJECTIVES

We aimed to determine whether IgE-CMA is associated with a feeding pattern in early infancy.

METHODS

In a case-control study, we retrospectively compared the patient background, past history of atopic dermatitis, bronchial asthma, family history of allergic diseases, feeding patterns in early infancy, and the reason for choosing early infancy feeding patterns of patients with IgE-CMA with age- and sex-matched healthy controls using a questionnaire completed by their mothers. To minimize the influence of confounders, we also compared patients with IgE-CMA with those with IgE-mediated egg allergy (IgE-EA).

RESULTS

A total of 51 patients with IgE-CMA were compared with 102 controls (1:2 matching) and 32 unmatched patients with IgE-EA. In a multivariable logistic regression analysis, the adjusted odds ratio of delayed (started more than 1 month after birth) or no regular cow's milk formula (less than once daily) was 23.74 (95% CI, 5.39-104.52) comparing the CMA group with the Control group, and 10.16 (95% CI, 2.48-41.64) comparing the CMA group with the EA group. Only 3 (6.5%), 2 (4.8%), and 3 (14.3%) mothers in the CMA group, the Control group, and the EA group chose "To prevent allergic disease" as a reason for choosing exclusive or almost exclusive breastfeeding in the first month of life, respectively.

CONCLUSIONS

The early introduction of cow's milk formula is associated with lower incidence of IgE-CMA.

Human Milk and Allergic Diseases: An Unsolved Puzzle

There is conflicting evidence on the protective role of breastfeeding in relation to the development of allergic sensitisation and allergic disease. Studies vary in methodology and definition of outcomes, which lead to considerable heterogeneity. Human milk composition varies both within and between individuals, which may partially explain conflicting data. It is known that human milk composition is very complex and contains variable levels of immune active molecules, oligosaccharides, metabolites, vitamins and other nutrients and microbial content. Existing evidence suggests that modulation of human breast milk composition has potential for preventing allergic diseases in early life. In this review, we discuss associations between breastfeeding/human milk composition and allergy development.

The Skin as a Route of Allergen Exposure: Part II. Allergens and Role of the Microbiome and Environmental Exposures

PURPOSE OF REVIEW

This second part of the article aims to highlight recent contributions in the literature that enhance our understanding of the cutaneous immune response to allergen.

RECENT FINDINGS

Several properties of allergens facilitate barrier disruption and cutaneous sensitization. There is a strong epidemiologic relationship between the microbiome, both the gut and skin, and atopic dermatitis (AD). The mechanisms connecting these two entities remain enigmatic; however, recent murine models show that commensal skin bacteria play an active role in supporting skin barrier homeostasis and defense against microbial penetration. Likewise, the association between the lack of colonization with Staph species and AD development suggests a potentially functional role for these organisms in regulating the skin barrier and response to environmental allergens. In undisrupted skin, evidence suggests that the cutaneous route may promote allergen tolerance. Properties of environmental allergens and commensal bacteria add to the complex landscape of skin immunity. Further investigation is needed to elucidate how these properties regulate the cutaneous immune response to allergen.

Clinical and nutritional outcomes of two liquid human milk fortifiers for premature infants

BACKGROUND

In preterm infants fortification of human milk with human milk fortifiers (HMF) to optimize nutrition and growth is standard practice. We compared clinical, nutrition and growth outcomes in infants receiving two types of liquid HMF (LHMF).

METHODS

Clinical, nutrition and growth outcomes were compared between infants admitted to a level IV NICU, and born with birth weight less than or equal to 1800 grams, between 10/1/2014-12/31/2014 and received human milk with acidified LHMF (ALHMF) and between 1/1/2015-4/31/2015 and received human milk with heat treated LHMF (HTLHMF).

RESULTS

Of the 85 qualifying infants, 67 received human milk and LHMF. ALHMF group had significantly higher incidence of metabolic acidosis and lower bicarbonate and base excess levels relative to infants receiving HTLHMF (P < 0.001). There were no significant differences by LHMF status in other clinical outcomes and nutrition and growth outcomes. In multivariate analyses, ALHMF use was associated with metabolic acidosis, and lower base excess and bicarbonate levels.

CONCLUSION

In our study, the clinical, nutrition and growth outcomes between the two LHMF groups were similar. However, use of ALHMF in preterm infants was associated with increased incidence of metabolic acidosis in our cohort. Further randomized control trials are warranted to evaluate these findings.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Prevention of food and airway allergy: consensus of the Italian Society of Preventive and Social Paediatrics, the Italian Society of Paediatric Allergy and Immunology, and Italian Society of Pediatrics

BACKGROUND

Allergic sensitization in children and allergic diseases arising therefrom are increasing for decades. Several interventions, functional foods, pro- and prebiotics, vitamins are proposed for the prevention of allergies and they can't be uncritically adopted.

OBJECTIVE

This Consensus document was developed by the Italian Society of Preventive and Social Paediatrics and the Italian Society of Paediatric Allergy and Immunology. The aim is to provide updated recommendations regarding allergy prevention in children.

METHODS

The document has been issued by a multidisciplinary expert panel and it is intended to be mainly directed to primary care paediatricians. It includes 19 questions which have been preliminarily considered relevant by the panel. Relatively to each question, a literature search has been performed, according to the Italian National Guideline Program. Methodology, and a brief summary of the available literature data, has been provided. Many topics have been analyzed including the role of mother's diet restriction, use of breast/formula/hydrolyzed milk; timing of introduction of complementary foods, role (if any) of probiotics, prebiotics, vitamins, exposure to dust mites, animals and to tobacco smoke.

RESULTS

Some preventive interventions have a strong level of recommendation. (e.g., the dehumidifier to reduce exposure to mite allergens). With regard to other types of intervention, such as the use of partially and extensively hydrolyzed formulas, the document underlines the lack of evidence of effectiveness. No preventive effect of dietary supplementation with polyunsaturated fatty acids, vitamins or minerals has been demonstrated. There is no preventive effect of probiotics on asthma, rhinitis and allergic diseases. It has demonstrated a modest effect, but steady, in the prevention of atopic dermatitis.

CONCLUSIONS

The recommendations of the Consensus are based on a careful analysis of the evidence available. The lack of evidence of efficacy does not necessarily imply that some interventions may not be effective, but currently they can't be recommended.

Breastfeeding is associated with reduced childhood hospitalization: evidence from a Scottish Birth Cohort (1997-2009)

OBJECTIVE

To evaluate the risk of childhood hospitalization associated with infant feeding patterns at 6-8 weeks of age in Scotland.

STUDY DESIGN

A retrospective population level study based on the linkage of birth, death, maternity, infant health, child health surveillance, and admission records for children born as single births in Scotland between 1997 and 2009 (n = 502 948) followed up to March 2012. Descriptive analyses, Kaplan Meier tests, and Cox regression were used to quantify the association between the mode of infant feeding and risk of childhood hospitalization for respiratory, gastrointestinal, and urinary tract infections, and other common childhood ailments during the study period.

RESULTS

Within the first 6 months of life, there was a greater hazard ratio (HR) of hospitalization for common childhood illnesses among formula-fed infants (HR 1.40; 95% CI 1.35-1.45) and mixed-fed infants (HR 1.18; 95% CI 1.11-1.25) compared with infants exclusively breastfed after adjustment for parental, maternal, and infant health characteristics. Within the first year of life and beyond, a greater relative risk of hospitalization was observed among formula-fed infants for a range of individual illnesses reported in childhood including gastrointestinal, respiratory, and urinary tract infections, otitis media, fever, asthma, diabetes, and dental caries.

CONCLUSIONS

Using linked administrative data, we found greater risks of hospitalization in early childhood for a range of common childhood illnesses among Scottish infants who were not exclusively breastfed at 6-8 weeks of age.

Infant feeding practices and reported food allergies at 6 years of age

OBJECTIVE

The goal of this study was to identify the frequency of physician-diagnosed food allergies among 6-year-old US children and study the impact of exclusive breastfeeding and complementary food introduction on this frequency.

METHODS

Data were analyzed from children who participated in the Infant Feeding Practices Study II Year 6 Follow-Up Study (Y6FU). Children with probable food allergy (pFA) were defined as children with report of physician-diagnosed food allergy at age 6 years. Subgroups of pFA included children who were not diagnosed before 1 year of age (new pFA) and those with atopic risk factors (high risk).

RESULTS

Prevalence of total pFA in the Y6FU was 6.34%. The majority of these children had new pFA and high-risk factors. Higher maternal education, higher family income, family history of food allergy, and reported eczema before 1 year of age were significantly associated with higher odds of total or new pFA. Exclusive breastfeeding duration and timing of complementary food introduction were not significantly associated with total pFA. However, exclusive breastfeeding of ≥4 months compared with no breastfeeding was marginally associated with lower odds of new pFA (adjusted odds ratio: 0.51; P = .07); this effect was not observed with high-risk children.

CONCLUSIONS

Analysis of infant and maternal variables in the Y6FU cohort of US children revealed that socioeconomic and atopic factors were the main predictors of pFA at age 6 years. Exclusive breastfeeding of ≥4 months may have a preventive effect on development of pFA after 1 year of age in non high-risk children.

EAACI food allergy and anaphylaxis guidelines. Primary prevention of food allergy

Food allergy can have significant effects on morbidity and quality of life and can be costly in terms of medical visits and treatments. There is therefore considerable interest in generating efficient approaches that may reduce the risk of developing food allergy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Prevention and is part of the EAACI Guidelines for Food Allergy and Anaphylaxis. It aims to provide evidence-based recommendations for primary prevention of food allergy. A wide range of antenatal, perinatal, neonatal, and childhood strategies were identified and their effectiveness assessed and synthesized in a systematic review. Based on this evidence, families can be provided with evidence-based advice about preventing food allergy, particularly for infants at high risk for development of allergic disease. The advice for all mothers includes a normal diet without restrictions during pregnancy and lactation. For all infants, exclusive breastfeeding is recommended for at least first 4-6 months of life. If breastfeeding is insufficient or not possible, infants at high-risk can be recommended a hypoallergenic formula with a documented preventive effect for the first 4 months. There is no need to avoid introducing complementary foods beyond 4 months, and currently, the evidence does not justify recommendations about either withholding or encouraging exposure to potentially allergenic foods after 4 months once weaning has commenced, irrespective of atopic heredity. There is no evidence to support the use of prebiotics or probiotics for food allergy prevention.

Food Allergy

Food allergy has established itself as a matter of significant public health importance and relevance. It has had substantial impacts across the world and continues to represent the most common cause of anaphylaxis seen in emergent settings. However, its increasing incidence has yielded a silver lining of increased interest and investment, which has powered major research in the field. Much has been learned about food allergy as a result. Recent work has elicited increased understanding about food allergy prevalence, mechanisms, and risk factors. In turn, this has allowed for application of this understanding to potential treatments. Current practice of food allergy treatment through restricted exposure may ultimately be replaced with novel therapies including, perhaps ironically, introduction of the allergenic foods in question. This review presents broad highlights of the rapidly increasing understanding into food allergy mechanisms and experimental therapies.

Safety considerations: breastfeeding after transplant

Organ transplant is an effective treatment for end-stage organ failure. For women, restoration of organ function can restore fertility and the ability to successfully carry a pregnancy. Posttransplant pregnancies have been reported among recipients of all types of solid organ transplants via case and center reports plus registry data. Stable graft function is dependent on prevention of rejection, currently accomplished by using maintenance immunosuppressant medications, to which the fetus is exposed in utero. Common among neonatal outcomes in transplant recipients are preterm and low-birth-weight infants. Emotional, nutritional, and immunologic benefits of breastfeeding have been well-documented and could be valuable for these newborns. Concern must be directed at the effects of the child's exposure to immunosuppressive agents excreted into the breast milk. Breastfeeding could be considered in transplant recipients if it can be shown that the level of exposure does not result in risks to the newborn, immediately and throughout childhood. Despite concerns of health care professionals, some recipients have chosen to breastfeed. Breastfeeding after transplant must be approached with consideration of many issues, and the potential risks require further study. This review focuses on benefits of breastfeeding, common immunosuppressive agents used in organ transplant recipients, a summary of the reports of women who have breastfed their infants while on immunosuppressive therapy and the published studies on breastfeeding and immunosuppressive agents. Recommendations are provided to guide health care professionals to help mothers receiving immunosuppressive agents to make informed choices about breastfeeding their infants.

Donor human milk for preterm infants: current evidence and research directions

The Committee on Nutrition of the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition aims to document the existing evidence of the benefits and common concerns deriving from the use of donor human milk (DHM) in preterm infants. The comment also outlines gaps in knowledge and gives recommendations for practice and suggestions for future research directions. Protection against necrotizing enterocolitis is the major clinical benefit deriving from the use of DHM when compared with formula. Limited data also suggest unfortified DHM to be associated with improved feeding tolerance and with reduced cardiovascular risk factors during adolescence. Presence of a human milk bank (HMB) does not decrease breast-feeding rates at discharge, but decreases the use of formula during the first weeks of life. This commentary emphasizes that fresh own mother's milk (OMM) is the first choice in preterm infant feeding and strong efforts should be made to promote lactation. When OMM is not available, DHM is the recommended alternative. When neither OMM nor DHM is available, preterm formula should be used. DHM should be provided from an established HMB, which follows specific safety guidelines. Storage and processing of human milk reduces some biological components, which may diminish its health benefits. From a nutritional point of view, DHM, like HM, does not meet the requirements of preterm infants, necessitating a specific fortification regimen to optimize growth. Future research should focus on the improvement of milk processing in HMB, particularly of heat treatment; on the optimization of HM fortification; and on further evaluation of the potential clinical benefits of processed and fortified DHM.

10 years after baby-friendly designation: breastfeeding rates continue to increase in a US neonatal intensive care unit

BACKGROUND

Mothers of preterm and sick infants admitted to the neonatal intensive care unit (NICU) often encounter more difficulties with breastfeeding than mothers of healthy term newborns. The extent to which Baby-Friendly designation is associated with breastfeeding rates for NICU infants over time is unknown.

OBJECTIVE

This study aimed to determine the rate of breastfeeding initiation and continuation in a US, inner-city, level 3 NICU 10 years after Baby-Friendly designation.

METHODS

We compared the rate of breastfeeding initiation and continuation among breastfeeding-eligible mothers with infants admitted to the Boston Medical Center NICU in 1999 and 2009, using chi-square tests.

RESULTS

Breastfeeding initiation increased from 74% in 1999 to 85% in 2009 (P = .04). Any breast milk at 2 weeks of age increased from 66% to 80% (P = .05), and exclusive breastfeeding at 2 weeks remained stable between 1999 and 2009. Breastfeeding initiation increased from 68% to 86% among black mothers from 1999 to 2009 (P = .01).

CONCLUSION

Improvement in breastfeeding initiation and any breastfeeding at 2 weeks of age continued 10 years after Baby-Friendly designation among mothers with NICU infants in a US, inner-city, level 3 NICU.

Human milk and the nutritional needs of preterm infants

Key principles underpinning feeding guidelines for preterm infants include support for developmental care, breastfeeding, milk expression, and creating feeding plans. Early trophic feeding with colostrum and transitional milk improves immune protection and promotes gut maturation. Studies of preterm infants demonstrate that feeding mother's milk (MM) decreases the incidence of infection and necrotizing enterocolitis and improves neurodevelopmental outcome but may decrease ponderal and linear growth. Standard practice in neonatal units is to promote mother's own milk as the feed of choice for all infants. However, it is not feasible or prudent to do so for all preterm infants. Mothers of preterm infants have lower rates of successful breastfeeding compared with those of term infants. MM can contain harmful bacterial or viral pathogens. Although preterm human milk (HM) contains higher concentrations of protein, sodium, zinc, and calcium than mature HM, it falls short of supplying adequate quantities of nutrients required by preterm infants. Therefore, HM supplemented with nutrients is recommended for all infants born before 32 weeks gestation and for certain infants born at 32-36 weeks of gestation. HM is the preferred feed, but preterm formula is an appropriate option when there is an inadequate supply of MM.

Immunological programming by breast milk creates an anti-inflammatory cytokine milieu in breast-fed infants compared to formula-fed infants

Breast milk provides important maturational stimuli to an infant's developing immune system. However, data concerning the role of breast-feeding in reducing the risk of allergic disease remain contradictory. Previous studies have centred on comparative analyses of breast milk and formula compositions. We chose a slightly different angle, whereby we focused on the effects of the chosen diet on the infant himself, comparing the immune development of formula-fed and breast-fed children. The objective of the present study was to determine how the mode of feeding affects infant immunology. Altogether, eighteen formula-fed infants with limited breast-feeding for ,3 months and twenty-nine infants who were exclusively breast-fed for .3 months were included in the study. Concentrations of interferon g, TNF-a IL-10, IL-5, IL-4 and IL-2 were measured simultaneously from the same serum sample through use of a multiplexed flow cytometric assay at the ages of 1, 3, 6 and 12 months. Transforming growth factor β2 (TGF-β2) was measured using ELISA at the same time points. Serum TNF-a and IL-2 concentrations were significantly higher in formula-fed than in breast-fed infants during the first year of life (ANOVA, P=0·002). The serum concentrations of TGF-b were significantly lower in formula-fed than in breast-fed infants throughout the first year of life (ANOVA, P≤0·0001). Exclusive breast-feeding promotes an anti-inflammatory cytokine milieu, which is maintained throughout infancy. Such an immunological environment limits hyper-responsiveness and promotes tolerisation, possibly prohibiting the onset of allergic disease.

How should an incident case of atopic dermatitis be defined? A systematic review of primary prevention studies

BACKGROUND

Eczema prevention is now an active area of dermatologic and allergy research. Defining an incident case is therefore a prerequisite for such a study.

OBJECTIVE

We sought to examine how an incident case of atopic dermatitis was defined in previous atopic dermatitis prevention studies in order to make recommendations on a standard definition of new atopic dermatitis cases for use in future prevention trials.

METHODS

We conducted a systematic review of controlled interventional atopic dermatitis prevention studies by using searches of MEDLINE and Cochrane databases for studies published from 1980 to the end of January 2011. Studies that included atopic dermatitis as a secondary outcome, such as asthma prevention trials, were included.

RESULTS

One hundred two studies were included in the final analysis, of which 27 (26.5%) did not describe any criteria for defining an incident case of atopic dermatitis. Of the remaining 75 studies with reported disease criteria, the Hanifin-Rajka criteria were the most commonly used (28 studies). A disease definition unique to that particular study (21 studies) was the second most commonly used disease definition, although the sources for such novel definitions were not cited.

CONCLUSIONS

The results from this systematic review highlight the need for improved reporting and standardization of the definition used for an incident case in atopic dermatitis prevention studies. Most prevention studies have used disease definitions such as the Hanifin-Rajka criteria that include disease chronicity. While acceptable for cumulative incidence outcomes, inclusion of disease chronicity precludes the precise measurement of disease onset. We propose a definition based on existing scientific studies that could be used in future prospective studies.

Breastfeeding and allergy: the evidence

Whether breastfeeding protects against the development of allergic disease has been a frequent subject of study and debate for 75 years. This paper summarizes the published evidence concerning the risks of atopic dermatitis, asthma, allergic rhinitis, positive allergen skin tests, and food allergy associated with infant feeding. The summary is based largely on systematic reviews and meta-analyses carried out by other authors. In addition, I also incorporate the evidence from our long-term follow-up of Belarusian children participating in a cluster-randomized trial of a breastfeeding promotion intervention.

Allergic diseases among very preterm infants according to nutrition after hospital discharge

To determine whether a cow's milk-based human milk fortifier (HMF) added to mother's milk while breastfeeding or a cow's milk-based preterm formula compared to exclusively mother's milk after hospital discharge, increases the incidence of developing allergic diseases among very preterm infants (VPI) during the first year of life. Of a cohort of 324 VPI (gestational age 24-32 wk), the exclusively breastfed VPI were shortly before discharge randomized to breastfeeding without fortification or supplementing with a fortifier. Those not breastfed were fed a preterm formula. The intervention period was from discharge until 4 months corrected age (CA). Follow-up was performed at 4 and 12 months CA including specific IgE to a panel of allergens at 4 months CA. The incidence during and prevalence at 12 months CA of recurrent wheezing (RW) was 39.2% and 32.7%, while atopic dermatitis (AD) was 18.0% and 12.1%, respectively. Predisposition to allergic disease increased the risk of developing AD (p=0.04) [OR 2.6 (95% CI 1.0-6.4)] and the risk of developing RW (p=0.02) [OR 2.7 (95% CI 1.2-6.3)]. Boys had an increased risk of developing RW (p=0.003) [OR 3.1 (95% CI 1.5-6.5)]. No difference was found between nutrition groups. None developed food allergy. Compared to exclusively breastfed, VPI supplemented with HMF or fed exclusively a preterm formula for 4 months did not have an increased risk of developing allergic diseases during the first year of life.

Breast-feeding and cardiovascular risk factors and outcomes in later life: evidence from epidemiological studies

This paper considers the body of observational evidence examining the association of being breast-fed to cardiovascular risk factors and outcomes in later life, and whether any potentially advantageous findings are causal. Early cardiovascular consequences/correlates of breast-feeding, compared to being formula fed, include markedly higher levels of total blood cholesterol, lower levels of pre-prandial blood glucose and insulin and lower levels of adiposity. However, a key issue is whether these early differences at a period of rapid development programme/influence cardiovascular risk factors and outcomes in later life. Evidence of long-term effects of early feeding, largely from observational studies, has shown that those breast-fed have lower levels of blood total cholesterol, lower risk of type-2 diabetes and marginally lower levels of adiposity and blood pressure in adult life. There is no strong evidence to suggest effects of early feeding on adult levels of blood glucose, blood insulin and CHD outcomes, although further data are needed. However, the influence of confounding factors, such as maternal body size, maternal smoking and socio-demographic factors, and exclusivity of early feeding on these potentially beneficial associations needs to be considered before inferring any causal effects. Moreover, fewer studies have examined whether duration of exclusive breast-feeding has a graded influence on these risk factors and outcomes; such data would help further in deciding upon causal associations. While strong observational evidence suggests nutritional programming of adult cholesterol levels, associations with other markers of cardiometabolic risk and their consequences in later life need to be confirmed in well-conducted observational and experimental studies.

Can food allergy be prevented? The current evidence

Food allergy is a recognized public health concern, for which preventative strategies are required. Although an intervention that adequately protects against the development of food allergy has still to be identified, limited benefits have been shown for the prevention of related allergic conditions such as eczema, and to a lesser extent asthma and rhinitis; these benefits are usually limited to at-risk populations. Prevention strategies need to be tested using randomized controlled study designs that account for the numerous methodological challenges, safety concerns, and necessary ethical limitations.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Correlation between early neonatal diet and atopic symptoms up to 5-7 years of age in very low birth weight infants: follow-up of randomized, double-blind study

The influence of early feeding on the risk of atopic diseases has been studied in full-term newborns, not in very low birth weight infants (VLBW). The study evaluated effect of early feeding of VLBW infants with either cow's milk-based formula (CMF) or extensively hydrolyzed milk formula (HF) on incidence of atopic diseases and markers of atopy at 5-7 years of age. This was a follow-up of the randomized, double-blind study evaluating the influence of different enteral feeding protocols on the early morbidity of VLBW infants. In the original study 80 children were randomly allocated into 2 groups receiving during first month of life HF (experimental group) or CMF (control group). At the age of 5-7 years, 62 children among 74 available (84%) with mean birthweight 1124g were evaluated according to standardized ISAAC (International Study of Asthma and Allergies in Childhood) protocol. Total IgE level, specific IgE, lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio and skin prick tests (SPT) were done. Prevalence of obvious allergic diseases was not significantly different between the studied groups (HF: 12/33; CMF: 6/29; RR [relative risk] HF vs CMF: 1.76; 95%CI [confidence interval]: 0.76-4.09). Comparison of atopic status across groups revealed similar rate of positive markers of atopy: IgE (RR: 2.57 95%CI: 0.91-8,08), SPT (RR: 5.13; 95%CI: 0.93-31.6), lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio (OR: 2.32; 95%CI: 0.78-7.53) in the both studied groups. Based on the carried out follow-up study we were unable to confirm the usefulness of hydrolyzed formula in prevention of allergy in an unselected cohort of very low birth weight infants.

WITHDRAWN: Cow's milk protein avoidance and development of childhood wheeze in children with a family history of atopy

BACKGROUND

In infants with a family history of atopy, food allergen avoidance has been advocated as means of preventing the development of atopic disease, when breast-feeding is not possible or supplemental feeding is needed. Most infant formulas are based on cow's milk protein. Alternative choices include soya based and hydrolysed cows milk formulas.

OBJECTIVES

To estimate the effect of dietary avoidance of cow's milk protein on the development of asthma or wheeze in children.

SEARCH STRATEGY

We searched the Cochrane database for eligible trials until February 2002. We obtained the full text papers of all abstracts identified as RCTs and two reviewers independently reviewed them.

SELECTION CRITERIA

We included randomised controlled trials involving children with a family history of atopy in at least one first degree relative, if feeding with cow's milk based standard formula was compared to dietary avoidance of cow's milk protein, using soya or other hypoallergenic formula during the initial four months of life or longer.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. A priori defined subgroups were the types of hypoallergenic artificial feed and dietary restrictions on mother and/or child's diet.

MAIN RESULTS

Six trials used hydrolysed formula for at least four months, in addition to dietary restrictions and in some cases dust-mite reduction measures. The risk of infants experiencing asthma or wheeze during the first year of life was reduced compared to standard cow's milk based formula (Relative Risk 0.40, 95% Confidence Intervals 0.19 to 0.85). Feeding soya-based formula as opposed to standard cow's milk formula did not reduce the risk of having asthma or wheeze at any age.

AUTHORS' CONCLUSIONS

Breast-milk should remain the feed of choice for all babies. In infants with at least one first degree relative with atopy, hydrolysed formula for a minimum of four months combined with dietary restrictions and environment measures may reduce the risk of developing asthma or wheeze in the first year of life. There is insufficient evidence to suggest that soya-based milk formula has any benefit.

The risk of developing food allergy in premature or low-birth-weight children

BACKGROUND

Premature or low-birth-weight children have increased gut permeability compared with term or normal-birth-weight children.

OBJECTIVE

To determine whether premature or low-birth-weight children have an increased risk of developing food allergy compared with term or normal-birth-weight children.

METHODS

The 1995 Manitoba Birth Cohort was studied using the Manitoba Health Services Insurance Plan (MHSIP) database. This database is a population-based, health care administrative and prescription database. It has records of every child born and subsequent utilization of the provincial health care system. The diagnosis of food allergy (ICD-9-CM code of 693 in hospital/medical claims or a prescription of injectable epinephrine excluding a sole diagnosis of venom allergy) was obtained up until the year 2002. The relative risks of food allergy in premature or low-birth-weight children compared with term or normal-birth-weight children were determined.

RESULTS

A total of 13,980 children were born in 1995 and continue to live in the province of Manitoba. Of these, 592 children (4.23%) were found to have food allergy and epinephrine was prescribed in 316 (2.26%) children. No gestational age or birth weight group had a statistically significant increased risk for food allergy.

CONCLUSION

Prematurity and low birth weight are not associated with a change in risk for development of food allergy in childhood.

CLINICAL IMPLICATIONS

Immaturity of the gastrointestinal tract or immune response does not seem to change the risk for development of food allergies. We ask whether early exposure to food antigens may protect premature children by increasing immune tolerance to those antigens.

Support for breastfeeding mothers

BACKGROUND

There is extensive evidence of the benefits of breastfeeding for infants and mothers. In 2003, the World Health Organization (WHO) recommended infants be fed exclusively on breast milk until six months of age. However, breastfeeding rates in many developed countries continue to be resistant to change.

OBJECTIVES

To assess the effectiveness of support for breastfeeding mothers.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2006), MEDLINE (1966 to November 2005), EMBASE (1974 to November 2005) and MIDIRS (1991 to September 2005).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing extra support for breastfeeding mothers with usual maternity care.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

We have included 34 trials (29,385 mother-infant pairs) from 14 countries. All forms of extra support analysed together showed an increase in duration of 'any breastfeeding' (includes partial and exclusive breastfeeding) (relative risk (RR) for stopping any breastfeeding before six months 0.91, 95% confidence interval (CI) 0.86 to 0.96). All forms of extra support together had a larger effect on duration of exclusive breastfeeding than on any breastfeeding (RR 0.81, 95% CI 0.74 to 0.89). Lay and professional support together extended duration of any breastfeeding significantly (RR before 4-6 weeks 0.65, 95% 0.51 to 0.82; RR before 2 months 0.74, 95% CI 0.66 to 0.83). Exclusive breastfeeding was significantly prolonged with use of WHO/UNICEF training (RR 0.69, 95% CI 0.52 to 0.91). Maternal satisfaction was poorly reported.

AUTHORS' CONCLUSIONS

Additional professional support was effective in prolonging any breastfeeding, but its effects on exclusive breastfeeding were less clear. WHO/UNICEF training courses appeared to be effective for professional training. Additional lay support was effective in prolonging exclusive breastfeeding, while its effects on duration of any breastfeeding were uncertain. Effective support offered by professionals and lay people together was specific to breastfeeding and was offered to women who had decided to breastfeed. Further trials are required to assess the effectiveness (including cost-effectiveness) of both lay and professional support in different settings, particularly those with low rates of breastfeeding initiation, and for women who wish to breastfeed for longer than three months. Trials should consider timing and delivery of support interventions and relative effectiveness of intervention components, and should report women's views. Research into appropriate training for supporters (whether lay or professional) of breastfeeding mothers is also needed.

Formulas containing hydrolysed protein for prevention of allergy and food intolerance in infants

BACKGROUND

Allergies and food reactions are common and may be associated with foods including adapted cow's milk formula. Formulas containing hydrolysed proteins have been used to treat infants with allergy or food intolerance. However, it is unclear whether hydrolysed formula can be advocated for prevention of allergy and food intolerance in infants without evidence of allergy or food intolerance.

OBJECTIVES

To determine the effect of feeding hydrolysed formulas on allergy and food intolerance in infants and children compared to adapted cow's milk or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective including extensively and partially hydrolysed formulas. To determine which infants benefit, including infants at low or high risk of allergy and infants receiving early, short term or prolonged formula feeding.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. The review was updated with searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966-March 2006), EMBASE (1980-March 2006) and CINAHL (1982-March 2006) and previous reviews including cross references.

SELECTION CRITERIA

Randomised and quasi-randomised trials that compare the use of a hydrolysed infant formula to human milk or cow's milk formula. Trials with >80% follow up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligibility of studies for inclusion, methodological quality and data extraction were assessed independently by each review author. Primary outcomes included clinical allergy, specific allergies and food intolerance. Meta-analysis was conducted using a fixed effects model.

MAIN RESULTS

Two trials compared early, short term hydrolysed formula to human milk feeding. No significant difference in infant allergy or childhood cow's milk allergy (CMA) were reported. No eligible trial compared prolonged hydrolysed formula to human milk feeding. Two trials compared early, short term hydrolysed formula to cow's milk formula feeding. No significant benefits were reported. One large quasi-random study reported a reduction in infant CMA of borderline significance in low risk infants (RR 0.62, 95% CI 0.38, 1.00). Ten eligible studies compared prolonged feeding with hydrolysed formula versus cow's milk formula in high risk infants. Meta-analysis found a significant reduction in infant allergy (seven studies, 2514 infants; typical RR 0.79, 95% CI 0.66, 0.94), but not in the incidence of childhood allergy (two studies, 950 infants; typical RR 0.85, 95% CI 0.69, 1.05). There was no significant difference in infant eczema (eight studies, 2558 infants, typical RR 0.84, 95% CI 0.68, 1.04), childhood eczema incidence (two studies, 950 infants, typical RR 0.83, 95% CI 0.63, 1.10), childhood eczema prevalence (one study, 872 infants; RR 0.66, 95% CI 0.43, 1.02), or infant or childhood asthma, rhinitis and food allergy. One study reported a significant reduction in infants with CMA with confirmed atopy (RR 0.36, 95% CI 0.15, 0.89). Subgroup analysis of trials blinded to formula found no significant difference in infant allergy (four studies, 2156 infants; typical RR 0.87, 95% CI 0.69, 1.08) or childhood allergy incidence (one study, 872 infants; RR 0.91, 95% CI 0.73, 1.14). No eligible trial examined the effect of prolonged hydrolysed formula feeding on allergy beyond early childhood. There is evidence that preterm or low birthweight infants fed a hydrolysed preterm formula have significantly reduced weight gain, but not in other growth parameters (head circumference or length). Studies in term infants report no adverse effects on growth. Subgroup analysis of trials of partially hydrolysed versus cow's milk formula found a significant reduction in infant allergy (six studies, 1391 infants; typical RR 0.79, 95% CI 0.65, 0.97) but not childhood allergy, or infant or childhood asthma, eczema or rhinitis. Methodological concerns were the same as for the overall analysis. Analysis of trials of extensively hydrolysed formula versus cow's milk formula found no significant differences in allergy or food intolerance. Infants fed extensively hydrolysed formula compared with partially hydrolysed formula had a significant reduction in food allergy (two studies, 341 infants; typical RR 0.43, 95% CI 0.19, 0.99), but there was no significant difference in all allergy or any other specific allergy incidence. Comparing extensively hydrolysed casein containing formula with cow's milk formula, one study (431 infants) reported a significant reduction in childhood allergy incidence (RR 0.72, 95% CI 0.53, 0.97). Meta-analysis found a significant reduction in infant eczema (three studies, 1237 infants; typical RR 0.71, 95% CI 0.51, 0.97). One study reported a significant reduction in childhood eczema incidence (RR 0.66, 95% CI 0.44, 0.98) and prevalence (RR 0.50, 95% CI 0.27, 0.92).

AUTHORS' CONCLUSIONS

There is no evidence to support feeding with a hydrolysed formula for the prevention of allergy compared to exclusive breast feeding. In high risk infants who are unable to be completely breast fed, there is limited evidence that prolonged feeding with a hydrolysed formula compared to a cow's milk formula reduces infant and childhood allergy and infant CMA. In view of methodological concerns and inconsistency of findings, further large, well designed trials comparing formulas containing partially hydrolysed whey, or extensively hydrolysed casein to cow's milk formulas are needed.