Maternal pre-pregnancy obesity and diagnosis of asthma in offspring at age 3 years

Associations between pre-pregnancy obesity and asthma symptoms in adolescents

Background

The high prevalence of children's asthma symptoms, worldwide, is unexplained. We examined the relation between maternal pre-pregnancy weight and body mass index (BMI), and asthma symptoms in adolescents.

Methods

Data from 6945 adolescents born within the Northern Finland Birth Cohort 1986 were used. Prospective antenatal and birth outcome data, including maternal pre-pregnancy weight and BMI, and asthma symptoms in adolescent offspring at age 15–16 years, were employed. Logistic regression analyses were performed to examine the associations between relevant prenatal factors and asthma symptoms during adolescence.

Results

Current wheeze (within the past year) was reported by 10.6% of adolescents, and physician-diagnosed asthma by 6.0%. High maternal pre-pregnancy BMI was a significant predictor of wheeze in the adolescents (increase per kilogram per square metre unit; 2.7%, 95% CI 0.9 to 4.4 for ever wheeze; 3.5%, 95% CI 1.3 to 5.8 for current wheeze), and adjusting for potential confounders further increased the risk (2.8%, 95% CI 0.5 to 5.1; 4.7%, 95% CI 1.9 to 7.7, respectively). High maternal pre-pregnancy weight, in the top tertile, also significantly increased the odds of current wheeze in the adolescent by 20% (95% CI 4 to 39), and adjusting for potential confounders further increased the risk (OR=1.52, 95% CI 1.19 to 1.95). Results were similar for current asthma. Furthermore, these significant associations were observed only among adolescents without parental history of atopy but not among those with parental history of atopy.

Conclusions

The association demonstrated here between maternal pre-pregnancy overweight and obesity, and asthma symptoms in adolescents suggests that increase in asthma may be partly related to the rapid rise in obesity in recent years.

Maternal obesity and infant outcomes

Obesity (Body mass index (BMI) above 30) is one of the major health issues of the 21st century. Over 1.1 billion of the world's population are now classified as obese. In the UK, women are more likely to be obese than men; over 50% of women of reproductive age are overweight or obese. Maternal obesity and the plethora of associated conditions, have a serious impact on the health and development of their offspring. In this review we describe the direct and indirect impact of maternal obesity on the health of the baby. Maternal obesity affects conception, duration and outcome of pregnancy. Offspring are at increased risk of both immediate and long term implications for health. We also briefly review potential mechanisms drawing on data from human and animal studies, and on the outcomes of clinical interventional studies.

The influence of a high-fat dietary environment in the fetal period on postnatal metabolic and immune function

Few reports show whether a high-fat (HF) dietary environment in the fetal period affects immune function or the development of lifestyle-related disease at maturity. We examined the influence of an HF dietary environment in the fetal period on postnatal metabolic and immune function. A total of 16 pregnant mice were given control (CON) diet and 16 were given HF diet in the gestational period, from mating to delivery. After delivery lactating mice were given either CON or HF diet, resulting in four groups. After weaning, the offspring mice were given the same diet that their mothers received during lactation. HF dietary intake in the postnatal period increased fat pad weights, serum glucose, and leptin levels. An HF diet in the fetal period resulted in fewer splenic lymphocytes, a thinner thymic cortex, and impaired antigen-specific immune reactions. Furthermore, tumor necrosis factor (TNF)-alpha production and serum triglyceride levels were elevated in the fetal HF group. In addition, the HF-HF group showed a consistent decrease in ovalbumin (OVA)-specific IgG and elevation of IgE, associated with advanced fatty changes in the liver. Results from this study suggest that HF environment during the fetal period induces epigenetic propensity toward obesity and immunological burden in part due to increased adipose tissue mass, significant reduction in the number of immune cells and decreased activities of immune cells.

Impact of maternal obesity on offspring obesity and cardiometabolic disease risk

The prevalence of obesity among pregnant women is increasing. In addition to the short-term complications of obesity during pregnancy in both mother and child, it is now recognised that maternal obesity has long-term adverse outcomes for the health of her offspring in later life. Evidence from both animal and human studies indicates that maternal obesity increases the risk for the offspring in developing obesity and altering body composition in child- and adulthood and, additionally, it also has an impact on the offspring's cardiometabolic health with dysregulation of metabolism including glucose/insulin homoeostasis, and development of hypertension and vascular dysfunction. Potential mechanisms include effects on the development and function of adipose tissue, pancreas, muscle, liver, the vasculature and the brain. Further studies are required to elucidate the mechanisms underpinning the programming of disease risk in the offspring as a consequence of maternal obesity. The ultimate aim is to identify potential targets, which may be amenable to prevention or early intervention in order to improve the health of this and future generations.

Maternal Pre-Pregnancy Obesity and Recurrent Wheezing in Early Childhood

A number of studies have linked obesity with asthma in adults and children. Few longitudinal studies have evaluated the effect of maternal pre-pregnancy obesity on either asthma or early childhood respiratory morbidity, and these have not been in urban, nonwhite populations. We sought to determine whether pre-pregnancy obesity was associated with recurrent wheezing in an urban, nonwhite population. This study includes 1,191 children from the Boston Birth Cohort (1998-present) followed prospectively to a mean age of 3.0 ± 2.4 years with study visits aligned with the pediatric primary care schedule. Multivariate logistic regression was used to evaluate the associations of maternal pre-pregnancy obesity (body mass index ≥30) with recurrent wheezing (≥4 lifetime episodes). Secondary outcomes included log-transformed cord-blood immunoglobulin E (Phadia), and physician diagnoses of eczema and food allergy. Pre-pregnancy obesity was present in 20.7% of mothers. Of the 1,191 children, 60 (5%) developed recurrent wheezing. Children of obese mothers had an increased risk of recurrent wheezing (adjusted odds ratio, 95% confidence interval: 3.51, 1.68-7.32). These associations persisted even after adjustment for fetal growth status. In contrast, maternal obesity was not associated with eczema or food allergy, and was inversely associated with log cord-blood immunoglobulin E (β, 95% confidence interval: -0.34, -0.66 to -0.02). In this predominantly urban, multiracial/ethnic birth cohort, maternal pre-pregnancy obesity was associated with an increased risk of recurrent wheezing. This association was not explained by fetal growth or increased atopy. Maternal pre-pregnancy obesity is a prevalent risk factor for respiratory morbidity in this urban, nonwhite population.

Maternal overweight before pregnancy and asthma in offspring followed for 8 years

OBJECTIVE

The aim of this study was to investigate the association between maternal overweight before pregnancy and offspring asthma in an ongoing birth cohort study. Maternal overweight may affect the pulmonary and immunological development of the fetus in utero because of the increased levels of inflammatory factors associated with being overweight and thereby increase the asthma risk in childhood.

DESIGN

Birth cohort study with follow-up until 8 years of age.

SUBJECTS

The study population included 3963 children and their mothers who participated in the Prevention and Incidence of Asthma and Mite Allergy study.

MEASUREMENTS

Maternal overweight before pregnancy was defined as a body mass index (BMI) above 25 kg m(-2). Data on wheeze, dyspnea and prescription of inhaled corticosteroids of the child were reported yearly by the parents in a questionnaire. Sensitization to inhalant allergens and bronchial hyperresponsiveness (BHR) were determined at 8 years. Effect modification by predisposition for asthma in the child was tested. Data were analyzed by logistic regression and generalized estimating equations analyses.

RESULTS

At 8 years, 14.4% (n=571) of the children had asthma. In total, 20.9% (n=830) of the mothers were overweight before pregnancy. In children predisposed for asthma (n=1058), maternal overweight before pregnancy was associated with an increased risk of asthma in the child at 8 years (OR=1.52, 95% CI: 1.05-2.18) after adjustment for confounding factors, birth weight and the child's BMI. No association was observed in children without a predisposition (OR=0.86, 95% CI: 0.60-1.23). There was no association with sensitization or BHR.

CONCLUSION

Children with a predisposition for asthma may have a higher risk to develop asthma during childhood when their mothers are overweight before pregnancy, irrespective of the child's BMI.