Wheezing and eczema in relation to infant anthropometry: evidence of developmental programming of disease in childhood

Early life programming of health and disease: the long-term consequences of obesity in pregnancy: a narrative review

The prevalence of overweight and obesity is rising in all parts of the world and among young women it presents a very clear danger during pregnancy. Women who are overweight or who gain excessive weight during pregnancy are at greater risk of complications in pregnancy and labour, and are more likely to lose their child to stillbirth, or themselves die during pregnancy. This narrative review considers the evidence that in addition to increasing risk of poor pregnancy outcomes, obesity has the capacity to programme fetuses to be at greater risk of cardiometabolic disorders later in life. An extensive body of evidence from prospective and retrospective cohorts, and record linkage studies demonstrates associations of maternal obesity and/or gestational diabetes with cardiovascular disease, type-1 and type-2 diabetes. Studies in animals suggest that these associations are underpinned by adaptations that occur in fetal life, which remodel the structures of major organs including the brain, kidney and pancreas. This article is protected by copyright. All rights reserved.

Faltering of prenatal growth precedes the development of atopic eczema in infancy: cohort study

Background

Infants with atopic eczema have an increased risk of impaired growth, but the origin of this impairment is unclear. The aim of this study was to examine fetal and infant growth in relation to infantile atopic eczema.

Methods

Within the UK Southampton Women's Survey, 1,759 infants with known maternal menstrual data had anthropometric measurements at 11, 19, and 34 weeks' gestation, birth, and ages 6 and 12 months, enabling derivation of growth velocity SD scores. Infantile atopic eczema at ages 6 and/or 12 months was ascertained using modified UK Working Party diagnostic criteria.

Results

Expressed per SD increase, higher femur length and abdominal circumference at 34 weeks' gestation were associated with decreased risks of atopic eczema (eczema OR/SD increase 0.81 [95% CI 0.69-0.96], P=0.017 and 0.78 [95% CI 0.65-0.93], P=0.006, respectively), while every SD increase in head to abdominal circumference ratio (indicating disproportionate growth) was associated with an increase in risk of atopic eczema (1.37 [1.15-1.63], P=0.001). Lower velocities of linear growth from 11 weeks' gestation to birth and birth to age 6 months were associated with atopic eczema (atopic eczema OR/SD increase 0.80 [0.65-0.98], P=0.034 and 0.8 [1 0.66-1.00], P=0.051, respectively). Infants with atopic eczema at age 12 months had a larger head circumference in early gestation and faltering of abdominal growth velocity from 19 to 34 weeks' gestation (atopic eczema OR/SD increase 0.67 [0.51-0.88], P=0.003).

Conclusion

Infants with atopic eczema demonstrate altered patterns of fetal growth, including faltering of linear growth in utero, prior to the clinical onset of atopic eczema. These findings suggest growth falters prior to the start of clinical atopic eczema and its treatment.

In utero Head Circumference is Associated with Childhood Allergy

BACKGROUND

Altered fetal growth is known to be associated with allergic disease. Specifically, increased head circumference at birth has been linked to asthma and elevated IgE. However, few studies have examined a link between early fetal anthropometry and allergic disease. The aim of this study was to examine head circumference at mid-gestation in children diagnosed with allergy.

METHODS

This was a retrospective cohort study, comprising pregnancies delivered between 10/2006 and 9/2010 at Nepean Hospital, Australia. Exclusion criteria were illegal drug use, alcohol consumption, gestation <35 weeks, and gestational hypertension. Pregnancy data were sourced from the Nepean Obstetric Database. Atopic diseases (asthma, atopic dermatitis, and IgE-mediated food allergy) were assessed by questionnaire at age 1-5 years. Infants from pregnancies with completed questionnaires, who also had a mid-gestation ultrasound scan, were included (N = 121). Multiple logistic regression techniques were used to model head circumference against the development of allergies.

RESULTS

Smaller head circumference at mid-gestation was associated with increased odds of allergic disease in children aged 1-5 years. A 1 mm smaller head circumference was associated with a 7% increased chance of allergies being later diagnosed, adjusted for gestation (95% CI: 1-14%, p = 0.036). Head circumference at mid-gestation was also inversely correlated with the presence of multiple atopic disease.

CONCLUSION

Smaller mid-gestational head circumference is associated with early childhood allergic disease, which suggests that fetal programing of allergic disease occurs before mid-gestation. This suggests that mediators such as brain-derived neurotrophic factor may be dysregulated early in utero in a milieu, which also predisposes to atopic disease.

Nutrition in early life and the programming of adult disease: a review

Foetal development and infancy are life stages that are characterised by rapid growth, development and maturation of organs and systems. Variation in the quality or quantity of nutrients consumed by mothers during pregnancy, or infants during the first year of life, can exert permanent and powerful effects upon developing tissues. These effects are termed 'programming' and represent an important risk factor for noncommunicable diseases of adulthood, including the metabolic syndrome and coronary heart disease. This narrative review provides an overview of the evidence-base showing that indicators of nutritional deficit in pregnancy are associated with a greater risk of type-2 diabetes and cardiovascular mortality. There is also a limited evidence-base that suggests some relationship between breastfeeding and the timing and type of foods used in weaning, and disease in later life. Many of the associations reported between indicators of early growth and adult disease appear to interact with specific genotypes. This supports the idea that programming is one of several cumulative influences upon health and disease acting across the lifespan. Experimental studies have provided important clues to the mechanisms that link nutritional challenges in early life to disease in adulthood. It is suggested that nutritional programming is a product of the altered expression of genes that regulate the cell cycle, resulting in effective remodelling of tissue structure and functionality. The observation that traits programmed by nutritional exposures in foetal life can be transmitted to further generations adds weight the argument that heritable epigenetic modifications play a critical role in nutritional programming.

Fetal growth and risk of childhood asthma and allergic disease

Introduction

Early genetic and environmental factors have been discussed as potential causes for the high prevalence of asthma and allergic disease in the western world, and knowledge on fetal growth and its consequence on future health and disease development is emerging.

Objective

This review article is an attempt to summarize research on fetal growth and risk of asthma and allergic disease. Current knowledge and novel findings will be reviewed and open research questions identified, to give basic scientists, immunologists and clinicians an overview of an emerging research field.

Methods

PubMed-search on pre-defined terms and cross-references.

Results

Several studies have shown a correlation between low birth weight and/or gestational age and asthma and high birth weight and/or gestational age and atopy. The exact mechanism is not yet clear but both environmental and genetic factors seem to contribute to fetal growth. Some of these factors are confounders that can be adjusted for, and twin studies have been very helpful in this context. Suggested mechanisms behind fetal growth are often linked to the feto-maternal circulation, including the development of placenta and umbilical cord. However, the causal link between fetal growth restriction and subsequent asthma and allergic disease remains unexplained. New research regarding the catch-up growth following growth restriction has posited an alternative theory that diseases later on in life result from rapid catch-up growth rather than intrauterine growth restriction per se. Several studies have found a correlation between a rapid weight gain after birth and development of asthma or wheezing in childhood.

Conclusion and clinical relevance

Asthma and allergic disease are multifactorial. Several mechanisms seem to influence their development. Additional studies are needed before we fully understand the causal links between fetal growth and development of asthma and allergic diseases.

Fetal programming of CVD and renal disease: animal models and mechanistic considerations

The developmental origins of health and disease hypothesis postulates that exposure to a less than optimal maternal environment during fetal development programmes physiological function, and determines risk of disease in adult life. Much evidence of such programming comes from retrospective epidemiological cohorts, which demonstrate associations between birth anthropometry and non-communicable diseases of adulthood. The assertion that variation in maternal nutrition drives these associations is supported by studies using animal models, which demonstrate that maternal under- or over-nutrition during pregnancy can programme offspring development. Typically, the offspring of animals that are undernourished in pregnancy exhibit a relatively narrow range of physiological phenotypes that includes higher blood pressure, glucose intolerance, renal insufficiency and increased adiposity. The observation that common phenotypes arise from very diverse maternal nutritional insults has led to the proposal that programming is driven by a small number of mechanistic processes. The remodelling of tissues during development as a consequence of maternal nutritional status being signalled by endocrine imbalance or key nutrients limiting processes in the fetus may lead to organs having irreversibly altered structures that may limit their function with ageing. It has been proposed that the maternal diet may impact upon epigenetic marks that determine gene expression in fetal tissues, and this may be an important mechanism connecting maternal nutrient intakes to long-term programming of offspring phenotype. The objective for this review is to provide an overview of the mechanistic basis of fetal programming, demonstrating the critical role of animal models as tools for the investigation of programming phenomena.

Long term respiratory consequences of intrauterine growth restriction

Epidemiological studies demonstrate that in-utero growth restriction and low birth weight are associated with impaired lung function and increased respiratory morbidity from infancy, throughout childhood and into adulthood. Chronic restriction of nutrients and/or oxygen during late pregnancy causes abnormalities in the airways and lungs of offspring, including smaller numbers of enlarged alveoli with thicker septal walls and basement membranes. The structural abnormalities and impaired lung function seen soon after birth persist or even progress with age. These changes are likely to cause lung symptomology through life and hasten lung aging.

Association among size of thymus, anthropometric dimensions and number of lymphocytes in peripheral blood in newborns from Slovakia

AIMS

Thymus is the central lymphatic organ in humans with important endocrine function that is involved in maturation of immunocompetent T-lymphocytes. In our study we investigated the relationship among thymus size and the anthropometric dimensions as well as between thymus size and the number of lymphocytes in peripheral blood in full-term newborns.

METHODS

The examined group consisted of 212 full-term newborns from the region of Southern Slovakia. We examined birth weight, birth body length, head circumference and chest circumference. Thymus size was estimated by ultrasonography and it was expressed as Thymic Index. The number of lymphocytes in peripheral blood was determined from the number of total leukocytes and from the leukogram.

RESULTS

We have found a statistically significant positive correlation among thymus size and the body dimensions of newborns. The highest correlation with thymus size was found for birth weight (r = 0.409; P < 0.001) followed by birth body length (r = 0.368; P < 0.001), head circumference (r = 0.365; P < 0.001) and chest circumference (r = 0.340; P < 0.001). We have proven also a statistically significant positive correlation between the number of lymphocytes in peripheral blood and thymus size (r = 0.208; P = 0.039).

CONCLUSION

Our results confirmed the findings of other authors about a close relationship of Thymic Index and basic body parameters in newborns.

Maternal obesity in pregnancy and respiratory health in early childhood

Obesity is associated with systemic inflammation, immunological changes, increased risk of respiratory infections and chronic respiratory illness. Maternal obesity in pregnancy increases the risk of pregnancy complications, caesarean sections and adverse birth outcomes, which have in turn been associated with respiratory illness in children. To our knowledge, the possible influence of maternal obesity in pregnancy on respiratory illness in early childhood beyond the newborn period has not been explored. We examined the relationship between a high maternal body mass index (BMI) in pregnancy and lower respiratory tract infections and wheeze up to 18 months of age in the Norwegian Mother and Child Study (MoBa), a population-based cohort study that includes 100,000 pregnant women, conducted at the Norwegian Institute of Public Health. We analysed data from the first 33 192 children, born between 1999 and 2005. In unadjusted analyses maternal obesity in pregnancy was related to both respiratory infections and wheeze in the children. In multivariable analyses, only an effect on wheeze remained. The risk of wheeze increased linearly with maternal BMI in pregnancy, and was 3.3% higher [95% CI 1.2, 5.3] for children with mothers who were obese during pregnancy, than for children of mothers with normal BMI. This effect was not mediated through obesity-related pregnancy complications, low birthweight, preterm birth or caesarean section.

Birth anthropometric measures, body mass index and allergic diseases in a birth cohort study (BAMSE)

OBJECTIVE

We aimed to assess increased birth weight or birth length in relation to allergic diseases at 4 years of age, taking body mass index (BMI) at age 4 as a covariate in the adjustment.

METHODS

The parents of a large prospective birth cohort answered questionnaires on environmental factors and allergic symptoms when their children were 2 months and 1, 2 and 4 years old. Perinatal data on weight and length at birth were received from the child care health centres. The children were clinically examined at 4 years of age and height and weight recorded. Blood was drawn for analysis of specific IgE antibodies to common inhalant allergens. Risk associations between birth anthropometric measures and wheeze, allergic diseases or sensitisation were estimated in multivariate logistic regression analyses (n = 2869).

RESULTS

There were no clear overall associations between birth weight and allergic diseases at 4 years of age. Birth length > or =90th percentile was inversely associated with any wheeze at age 4 (adjusted OR 0.64, 95% CI 0.44 to 0.92) but was significantly associated only with late-onset wheeze (adjusted OR 0.40, 95% CI 0.21 to 0.77). No such associations were seen for persistent or transient wheeze, eczema, rhinitis or allergic sensitisation. Transient wheeze during the first 2 years of age tended to be associated with increased BMI at age 4.

CONCLUSION

Increased birth weight was not associated with wheeze or allergic disease. Increased birth length may play a protective role in late-onset wheeze in early childhood.

Diet and the developing immune system

Undernutrition during fetal life is known to have programming effects upon tissue morphology and function. This generally promotes poor health in adult life, with increased risk of metabolic syndrome and cardiovascular mortality noted among individuals whose growth was constrained in utero. Undernutrition in early life impacts upon the development of the immune organs and appears to diminish cellular immunity and increase the risk of atopic disorders during childhood. A limited body of evidence implicates fetal programming in the development of autoimmune disorders. This area represents an interesting target for further research and preventive medicine.