Maternal nutritional status in pregnancy and blood pressure in childhood

Maternal Anemia and Long-Term Offspring Infectious Morbidity

OBJECTIVE

Anemia of pregnancy is a common condition associated with adverse obstetric outcomes. However, little is known about its long-term effect on the offspring. This study aimed to evaluate a possible association between anemia during pregnancy and the long-term incidence of infectious morbidity in the offspring.

STUDY DESIGN

A large population-based retrospective study was conducted at the Soroka University Medical Center, the sole tertiary medical center in the south of Israel. The study included deliveries between the years 1991 and 2014 and compared long-term infectious morbidity of offspring of women with and without anemia during pregnancy (defined as hemoglobin level below 11 g/dL). The long-term incremental incidence of hospitalizations of offspring up to 18 years of age due to infectious morbidity was evaluated using Kaplan-Meier survival curves, while Cox's regression model was used to control for confounders.

RESULTS

During the study period, 214,244 deliveries met the inclusion criteria, of which 110,775 (51.7%) newborns were born to mothers with anemia during pregnancy. The overall infectious-related hospitalization rate was significantly higher in children from the exposed group (odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.04-1.10, p < 0.01). Kaplan-Meier survival curves showed a significantly higher cumulative incidence of hospitalizations due to infectious diseases as compared with children in the unexposed group (log-rank test, p < 0.01). The Cox model demonstrated a significant and independent association between maternal anemia and the long-term risk for hospitalization due to infectious diseases of the offspring (adjusted hazard ratio [aHR]: 1.09, 95% CI: 1.06-1.12, p < 0.01).

CONCLUSION

Offspring of anemic mothers are at a greater risk for infectious-related hospitalizations in their first 18 years of life.

KEY POINTS

· Anemia is highly common in pregnancy.. · Maternal anemia has multiple short-term implications.. · Our study shows anemia of pregnancy is independently associated with long-term offspring infectious morbidity..

Influence of Breastfeeding on the State of Meta-Inflammation in Obesity-A Narrative Review

Obesity has become an emerging health issue worldwide that continues to grow in females of reproductive age as well. Obesity, as a multisystem and chronic disease, is associated with metabolic inflammation, which is defined as chronic low-grade systemic inflammation mediated by, i.a., adipose tissue macrophages. Lactation has been proven to have a beneficial influence on maternal health and could help restore metabolic balance, especially in the state of maternal obesity. In this review, we aimed to analyze the influence of breastfeeding on chronic low-grade meta-inflammation caused by obesity. We performed a comprehensive literature review using the PubMed, Science Direct, and Google Scholar electronic databases. For this purpose, we searched for "metabolic inflammation"; "meta-inflammation"; "obesity"; "breastfeeding"; "fetal programming"; "energy metabolism"; "postpartum"; "immunity"; "immune system"; and "inflammation" keyword combinations. While the clinical impact of breastfeeding on maternal and offspring health is currently well known, we decided to gain insight into more specific metabolic effects of adiposity, lipid, and glucose homeostasis, and immunological effects caused by the activity of cytokines, macrophages, and other immune system cells. Further research on the immunological and metabolic effects of breastfeeding in obese patients is key to understanding and potentially developing obesity therapeutic strategies.

Maternal overnutrition elevates offspring's blood pressure-A systematic review and meta-analysis

BACKGROUND

Maternal overnutrition during pregnancy predisposes the offspring to cardiometabolic diseases.

OBJECTIVES

This systematic review and meta-analysis aimed to investigate the association between maternal overnutrition and offspring's blood pressure (BP) and the effect of offspring's obesity on this association.

DATA SOURCES

PubMed, EMBASE, Clinicaltrials.gov, CENTRAL.

STUDY SELECTION AND DATA EXTRACTION

Human studies published in English before October 2021 were identified that presented quantitative estimates of association between maternal overnutrition just before or during pregnancy and the offspring's BP.

SYNTHESIS

Random-effect model with the DerSimonian and Laird weighting method was used to analyse regression coefficients or mean differences.

RESULTS

After selection, 17 observational studies (140,517 mother-offspring pairs) were included. Prepregnancy body mass index (ppBMI) showed positive correlation with BP in offspring (regression coefficient for systolic: 0.38 mmHg per kg/m² , 95% confidence interval (CI) 0.17, 0.58; diastolic: 0.10 mmHg per kg/m² , 95% CI 0.05, 0.14). These indicate 1.9 mmHg increase in systolic and 0.5 mmHg increase in diastolic BP of offspring with every 5 kg/m² gain in maternal ppBMI. Results on coefficients adjusted for offspring's BMI also showed association (systolic: 0.08 mmHg per kg/m² , 95% CI 0.04, 0.11; diastolic: 0.03 mmHg per kg/m² , 95% CI 0.01, 0.04). Independent from ppBMI, gestational weight gain (GWG) showed positive correlation with systolic BP (systolic BP: 0.05 mmHg per kg, 95% CI 0.01, 0.09), but not after adjustment for offspring's BMI. Mean systolic BP was higher in children of mothers with excessive GWG than in those of mothers with optimal GWG (difference: 0.65 mmHg, 95% CI 0.25, 1.05).

CONCLUSIONS

Independent from offspring's BMI, higher prepregnancy BMI may increase the risk for hypertension in offspring. The positive association between GWG and offspring's systolic BP is indirect via offspring's obesity. Reduction in maternal obesity and treatment of obesity in children of obese mothers are needed to prevent hypertension.

Resilience to acute kidney injury in offspring of maternal protein restriction

Protein restriction (PR) during pregnancy induces morphofunctional alterations related to deficient nephrogenesis. We studied the renal functional and morphological significance of PR during pregnancy and/or lactation in adult male rat offspring and the repercussions on acute kidney injury (AKI) severity. Female rats were randomly assigned to the following groups: control diet during pregnancy and lactation (CC), control diet during pregnancy and PR diet during lactation (CR), PR during pregnancy and control diet during lactation (RC), and PR during pregnancy and lactation (RR). Three months after birth, at least 12 male offspring of each group randomly underwent either bilateral renal ischemia for 45 min [ischemia-reperfusion (IR)] or sham surgery. Thus, eight groups were studied 24 h after reperfusion: CC, CC + IR, CR, CR + IR, RC, RC + IR, RR, and RR + IR. Under basal conditions, the CR, RC, and RR groups exhibited a significant reduction in nephron number that was associated with a reduction in renal blood flow. Glomerular hyperfiltration was present as a compensatory mechanism to maintain normal renal function. mRNA levels of several vasoactive, antioxidant, and anti-inflammatory molecules were decreased. After IR, renal function was similarly reduced in all of the studied groups. Although all of the offspring from maternal PR exhibited renal injury, the magnitude was lower in the RC and RR groups, which were associated with faster renal blood flow recovery, differential vasoactive factors, and hypoxia-inducible factor-1α signaling. Our results show that the offspring from maternal PR are resilient to AKI induced by IR that was associated with reduced tubular injury and a differential hemodynamic response.

The epigenetics of the hypothalamic-pituitary-adrenal axis in fetal development

The hypothalamic-pituitary-adrenal (HPA) axis is an important hormonal mechanism of the human body and is extremely programmable during embryonic and fetal development. Analyzing its development in this period is the key to understanding in fact how vulnerabilities of congenital diseases occur and any other changes in the phenotypic and histophysiological aspects of the fetus. The environment in which the mother is exposed during the gestational period can influence this axis. Knowing this, our objective was to analyze in recent research the possible impact of epigenetic programming on the HPA axis and its consequences for fetal development. This review brought together articles from two databases: ScienceDirect and PUBMED researched based on key words such as "epigenetics, HPA axis, cardiovascular disease, and circulatory problems" where it demonstrated full relevance in experimental and scientific settings. A total of 101 articles were selected following the criteria established by the researchers. Thus, it was possible to verify that the development of the HPA axis is directly related to changes that occur in the cardiovascular system, to the cerebral growth and other systems depending on the influence that it receives in the period of fetal formation.

In utero programming and early detection of cardiovascular disease in the offspring of mothers with obesity

The offspring of women with obesity during their pregnancy are exposed to an altered intra-uterine environment. A subsequent influence on the cardiovascular development during fetal life is assumed. In the present thematic review, we report on the current knowledge about this early development of cardiovascular disease from fetal life until adolescence. Based on animal studies, different contributing mechanisms have been hypothesized that still need confirmation in human subjects. Insulin resistance, increased levels of leptin, chronic inflammatory state, perturbation of sympathetic tone and epigenetic modifications contribute to a suboptimal nutrient environment and changed hemodynamics. The ensuing aberrant cardiomyocyte development, impaired endothelial cell relaxation and atherogenic lipid profile put these children at risk for the development of endothelial cell dysfunction. Increasing possibilities for early detection of this preliminary stage of atherosclerotic disease offer new insights into future prevention and treatment strategies. Future research should focus on further unraveling the effect of moderate intense, aerobic exercise. Since it is used to treat the condition in children and adolescents with good results, it might be a contributor to tackling endothelial cell dysfunction at its cradle when applied in early pregnancy.

Drosophila melanogaster: An emerging model of transgenerational effects of maternal obesity

The prevalence of obesity in the world is endemic with one rapidly growing health concern being maternal obesity. Obesity during pregnancy increases the risk of gestational diabetes, miscarriage, and preeclampsia, while rendering offspring susceptible to developmental anomalies and long-term metabolic complications including type 2 diabetes and cardiovascular disease. Several studies in humans and rodents demonstrate a correlation between the risks of maternal overnutrition and factors such as epigenetics, mitochondrial dysfunction, insulin resistance, ER stress, and immune system disruption. At present, the molecular mechanisms connecting these factors to maternal obesity are unknown. This review focuses on the use of Drosophila melanogaster to study human metabolic diseases, including obesity, and its emerging use to elucidate the mechanisms of maternal overnutrition and the impact on offspring.

Persistent influence of maternal obesity on offspring health: Mechanisms from animal models and clinical studies

The consequences of excessive maternal weight and adiposity at conception for the offspring are now well recognized. Maternal obesity increases the risk of overweight and obesity even in children born with appropriate-for-gestational age (AGA) birth weights. Studies in animal models have employed both caloric excess and manipulation of macronutrients (especially high-fat) to mimic hypercaloric intake present in obesity. Findings from these studies show transmission of susceptibility to obesity, metabolic dysfunction, alterations in glucose homeostasis, hepatic steatosis, skeletal muscle metabolism and neuroendocrine changes in the offspring. This review summarizes the essential literature in this area in both experimental and clinical domains and focuses on the translatable aspects of these experimental studies. Moreover this review highlights emerging mechanisms broadly explaining maternal obesity-associated developmental programming. The roles of early developmental alterations and placental adaptations are also reviewed. Increasing evidence also points to changes in the epigenome and other emerging mechanisms such as alterations in the microbiome that may contribute to persistent changes in the offspring. Finally, we examine potential interventions that have been employed in clinical cohorts.

Maternal Iron Status in Pregnancy and Long-Term Health Outcomes in the Offspring

Iron is an essential micronutrient and is important not only in carrying oxygen but also to the catalytic activity of a variety of enzymes. In the fetus, it is vital to the synthesis of hemoglobin and in brain development. Iron deficiency (ID) anemia in pregnancy is a common problem, even in high-income country settings. Around 50% of pregnant women worldwide are anemic, with at least half of this burden due to ID. Iron supplements are widely recommended and used during pregnancy globally. However, the evidence on the extent of benefit they contribute to the offspring's health is not well established, and their routine use has its side effects and drawbacks. Dietary iron intake is difficult to assess accurately and it is unlikely to be sufficient to meet the demands of pregnancy if women start with inadequate body iron stores at conception. Evidence from experimental animal models suggests that maternal ID during pregnancy is associated with fetal growth restriction, as well as offspring obesity and high blood pressure later in life. The possible biological mechanisms for this observed association may be due to ID-induced changes in placental structure and function, enzyme expression, nutrient absorption, and fetal organ development. However, such evidence is limited in human studies. Prenatal ID in experimental animal models also adversely affected the developing brain structures, neurotransmitter systems, and myelination resulting in acute brain dysfunction during the period of deficiency and persistence of various postnatal neurobehavioral abnormalities as well as persistent dysregulation of some genes into adult life after iron repletion pointing to the possibility of gene expression changes. The evidence from human population studies is limited and heterogeneous and more research is needed in the future, investigating the effects of ID in pregnancy on future offspring health outcomes.

What Is the Real Public Health Significance of Iron Deficiency and Iron Deficiency Anaemia in Croatia? A Population-Based Observational Study on Pregnant Women at Early Pregnancy from Eastern Croatia

AIM

Studies imply that significance of iron deficiency (ID) and iron deficiency anaemia (IDA) for pregnancy outcomes is especially highlighted in the early pregnancy. Prevalence around the world varies widely, however, no data is available up to date for Croatia or neighbouring countries. Therefore, the objective was to determine the prevalence of ID and IDA among pregnant women from Croatia at the first trimester. Also, the aim was to compare two criterions; the World Health Organization (WHO) one and the clinical one.

METHODS

Randomised observational population based study was set up and 265 pregnant women at the first trimester were enrolled.

RESULTS

Based on the WHO criteria, 17.7% on haemoglobin basis and 18.5% on haematocrit basis had either ID or IDA. Clinical criteria showed that even 32.8% had either ID or IDA (transferrin saturation <20.0%). The WHO criterion shows less sensitivity, especially in detecting less severe stages of IDA.

CONCLUSIONS

Regardless of the criteria used, ID and IDA present a mild to moderate public health problem in pregnant women population. This high share of pregnant women who are starting their pregnancy as iron deficient, presents a potentially high risk for the pregnancy outcomes, especially in terms of a newborn, and it is fully justified to treat them as diseases of public health significance.

External influences on the fetus and their long-term consequences

The observation that low birth weight is associated with cardiovascular disease and its risk factors has formed the basis for the ‘developmental origins' hypothesis. This hypothesis suggests that the operation of adverse influences during intrauterine life leads to permanent alterations in structure and physiology of the adult phenotype which predispose to a range of common adult diseases. The process is known as developmental plasticity or programming and is strongly supported by studies in experimental animals. Recent evidence suggests that the same processes may affect the development of the immune system and play a part in the pathogenesis of autoimmune disease. Animal studies show that the intrauterine environment has powerful and long-lasting effects on many aspects of immune function. The corresponding human evidence, though preliminary, suggests that birth weight or other markers of the early environment are associated with a range of autoimmune diseases.

Programming of Essential Hypertension: What Pediatric Cardiologists Need to Know

Hypertension is recognized as one of the major contributing factors to cardiovascular disease, but its etiology remains incompletely understood. Known genetic and environmental influences can only explain a small part of the variability in cardiovascular disease risk. The missing heritability is currently one of the most important challenges in blood pressure and hypertension genetics. Recently, some promising approaches have emerged that move beyond the DNA sequence and focus on identification of blood pressure genes regulated by epigenetic mechanisms such as DNA methylation, histone modification and microRNAs. This review summarizes information on gene-environmental interactions that lead toward the developmental programming of hypertension with specific reference to epigenetics and provides pediatricians and pediatric cardiologists with a more complete understanding of its pathogenesis.

Birth weight, malnutrition and kidney-associated outcomes--a global concern

An adverse intrauterine environment is associated with an increased risk of elevated blood pressure and kidney disease in later life. Many studies have focused on low birth weight, prematurity and growth restriction as surrogate markers of an adverse intrauterine environment; however, high birth weight, exposure to maternal diabetes and rapid growth during early childhood are also emerging as developmental risk factors for chronic diseases. Altered programming of nephron number is an important link between exposure to developmental stressors and subsequent risk of hypertension and kidney disease. Maternal, fetal, and childhood nutrition are crucial contributors to these programming effects. Resource-poor countries experience the sequential burdens of fetal and childhood undernutrition and subsequent overnutrition, which synergistically act to augment the effects of developmental programming; this observation might explain in part the disproportionate burden of chronic disease in these regions. Numerous nutritional interventions have been effective in reducing the short-term risk of low birth weight and prematurity. Understanding the potential long-term benefits of such interventions is crucial to inform policy decisions to interrupt the developmental programming cycle and stem the growing epidemics of hypertension and kidney disease worldwide.

Dietary and lifestyle advice for pregnant women who are overweight or obese: the LIMIT randomized trial

Overweight and obesity during pregnancy are common and are associated with an increased risk of adverse health outcomes for both the mother and the infant. However, robust evidence about the effect of antenatal dietary and lifestyle interventions on health outcomes is lacking. We conducted a multicenter, randomized trial, recruiting 2,212 women (from 3 public maternity hospitals across South Australia) with a singleton pregnancy between 10⁺⁰ and 20⁺⁰ weeks' gestation and a BMI ≥25. The women were randomized to lifestyle advice (n = 1,108) or standard care (n = 1,104). Women randomized to lifestyle advice participated in a comprehensive dietary and lifestyle intervention over the course of their pregnancy (delivered by research staff), while women randomized to standard care received pregnancy care according to local guidelines, which did not include such information. Provision of the lifestyle intervention was associated with a significant 18% relative risk reduction in the chance of infants being born with a birth weight above 4 kg. No other significant differences were identified in maternal pregnancy and birth outcomes between the two treatment groups. Observational studies highlight the association between a high infant birth weight and the subsequent risk of childhood and adulthood obesity. Antenatal interventions that are effective in reducing high infant birth weights therefore represent a significant strategy to tackle obesity from a population health perspective, while ongoing interrogation of the biospecimens and measurements, including ongoing childhood follow-up, will provide a unique opportunity to evaluate the mechanistic pathways of maternal-to-infant/childhood obesity.

Cytosine methylation changes in enhancer regions of core pro-fibrotic genes characterize kidney fibrosis development

Background

One in eleven people is affected by chronic kidney disease, a condition characterized by kidney fibrosis and progressive loss of kidney function. Epidemiological studies indicate that adverse intrauterine and postnatal environments have a long-lasting role in chronic kidney disease development. Epigenetic information represents a plausible carrier for mediating this programming effect. Here we demonstrate that genome-wide cytosine methylation patterns of healthy and chronic kidney disease tubule samples obtained from patients show significant differences.

Results

We identify differentially methylated regions and validate these in a large replication dataset. The differentially methylated regions are rarely observed on promoters, but mostly overlap with putative enhancer regions, and they are enriched in consensus binding sequences for important renal transcription factors. This indicates their importance in gene expression regulation. A core set of genes that are known to be related to kidney fibrosis, including genes encoding collagens, show cytosine methylation changes correlating with downstream transcript levels.

Conclusions

Our report raises the possibility that epigenetic dysregulation plays a role in chronic kidney disease development via influencing core pro-fibrotic pathways and can aid the development of novel biomarkers and future therapeutics.

Programming of fetal insulin resistance in pregnancies with maternal obesity by ER stress and inflammation

The global epidemics of obesity during pregnancy and excessive gestational weight gain (GWG) are major public health problems worldwide. Obesity and excessive GWG are related to several maternal and fetal complications, including diabetes (pregestational and gestational diabetes) and intrauterine programming of insulin resistance (IR). Maternal obesity (MO) and neonatal IR are associated with long-term development of obesity, diabetes mellitus, and increased global cardiovascular risk in the offspring. Multiple mechanisms of insulin signaling pathway impairment have been described in obese individuals, involving complex interactions of chronically elevated inflammatory mediators, adipokines, and the critical role of the endoplasmic reticulum (ER) stress-dependent unfolded protein response (UPR). However, the underlying cellular processes linking MO and IR in the offspring have not been fully elucidated. Here, we summarize the state-of-the-art evidence supporting the possibility that adverse metabolic postnatal outcomes such as IR in the offspring of pregnancies with MO and/or excessive GWG may be related to intrauterine activation of ER stress response.

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.

Associations of maternal iron intake and hemoglobin in pregnancy with offspring vascular phenotypes and adiposity at age 10: findings from the Avon Longitudinal Study of Parents and Children

BACKGROUND

Iron deficiency is common during pregnancy. Experimental animal studies suggest that it increases cardiovascular risk in the offspring.

OBJECTIVE

To examine the relationship between maternal pregnancy dietary and supplement iron intake and hemoglobin, with offspring's arterial stiffness (measured by carotid-radial pulse wave velocity), endothelial function (measured by brachial artery flow mediated dilatation), blood pressure, and adiposity (measured by body mass index), test for mediation by cord ferritin, birth weight, gestational age, and child dietary iron intake, and for effect modification by maternal vitamin C intake and offspring sex.

DESIGN

Prospective data from 2958 mothers and children pairs at 10 years of age enrolled in an English birth cohort, the Avon Longitudinal Study for Parents and Children (ALSPAC), was analysed.

RESULTS

2639 (89.2%) mothers reported dietary iron intake in pregnancy below the UK reference nutrient intake of 14.8 mg/day. 1328 (44.9%) reported taking iron supplements, and 129 (4.4%) were anemic by 18 weeks gestation. No associations were observed apart from maternal iron intake from supplements with offspring systolic blood pressure (-0.8 mmHg, 99% CI -1.7 to 0, P = 0.01 in the sample with all relevant data observed, and -0.7 mmHg, 99% CI -1.3 to 0, P = 0.008 in the sample with missing data imputed).

CONCLUSION

There was no evidence of association between maternal pregnancy dietary iron intake, or maternal hemoglobin concentration (which is less likely to be biased by subjective reporting) with offspring outcomes. There was a modest inverse association between maternal iron supplement intake during pregnancy with offspring systolic blood pressure at 10 years.

The effect of feeding a low iron diet prior to and during gestation on fetal and maternal iron homeostasis in two strains of rat

BACKGROUND

Iron deficiency anaemia during pregnancy is a global problem, with short and long term consequences for maternal and child health. Animal models have demonstrated that the developing fetus is vulnerable to maternal iron restriction, impacting on postnatal metabolic and blood pressure regulation. Whilst long-term outcomes are similar across different models, the commonality in mechanistic events across models is unknown. This study examined the impact of iron deficiency on maternal and fetal iron homeostasis in two strains of rat.

METHODS

Wistar (n=20) and Rowett Hooded Lister (RHL, n=19) rats were fed a control or low iron diet for 4 weeks prior to and during pregnancy. Tissues were collected at day 21 of gestation for analysis of iron content and mRNA/protein expression of regulatory proteins and transporters.

RESULTS

A reduction in maternal liver iron content in response to the low iron diet was associated with upregulation of transferrin receptor expression and a reduction in hepcidin expression in the liver of both strains, which would be expected to promote increased iron absorption across the gut and increased turnover of iron in the liver. Placental expression of transferrin and DMT1+IRE were also upregulated, indicating adaptive responses to ensure availability of iron to the fetus. There were considerable differences in hepatic maternal and fetal iron content between strains. The higher quantity of iron present in livers from Wistar rats was not explained by differences in expression of intestinal iron transporters, and may instead reflect greater materno-fetal transfer in RHL rats as indicated by increased expression of placental iron transporters in this strain.

CONCLUSIONS

Our findings demonstrate substantial differences in iron homeostasis between two strains of rat during pregnancy, with variable impact of iron deficiency on the fetus. Whilst common developmental processes and pathways have been observed across different models of nutrient restriction during pregnancy, this study demonstrates differences in maternal adaptation which may impact on the trajectory of the programmed response.

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.

The risk of maternal obesity to the long-term health of the offspring

The prevalence of maternal obesity has risen dramatically in recent years, with approximately one in five pregnant women in the UK now classed as obese (body mass index ≥ 30 kg/m(2) ) at antenatal booking. Obesity during pregnancy has been hypothesized to exert long-term health effects on the developing child through 'early life programming'. While this phenomenon has been well studied in a maternal undernutrition paradigm, the processes by which the programming effects of maternal obesity are mediated are less well understood. In humans, maternal obesity has been associated with a number of long-term adverse health outcomes in the offspring, including lifelong risk of obesity and metabolic dysregulation with increased insulin resistance, hypertension and dyslipidaemia, as well as behavioural problems and risk of asthma. The complex relationships between the maternal metabolic milieu and the developing foetus, as well as the potential influence of postnatal lifestyle and environment, have complicated efforts to study the programming effects of maternal overnutrition in humans. This review will examine the emerging evidence from human studies linking maternal obesity to adverse offspring outcomes.

Maternal nutrition and offspring's adulthood NCD's: a review

Overnutrition and undernutrition during pregnancy are closely related to pregnancy outcome as well as neonatal and perinatal outcomes. This and more, from various published data it seems that the effect of maternal nutrition during fetal life stretches far beyond the neonatal period, and influences health issues in adulthood, from cardiovascular and metabolic disorders through mental illnesses. The purpose of this review is to update about overnutrition and undernutrition during pregnancy and their effect on noncommunicable adulthood diseases, and about leading theories on the subject.

Human growth and chronic disease: a memorial to Jim Tanner

CONTEXT

Memorial to Jim Tanner.

OBJECTIVE

To examine the links between early growth and chronic disease in later life.

METHODS

Literature review.

RESULTS

There is now a developmental model for the origins of chronic disease in which the causes to be identified are linked to normal variations in feto-placental, infant and childhood growth and development. These variations lead to variations in the supply of nutrients to the baby that permanently alters gene expression, a process known as 'programming'.

CONCLUSIONS

Variations in the processes of development programme the function of a few key systems that are linked to chronic disease-the immune system, anti-oxidant defences, inflammatory responses, the number and quality of stem cells, neuro-endocrine settings and the balance of the autonomic nervous system. There is not a separate cause for each different disease. Which chronic disease originates during development may depend more on timing than on qualitative differences in exposures to external influences.

Testing the fetal overnutrition hypothesis; the relationship of maternal and paternal adiposity to adiposity, insulin resistance and cardiovascular risk factors in Indian children

OBJECTIVE

We aimed to test the fetal overnutrition hypothesis by comparing the associations of maternal and paternal adiposity (sum of skinfolds) with adiposity and cardiovascular risk factors in children.

DESIGN

Children from a prospective birth cohort had anthropometry, fat percentage (bio-impedance), plasma glucose, insulin and lipid concentrations and blood pressure measured at 9.5 years of age. Detailed anthropometric measurements were recorded for mothers (at 3±2 weeks’ gestation) and fathers (5 years following the index pregnancy).

SETTING

Holdsworth Memorial Hospital, Mysore, India.

SUBJECTS

Children (n 504), born to mothers with normal glucose tolerance during pregnancy.

RESULTS

Twenty-eight per cent of mothers and 38% of fathers were overweight/ obese (BMI≥25.0 kg/m²), but only 4% of the children were overweight/obese (WHO age- and sex-specific BMI≥18.2 kg/m²). The children’s adiposity (BMI, sum of skinfolds, fat percentage and waist circumference), fasting insulin concentration and insulin resistance increased with increasing maternal and paternal sum of skinfolds adjusted for the child’s sex, age and socio-economic status. Maternal and paternal effects were similar. The associations with fasting insulin and insulin resistance were attenuated after adjusting for the child’s current adiposity.

CONCLUSIONS

In this population, both maternal and paternal adiposity equally predict adiposity and insulin resistance in the children. This suggests that shared family environment and lifestyle, or genetic/epigenetic factors, influence child adiposity. Our findings do not support the hypothesis that there is an intrauterine overnutrition effect of maternal adiposity in non-diabetic pregnancies, although we cannot rule out such an effect in cases of extreme maternal obesity, which is rare in our population.

Gestational diabetes mellitus: a positive predictor of type 2 diabetes?

The aim of this paper is to consider the relative benefits of screening for type two diabetes mellitus in women with a previous pregnancy complicated by gestational diabetes mellitus. Recent studies suggest that women who experience GDM are at a greater risk of developing type 2 diabetes within 10-20 years of their index pregnancy. If considered as a stand-alone indicator of the risk of developing type 2 diabetes, GDM is a poor diagnostic test. Most women do not develop GDM during pregnancy and of those that do most do not develop type 2 diabetes. There is, however, a clear need for better early detection of predisposition to disease and/or disease onset to significantly impact on this global pandemic. The putative benefits of multivariate approaches and first trimester and preconception screening to increase the sensitivity of risk assignment modalities for type 2 diabetes are proposed.

Reducing excessive gestational weight gain: lessons from the weight control literature and avenues for future research

Excessive gestational weight gain is a prevalent problem and an independent predictor of future obesity in both mothers and offspring. Intervention research to prevent excessive gestational weight gain is still in its infancy but results to date have been quite modest. Research in weight control outside of pregnancy over the past 30 years has been more robust and identified several key components of effective programs, including use of caloric restriction, daily diet self-monitoring, self-weighing, behavior therapy and ongoing patient-provider contact. The aim of this article is to summarize intervention components shown to be effective in promoting successful weight control outside of pregnancy and explore potential applications in pregnancy. Available evidence suggests that the strategies shown to be effective for weight control outside of pregnancy may also promote better weight control in pregnancy, but several lines for future investigation remain.

Fetoplacental vascular endothelial dysfunction as an early phenomenon in the programming of human adult diseases in subjects born from gestational diabetes mellitus or obesity in pregnancy

Gestational diabetes mellitus (GDM) and obesity in pregnancy (OP) are pathological conditions associated with placenta vascular dysfunction coursing with metabolic changes at the fetoplacental microvascular and macrovascular endothelium. These alterations are seen as abnormal expression and activity of the cationic amino acid transporters and endothelial nitric oxide synthase isoform, that is, the "endothelial L-arginine/nitric oxide signalling pathway." Several studies suggest that the endogenous nucleoside adenosine along with insulin, and potentially arginases, are factors involved in GDM-, but much less information regards their role in OP-associated placental vascular alterations. There is convincing evidence that GDM and OP prone placental endothelium to an "altered metabolic state" leading to fetal programming evidenced at birth, a phenomenon associated with future development of chronic diseases. In this paper it is suggested that this pathological state could be considered as a metabolic marker that could predict occurrence of diseases in adulthood, such as cardiovascular disease, obesity, diabetes mellitus (including gestational diabetes), and metabolic syndrome.

Associations of birth order with early growth and adolescent height, body composition, and blood pressure: prospective birth cohort from Brazil

Birth weight has been inversely associated with later blood pressure. Firstborns tend to have lower birth weight than their later-born peers, but the long-term consequences remain unclear. The study objective was to investigate differences between firstborn and later-born individuals in early growth patterns, body composition, and blood pressure in Brazilian adolescents. The authors studied 453 adolescents aged 13.3 years from the prospective 1993 Pelotas Birth Cohort. Anthropometry, blood pressure, physical activity by accelerometry, and body composition by deuterium were measured. Firstborns (n = 143) had significantly lower birth weight than later borns (n = 310). At 4 years, firstborns had significantly greater weight and height, indicating a substantial overshoot in catch-up growth. In adolescence, firstborns had significantly greater height and blood pressure and a lower activity level. The difference in systolic blood pressure could be attributed to variability in early growth and that in diastolic blood pressure to reduced physical activity. The magnitude of increased blood pressure is clinically significant; hence, birth order is an important developmental predictor of cardiovascular risk in this population. Firstborns may be more sensitive to environmental factors that promote catch-up growth, and this information could potentially be used in nutritional management to prevent catch-up “overshoot.”

Maternal malaria, birth size and blood pressure in Nigerian newborns: insights into the developmental origins of hypertension from the Ibadan growth cohort

Background

Hypertension is an increasing health issue in sub-Saharan Africa where malaria remains common in pregnancy. We established a birth cohort in Nigeria to evaluate the early impact of maternal malaria on newborn blood pressure (BP).

Methods

Anthropometric measurements, BP, blood films for malaria parasites and haematocrit were obtained in 436 mother-baby pairs. Women were grouped to distinguish between the timing of malaria parasitaemia as ‘No Malaria’, ‘Malaria during pregnancy only’ or ‘Malaria at delivery’, and parasite density as low (<1000 parasites/µl of blood) and high (≥1000/µl).

Results

Prevalence of maternal malaria parasitaemia was 48%, associated with younger maternal age (p<0.001), being primigravid (p = 0.022), lower haematocrit (p = 0.028). High parasite density through pregnancy had the largest effect on mean birth indices so that weight, length, head and mid-upper arm circumferences were smaller by 300 g, 1.1 cm, 0.7 cm and 0.4 cm respectively compared with ‘No malaria’ (all p≤0.005). In babies of mothers who had ‘malaria at delivery’, their SBPs adjusted for other confounders were lower respectively by 4.3 and 5.7 mmHg/kg compared with ‘malaria during pregnancy only’ or ‘none’. In contrast the mean newborn systolic (SBP) and diastolic BPs (DBP) adjusted for birth weight were higher by 1.7 and 1.4 mmHg/kg respectively in babies whose mothers had high compared with low parasitaemia.

Conclusions

As expected, prenatal malarial exposure had a significant impact on fetal growth rates. Malaria at delivery was associated with the lowest newborn BPs while malaria through pregnancy, which may attenuate growth of the vascular network, generated higher newborn BPs adjusted for size. These neonatal findings have potential implications for cardiovascular health in sub-Saharan Africa.

Prenatal factors for childhood blood pressure mediated by intrauterine and/or childhood growth?

OBJECTIVE

Some prenatal factors may program an offspring's blood pressure, but existing evidence is inconclusive and mechanisms remain unclear. We examined the mediating roles of intrauterine and childhood growth in the associations between childhood systolic blood pressure (SBP) and 5 potentially modifiable prenatal factors: maternal smoking during pregnancy; prepregnancy BMI; pregnancy weight gain; chronic hypertension; and preeclampsia-eclampsia.

METHODS

The sample contained 30 461 mother-child pairs in the Collaborative Perinatal Project. Prenatal data were extracted from obstetric forms, and children's SBP was measured at 7 years of age. Potential mediation by intrauterine growth restriction (IUGR) and childhood growth was examined by the causal step method.

RESULTS

Heavy maternal smoking during pregnancy was significantly associated with higher offspring SBP (adjusted mean difference versus nonsmoking: 0.73 mm Hg [95% confidence interval (CI): 0.32-1.14]), which attenuated to null (0.13 [95% CI: -0.27-0.54]) after adjustment for changes in BMI from birth to 7 years of age. Prepregnancy overweight-obesity was significantly associated with higher offspring SBP (versus normal weight: 0.89 mm Hg [95% CI: 0.52-1.26]), which also attenuated to null (-0.04 mm Hg [95% CI: -0.40-0.31]) after adjustment for childhood BMI trajectory. Adjustment for BMI trajectory augmented the association between maternal pregnancy weight gain and offspring SBP. Adjustment for childhood weight trajectory similarly changed these associations. However, all these associations were independent of IUGR.

CONCLUSIONS

Childhood BMI and weight trajectory, but not IUGR, may largely mediate the associations of maternal smoking during pregnancy and prepregnancy BMI with an offspring's SBP.

Hydrogenated fat intake during pregnancy and lactation caused increase in TRAF-6 and reduced AdipoR1 in white adipose tissue, but not in muscle of 21 days old offspring rats

Background

Although lipids transfer through placenta is very limited, modification in dietary fatty acids can lead to implications in fetal and postnatal development. Trans fatty acid (TFA) intake during gestation and lactation have been reported to promote dyslipidemia and increase in pro- inflammatory adipokines in offspring. The aim of this study was to evaluate whether the alterations on pro-inflammatory cytokines and dyslipidemia observed previously in 21-d-old offspring of rats fed a diet containing hydrogenated vegetable fat during gestation and lactation were related to alterations in TLR-4, TRAF-6 and adipo-R1 receptor in white adipose tissue and muscle. On the first day of gestation, rats were randomly divided into two groups: (C) received a control diet, and (T) received a diet enriched with hydrogenated vegetable fat, rich in trans fatty acids. The diets were maintained throughout gestation and lactation. Each mother was given eight male pups. On the 21st day of life the offspring were killed. Blood, soleus and extensor digital longus (EDL) muscles, and retroperitoneal (RET) white adipose tissue were collected.

Results

21-d-old of T rats had higher serum triacylglycerols, cholesterol, and insulin. The Adipo R1 protein expression was lower in RET and higher in EDL of T group than C. TLR-4 protein content in all studied tissues were similar between groups, the same was verified in TRAF-6 protein expression in soleus and EDL. However, TRAF-6 protein expression in RET was higher in T than C.

Conclusion

These results demonstrated that maternal ingestion of hydrogenated vegetable fat rich in TFAs during gestation and lactation decrease in Adipo R1 protein expression and increase in TRAF-6 protein expression in retroperitoneal adipose tissue, but not in skeletal muscle, which could contributed for hyperinsulinemia and dyslipidemia observed in their 21-d-old offspring.

Maternal anthropometric characteristics in pregnancy and blood pressure among adolescents: 1993 live birth cohort, Pelotas, southern Brazil

Background

We investigated the association between maternal anthropometric measurements in prepregnancy and at the end of pregnancy and their children's systolic (SBP) and diastolic (DBP) blood pressure at 11 years of age, in a prospective cohort study.

Methods

All hospital births which took place in 1993 in the city of Pelotas - Brazil, were identified (5,249 live births). In 2004, the overall proportion of follow-up was 85% and we obtained arterial blood pressure measurements of 4,452 adolescents.

Results

Independent variables analyzed included maternal prepregnancy weight and body mass index (BMI) and maternal weight, and height at the end of pregnancy. Multiple linear regression analysis controlling for the following confounders were carried out: adolescent's skin color, family income at birth, smoking, alcohol intake during pregnancy, and gestational arterial hypertension. Mean SBP and DBP were 101.9 mmHg (SD 12.3) and 63.4 mmHg (SD 9.9), respectively. Maternal prepregnancy weight and BMI, and weight at the end of pregnancy were positively associated with both SBP and DBP in adolescent subjects of both sexes; maternal height was positively associated with SBP only among males.

Conclusions

Adequate evaluation of maternal anthropometric characteristics during pregnancy may prevent high levels of blood pressure among adolescent children.

Metabolic imprinting, programming and epigenetics – a review of present priorities and future opportunities

Metabolic programming and metabolic imprinting describe early life events, which impact upon on later physiological outcomes. Despite the increasing numbers of papers and studies, the distinction between metabolic programming and metabolic imprinting remains confusing. The former can be defined as a dynamic process whose effects are dependent upon a critical window(s) while the latter can be more strictly associated with imprinting at the genomic level. The clinical end points associated with these phenomena can sometimes be mechanistically explicable in terms of gene expression mediated by epigenetics. The predictivity of outcomes depends on determining if there is causality or association in the context of both early dietary exposure and future health parameters. The use of biomarkers is a key aspect of determining the predictability of later outcome, and the strengths of particular types of biomarkers need to be determined. It has become clear that several important health endpoints are impacted upon by metabolic programming/imprinting. These include the link between perinatal nutrition, nutritional epigenetics and programming at an early developmental stage and its link to a range of future health risks such as CVD and diabetes. In some cases, the evidence base remains patchy and associative, while in others, a more direct causality between early nutrition and later health is clear. In addition, it is also essential to acknowledge the communication to consumers, industry, health care providers, policy-making bodies as well as to the scientific community. In this way, both programming and, eventually, reprogramming can become effective tools to improve health through dietary intervention at specific developmental points.

Association of maternal weight gain in pregnancy with offspring obesity and metabolic and vascular traits in childhood

BACKGROUND

We sought to examine the association of gestational weight gain (GWG) and prepregnancy weight with offspring adiposity and cardiovascular risk factors.

METHODS AND RESULTS

Data from 5154 (for adiposity and blood pressure) and 3457 (for blood assays) mother-offspring pairs from a UK prospective pregnancy cohort were used. Random-effects multilevel models were used to assess incremental GWG (median and range of repeat weight measures per woman: 10 [1, 17]). Women who exceeded the 2009 Institute of Medicine-recommended GWG were more likely to have offspring with greater body mass index, waist, fat mass, leptin, systolic blood pressure, C-reactive protein, and interleukin-6 levels and lower high-density lipoprotein cholesterol and apolipoprotein A1 levels. Children of women who gained less than the recommended amounts had lower levels of adiposity, but other cardiovascular risk factors tended to be similar in this group to those of offspring of women gaining recommended amounts. When examined in more detail, greater prepregnancy weight was associated with greater offspring adiposity and more adverse cardiovascular risk factors at age 9 years. GWG in early pregnancy (0 to 14 weeks) was positively associated with offspring adiposity across the entire distribution but strengthened in women gaining >500 g/wk. By contrast, between 14 and 36 weeks, GWG was only associated with offspring adiposity in women gaining >500 g/wk. GWG between 14 and 36 weeks was positively and linearly associated with adverse lipid and inflammatory profiles, with these associations largely mediated by the associations with offspring adiposity.

CONCLUSIONS

Greater maternal prepregnancy weight and GWG up to 36 weeks of gestation are associated with greater offspring adiposity and adverse cardiovascular risk factors. Before any GWG recommendations are implemented, the balance of risks and benefits of attempts to control GWG for short- and long-term outcomes in mother and child should be ascertained.

Maternal micronutrient deficiency, fetal development, and the risk of chronic disease

Early life nutritional exposures, combined with changes in lifestyle in adult life, can result in increased risk of chronic diseases. Although much of the focus on the developmental origins of disease has been on birth size and growth in postnatal life and the availability of energy and protein during these critical developmental periods, micronutrient deficiencies may also play an important role in fetal growth and development. Micronutrient status in fetal and early life may alter metabolism, vasculature, and organ growth and function, leading to increased risk of cardiometabolic disorders, adiposity, altered kidney function, and, ultimately, to type 2 diabetes and cardiovascular diseases. This review elucidates pathways through which micronutrient deficiencies lead to developmental impairment and describes the research to date on the evidence that micronutrient deficiencies in utero influence the development of chronic disease risk. Animal studies, observational human studies examining maternal diet or micronutrient status, and limited data from intervention studies are reviewed. Where data are lacking, plausible mechanisms and pathways of action have been derived from the existing animal and in vitro models. This review fills a critical gap in the literature related to the seminal role of micronutrients in early life and extends the discussion on the developmental origins of health and disease beyond birth size and energy and protein deficiency.

Antenatal micronutrient supplementation reduces metabolic syndrome in 6- to 8-year-old children in rural Nepal

Previously, we showed that antenatal micronutrient supplementation increases birth weight in a malnourished rural South Asian setting, but the long-term effects are unknown. Between 1999 and 2001, pregnant women were sector-randomized to receive from early pregnancy through 3 mo postpartum daily micronutrient supplements containing either vitamin A alone as the control or with folic acid; folic acid+iron; folic acid+iron+zinc; or a multiple micronutrient supplement that included the above nutrients plus 11 others. From 2006 to 2008, 3524 children (93% of surviving children) were revisited between the ages of 6 and 8 y. Blood pressure, BMI, waist circumference, glycated hemoglobin, cholesterol, triglycerides, glucose, insulin, and the urinary microalbumin:creatinine ratio were assessed among children. Insulin resistance was estimated using the homeostasis model assessment (HOMA) and metabolic syndrome was defined using a modified National Cholesterol Education Program definition. None of the micronutrient supplement combinations affected blood pressure, cholesterol, triglycerides, glucose, insulin, or HOMA. There was a reduced risk of microalbuminuria (> or =3.40 mg/mmol creatinine) in the folic acid [odds ratio (OR), 0.56; 95%CI, 0.33-0.93; P = 0.02) and folic acid+iron+zinc (OR, 0.53; CI, 0.32-0.89; P = 0.02) groups and a reduced risk of metabolic syndrome in the folic acid group (OR, 0.63; CI, 0.41-0.97; P = 0.03). Maternal supplementation with folic acid or folic acid+iron+zinc reduced the risk of kidney dysfunction and, to some extent, metabolic syndrome among children at 6-8 y of age. Supplementation with multiple micronutrients had no such affect. Future follow-up studies are needed to examine long-term supplementation effects on risk of chronic diseases in adults.

Animal models for the study of the developmental origins of health and disease

Human epidemiological studies have indicated that the risk of developing non-communicable diseases in later life may be related to exposures during the developmental period. Developmental life is a vulnerable period of the lifespan during which adverse environmental factors have the potential to disturb the processes of cell proliferation and differentiation or to alter patterns of epigenetic remodelling. Animal models have been instrumental in demonstrating the biological plausibility of the associations observed in human populations, providing proof of principle to the theory of the developmental origins of health and disease (DOHaD). A variety of large- and small-animal models have made important contributions to the field, providing strong evidence of a causal relationship between early-life exposures and metabolic risk factors in later life. Studies of animal models are continuing to contribute to improving the understanding of the mechanisms of the developmental origins of disease. All models have their advantages and disadvantages, and the model that is most appropriate for any particular study is hypotheses dependent. The present review aims to briefly summarise the contributions that animal models have made to the DOHaD field, before reviewing the strengths and weaknesses of these animal models. It is proposed that the integration of evidence from a variety of different models is required for the advancement of understanding within the field.

Pediatric Obesity: It's Time for Prevention before Conception Can Maternal Obesity Program Pediatric Obesity?

Global increases in obesity have led public health experts to declare this disease a pandemic. Although prevalent in all ages, the dire consequences associated with maternal obesity have a pronounced impact on the long-term health of their children as a result of the intergenerational effects of developmental programming. Previously, fetal under-nutrition has been linked to the predisposition to pediatric obesity explained by the adiposity rebound and ‘catch-up’ growth that occurs when a child born to a nutrient deprived mother is exposed to the obesogenic environment of present day. Given the recent increase in maternal overweight/obesity (OW/OB) our attention has shifted from nutrient restriction to overabundance and excess during pregnancy. Consideration must now be given to interventions that could mitigate pregravid body mass index (BMI), attenuate gestational weight gain (GWG) and reduce postpartum weight retention (PPWR) in an attempt to prevent the downstream signaling of pediatric obesity and halt the intergenerational cycle of weight related disease currently plaguing our world. Thus, this paper will briefly review current research that best highlights the proposed mechanisms responsible for the development of child OW/OB and related sequalae (e.g. type II diabetes (T2D) and cardiovascular disease (CVD)) resulting from maternal obesity.

Maternal anemia, iron intake in pregnancy, and offspring blood pressure in the Avon Longitudinal Study of Parents and Children

BACKGROUND

In animals, maternal iron deficiency during pregnancy results in elevated offspring blood pressure (BP). Studies in pregnant women are limited in number, have had inconsistent results, and have not accounted for maternal iron supplementation.

OBJECTIVE

The objective was to assess the association between maternal iron status during pregnancy and offspring BP.

DESIGN

Maternal hemoglobin (n = 1255), iron supplementation (n = 7484), food-based iron intake (n = 7130), and offspring BP were assessed in a prospective cohort at 7 y of age.

RESULTS

Maternal anemia during pregnancy was associated with lower systolic BP in the offspring at 7 y of age (third trimester, age- and sex-adjusted: beta = -1.09; 95% CI: -2.21, -0.05 mm Hg; P = 0.04). Adjustment for confounders attenuated this association (beta = -0.49; 95% CI: -1.71, 0.72 mm Hg; P = 0.4). In women who did not take iron supplements during pregnancy, the observed association with maternal anemia was even stronger: minimally adjusted models (beta = -2.11; 95% CI: -3.61, -0.61 mm Hg; P = 0.006) and fully adjusted models (beta = -1.48; 95% CI: -3.21, 0.25 mm Hg; P = 0.09). Iron supplementation was not associated with offspring BP after confounding by multivitamin intake was accounted for, and no association with iron intake from food was observed.

CONCLUSION

In contrast with animal studies, maternal iron intake during pregnancy is not associated with offspring BP, and some evidence indicates that maternal anemia in contemporary pregnant women is associated with lower offspring BP. It is possible that, in well-nourished populations, low hemoglobin is more likely to reflect greater plasma volume expansion (and thus better maternal and offspring health) than iron deficiency.

Maternal iron intake and iron status during pregnancy and child blood pressure at age 3 years

BACKGROUND

Animal data suggest that maternal iron deficiency during pregnancy leads to lower birth weight and sustained blood pressure elevation in the offspring. In humans, iron deficiency during pregnancy is common and is associated with adverse birth outcomes such as low birth weight. Data are lacking, however, regarding the effects of maternal iron intake and iron status during pregnancy on offspring blood pressure. Our aim was to examine the extent to which lower maternal iron intake, haemoglobin level and mean cell volume (MCV) during pregnancy are associated with higher child systolic blood pressure (SBP) at age 3 years.

METHODS

We studied 1167 participants in Project Viva, a longitudinal cohort study of pregnant women and their children. We estimated first and second trimester maternal iron intake from food frequency questionnaires. We used an electronic laboratory database to identify haemoglobin and MCV levels in pregnancy. We measured child BP up to five times with a Dinamap and used mixed-effects regression models in our analysis.

RESULTS

Mean (SD) child SBP at 3 years was 92.0 (9.9) mmHg. Adjusting for confounders, for each 10 mg increase in first trimester iron intake, child SBP was not lower, but was in fact 0.4 mmHg higher (95% CI 0.1, 0.7). For second trimester iron intake, and for first or second trimester haemoglobin and MCV levels, we did not find any appreciable association with 3 year SBP.

CONCLUSIONS

In contrast to animal studies, we did not find that lower maternal iron status during pregnancy was associated with higher offspring BP.

Maternal and child undernutrition: consequences for adult health and human capital

In this paper we review the associations between maternal and child undernutrition with human capital and risk of adult diseases in low-income and middle-income countries. We analysed data from five long-standing prospective cohort studies from Brazil, Guatemala, India, the Philippines, and South Africa and noted that indices of maternal and child undernutrition (maternal height, birthweight, intrauterine growth restriction, and weight, height, and body-mass index at 2 years according to the new WHO growth standards) were related to adult outcomes (height, schooling, income or assets, offspring birthweight, body-mass index, glucose concentrations, blood pressure). We undertook systematic reviews of studies from low-income and middle-income countries for these outcomes and for indicators related to blood lipids, cardiovascular disease, lung and immune function, cancers, osteoporosis, and mental illness. Undernutrition was strongly associated, both in the review of published work and in new analyses, with shorter adult height, less schooling, reduced economic productivity, and--for women--lower offspring birthweight. Associations with adult disease indicators were not so clear-cut. Increased size at birth and in childhood were positively associated with adult body-mass index and to a lesser extent with blood pressure values, but not with blood glucose concentrations. In our new analyses and in published work, lower birthweight and undernutrition in childhood were risk factors for high glucose concentrations, blood pressure, and harmful lipid profiles once adult body-mass index and height were adjusted for, suggesting that rapid postnatal weight gain--especially after infancy--is linked to these conditions. The review of published works indicates that there is insufficient information about long-term changes in immune function, blood lipids, or osteoporosis indicators. Birthweight is positively associated with lung function and with the incidence of some cancers, and undernutrition could be associated with mental illness. We noted that height-for-age at 2 years was the best predictor of human capital and that undernutrition is associated with lower human capital. We conclude that damage suffered in early life leads to permanent impairment, and might also affect future generations. Its prevention will probably bring about important health, educational, and economic benefits. Chronic diseases are especially common in undernourished children who experience rapid weight gain after infancy.

The developmental origins of adult disease (Barker) hypothesis

Many studies have provided evidence for the hypothesis that size at birth is related to the risk of developing disease in later life. In particular, links are well established between reduced birthweight and increased risk of coronary heart disease, diabetes, hypertension and stroke in adulthood. These relationships are modified by patterns of postnatal growth. The most widely accepted mechanisms thought to underlie these relationships are those of fetal programming by nutritional stimuli or excess fetal glucocorticoid exposure. It is suggested that the fetus makes physiological adaptations in response to changes in its environment to prepare itself for postnatal life. These changes may include epigenetic modification of gene expression. Less clear at this time are the relevance of fetal programming phenomena to twins and preterm babies, and whether any of these effects can be reversed after birth. Much current active research in this field will be of direct relevance to future obstetric practice.