Birth weight for gestational age and the risk of asthma in childhood and adolescence: a retrospective cohort study

Association between maternal lipid profiles and vitamin D status in second trimester and risk of LGA or SGA: a retrospective study

Background

Accumulating evidence has linked dyslipidemia during pregnancy to the risk of delivering infants born either large for gestational age (LGA) or small for gestational age (SGA). However, the effects of the vitamin D status on these relationships require further investigation. This study investigated whether the relationship between lipid profiles and the risk of LGA or SGA was influenced by vitamin D levels during the second trimester.

Methods

Maternal lipid profile levels, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and vitamin D levels, were measured in a cohort of 6,499 pregnant women during the second trimester. Multivariate regression models and subgroup analyses were employed to evaluate the potential associations between maternal lipid profiles, vitamin D levels, and the risk of LGA or SGA.

Results

The prevalence of SGA infants was 9.8% (n=635), whereas that of LGA infants was 6.9% (n=447). Maternal TG levels were found to be positively associated with the risk of LGA (odds ratio [OR] = 1.41, 95% confidence interval [CI]:1.17-1.70), whereas a negative association was observed between maternal TG, TC, LDL-C levels, and risk of SGA. Additionally, mothers with higher HDL-C levels were less likely to give birth to an LGA infant (OR=0.58, 95% CI:0.39-0.85). Importantly, associations between TG, TC, LDL-c, and SGA as well as between TG and LGA were primarily observed among pregnant women with insufficient vitamin D levels. As for HDL-C, the risk of LGA was lower in mothers with sufficient vitamin D (OR = 0.42, 95% CI:0.18-0.98) compared to those with insufficient vitamin D (OR = 0.65, 95% CI:0.42-0.99).

Conclusion

Vitamin D status during the second trimester exerts a modifying effect on the association between lipid profiles and the risk of LGA and SGA infants.

Relationship Between Birth Weight and Asthma Diagnosis: A Cross-Sectional Survey Study Based on the National Survey of Children's Health in the U.S

OBJECTIVE

To assess the association between birth weight and childhood asthma risk using data from the 2019-2020 National Survey of Children's Health database.

DESIGN

Cross-sectional study.

SETTING

The USA.

PATIENTS

A representative cohort of American children.

EXPOSURE

The exposure of this study was birth weight regardless of gestational age. Birth weight was divided into three groups: <1500 g, 1500-2500 g and >2500 g.

MAIN OUTCOME MEASURES

Primary outcomes were parent-reported diagnosis of asthma.

METHOD

The Rao-Scott χ2 test was used to compare the groups. The main analyses examined the association between birth weight and parent-report asthma in children using univariable and multivariable logistic models adjusting for preterm birth, age, sex, race, family poverty, health insurance, smoking, maternal age. Subgroup analysis was performed based on interaction test.

RESULTS

A total of 60 172 children aged 3-17 years were enrolled in this study; of these, 5202 (~8.6%) had asthma. Children with asthma were more likely to be born preterm, with low birth weight (LBW) or very LBW (VLBW). The incidence of asthma was the highest in VLBW children at 20.9% and showed a downward trend with an increase in birth weight class, with rates of 10.7% and 8.1% in the LBW and normal birthweight groups, respectively. Children with VLBW (OR 1.97; 95% CI 1.29 to 3.01) had higher odds of developing asthma in the adjusted analysis model. However, VLBW was only shown to be a risk factor for asthma among Hispanics, black/African-Americans and children between the ages of 6 and 12 years, demonstrating racial and age disparities.

CONCLUSIONS

VLBW increases the risk of childhood asthma; however, racial and age disparities are evident.

Early-Life Weight Status and Risk of Childhood Asthma or Recurrent Wheeze in Preterm and Term Offspring

BACKGROUND

Excessive weight is associated with the development of childhood asthma. However, trends among preterm and term offspring may differ.

OBJECTIVE

To assess whether the association of longitudinal weight for age (WFA) and odds of asthma/recurrent wheeze in early life differs between children born preterm and those born at term.

METHODS

This study used prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial. Children (n = 804) were followed-up and anthropometric measurements, including WFA, were taken at birth and annually until the age of 6 years. The primary outcome was asthma/recurrent wheeze by age 3 and 6 years.

RESULTS

Among the offspring, 71 (8.8%) were premature. In all the children, the odds of asthma/recurrent wheeze increased by 15% (adjusted odds ratio [aOR], 1.15; 95% CI, 1.10-1.20; P < .001) by age 3 years and 9% (aOR, 1.09; 95% CI, 1.07-1.11; P < .001) by age 6 years for each unit increase in WFA z score. Odds were different between term and preterm offspring (Pinteraction < .001). In term offspring, the odds of having asthma/recurrent wheeze by age 3 and 6 years increased by 22% and 15%, respectively (aOR, 1.22, 95% CI, 1.16-1.27, P < .001, and aOR, 1.15, 95% CI, 1.11-1.18, P < .001). In preterm offspring, by age 3 years, odds of asthma/recurrent wheeze decreased by 10% for each unit increase in WFA z score (aOR, 0.90; 95% CI, 0.81-0.99; P = .030) and decreased by 27% by age 6 years (aOR, .73; 95% CI, 0.61-0.86; P < .001).

CONCLUSIONS

During early life, increasing standardized WFA is associated with higher odds of asthma/recurrent wheeze in term children. In contrast, in preterm children, a higher standardized WFA during catch-up growth may decrease the odds of asthma/recurrent wheeze associated with prematurity.

Non-linear association of birth weight with lung function and risk of asthma: A population-based study

Background

The impact of birth weight on lung function and risk of asthma remains contentious. Our aim was to investigate the specific association of birth weight with lung function and the risk of asthma in children.

Methods

We performed cross-sectional analyses of 3,295 children aged 6-15 years who participated in the 2007-2012 National Health and Nutrition Examination Survey (NHANES). After controlling for potential covariates other than gestational diabetes, maternal asthma and obesity, the linear and non-linear associations of birth weight with lung function metrics and the risk of asthma were evaluated by a generalized linear model and generalized additive model, respectively.

Results

We observed a non-linear association of birth weight with FEV₁ %predicted, FEV₁/FVC %predicted and FEF_{25 - 75} %predicted (P for non-linearity was 0.0069, 0.0057, and 0.0027, respectively). Further threshold effect analysis of birth weight on lung function detected the turning point for birth weight was 3.6 kg. When the birth weight was < 3.6 kg, birth weight was significantly positively associated with all pulmonary function metrics. However, negative associations were found in FEV₁ %predicted, FEV₁/FVC %predicted and FEF_{25 - 75} %predicted when the birth weight was ≥3.6 kg. These results were consistent in the stratified and sensitivity analyses. Additionally, a possible non-linear relationship was also detected between birth weight and the risk of asthma.

Conclusion

Although not all maternal factors were accounted for, our findings provided new insight into the association of birth weight with lung function. Future studies are warranted to confirm the present findings and understand the clinical significance.

What is the impact of birth weight corrected for gestational age on later onset asthma: a meta-analysis

Background

Asthma is a common multifactorial disease affecting millions worldwide. The Barker hypothesis postulates an association between later onset disease risk and energy exposure in utero. Birth weight corrected for gestational age is better for measuring the infant size, which reflects energy exposure in utero. Findings on asthma and birth weight corrected for gestational age have been inconclusive. We conducted a meta-analysis to further clarify the relationship between birth weight corrected for gestational age and later onset asthma.

Methods

A systematic literature search of the PubMed, Web of Science, MEDLINE, and Scopus databases up to January 2021 was conducted. The subject terms were used as follows: “asthma”, “allerg*”, “respiratory”, “birth weight”, “gestational age”, “birth outcomes”, “intrauterine growth retardation”, and “fetal growth restriction”.

Results

We included 12 articles with data from a total of 6,713,596 people. Compared with non-SGA infants, infants small for gestation age (SGA) were not associated with an increased risk of asthma (OR = 1.07; 95% CI 0.94–1.21). However, in the subgroup analysis, we found an increased risk of later onset asthma among SGA in studies conducted in Asia, with a large sample size, and defined asthma through medical records rather than questionnaires. Large for gestational age (LGA) was not associated with an increased risk of asthma when non-LGA or appropriated for gestational age (AGA) infants were used as the reference (OR = 1.02; 95% CI 0.90–1.16; OR = 1.01; 95% CI 0.88–1.15).

Conclusion

These results indicated that neither SGA nor LGA was associated with an increased risk of asthma. However, considering the limitations of the research, these results should be interpreted with caution.

Association between active tobacco use during pregnancy and infant respiratory health: a systematic review and meta-analysis

OBJECTIVE

To evaluate what is known about active tobacco use during pregnancy and the association with infant respiratory health.

DESIGN

Systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

DATA SOURCES

MEDLINE, EMBASE, Cochrane, CINAHL, and Maternity and Infant Care were searched thoroughly until June 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included case-control and cohort studies estimating the association between active tobacco use during pregnancy and infant respiratory health (wheezing and apnoea) and lung function parameters in the first 12 months of life.

DATA EXTRACTION AND SYNTHESIS

Extraction and risk of bias assessment were conducted by two independent reviewers. The odds ratio, relative risk and mean differences were pooled with a 95% CI using the generic inverse variance method. Heterogeneity was assessed and expressed by percentage using I2.

RESULTS

We identified 4423 abstracts, and 21 publications met the eligibility criteria. Pooled OR showed an increase in wheezing episodes in infants born to mothers who were active tobacco users during pregnancy (OR 1.50, 95% CI 1.27 to 1.77, p<0.01). Mixed results were found on lung function parameters, and a meta-analysis including two studies with comparable methodology showed a trend towards reduced maximum flow rate at functional residual capacity of -34.59 mL/s (95% CI -72.81 to 3.63, p=0.08) in 1-month-old infants born to women who smoked during pregnancy. A higher risk of apnoea was described for infants born to mothers who used smokeless tobacco during pregnancy, while the results in infants born to women who actively smoked tobacco during pregnancy were non-conclusive.

CONCLUSION

Infants born to mothers who actively smoked during pregnancy are at higher odds of having wheeze and may have lower lung function. Smokeless tobacco use in pregnancy may increase the risk of apnoea in infancy.

PROSPERO REGISTRATION NUMBER

CRD42018083936.

Birth weight is not causally associated with adult asthma: results from instrumental variable analyses

The association between lower birth weight and childhood asthma is well established. However, it remains unclear whether the influence of lower birth weight on asthma can persist into adulthood. We conducted a Mendelian randomization analysis to assess the causal relationship of birth weight (~140,000 individuals) on the risk of adult asthma (~62,000 individuals). We estimated the causal effect of birth weight to be 1.00 (95% CI 0.98~1.03, p = 0.737) using the genetic risk score method. We did not observe nonlinear relationship or gender difference for the estimated causal effect. With the inverse-variance weighted method, the causal effect of birth weight on adult asthma was estimated to be 1.02 (95% CI 0.84~1.24, p = 0.813). Additionally, the iMAP method provides no additional genome-wide evidence supporting the causal effects of birth weight on adult asthma. Our results were robust against various sensitivity analyses, and MR-PRESSO and MR-Egger regression showed that no instrument outliers and no horizontal pleiotropy were likely to bias the results. Overall, our study provides no evidence for the fetal origins of diseases hypothesis for adult asthma, implying that the impact of birth weight on asthma in years of children and adolescents does not persist into adult and previous findings may be biased by confounders.

Large for gestational age and macrosomia in pregnancies without gestational diabetes mellitus

Objective: This study aims to estimate the prevalence and risk factors of macrosomia and LGA (large for gestational age) in non-GDM (gestational diabetes mellitus) pregnant women in Fuyang, Anhui Province of China.Methods: A large population-based cohort study was conducted among non-GDM pregnant women aged 18-45 years. Maternal sociodemographic data prior to pregnancy were collected using interviewer-administered standardized questionnaire. Maternal obstetrical delivery records and newborn hospital records were extracted from antenatal care booklets and hospital discharge abstracts. Logistic regression analysis was used to identify the predictors of macrosomia and LGA.Results: The incidence of macrosomia and LGA was 9.2 and 15.9%, respectively. Mothers ≥35 years of age (aOR 2.75, 95% CI 1.98, 3.80), male neonates (aOR 1.68, 95% CI 1.51, 1.89), overweight and obese (aOR 1.61, 95% CI 1.34, 1.92 and aOR 3.05, 95% CI 2.05, 4.56, respectively) were associated with increased risk of macrosomia. Compared with the less educated mothers, the educated mothers were more likely to have increased risk of macrosomia. IFA (iron and folic acid) supplements intake during pregnancy was more likely to deliver macrosomia or LGA (aOR1.32, 95% CI 1.08, 1.49 and aOR1.42, 95% CI 1.24, 1.61, respectively) as compared with no IFA supplements intake. SCr (serum creatinine concentration) >80 µmol/L was related to decreased risk of macrosomia (aOR 0.73, 95% CI 0.61, 0.86) and LGA (aOR 0.67, 95% CI 0.59, 0.77) as compared with normal range (44-80 µmol/L).Conclusions: There was a high prevalence of macrosomia and LGA in non-GDM pregnant women in China. Healthcare educations and reasonable body weight are necessary for pregnant women to prevent macrosomia and LGA. Pregnant women should be checked regularly and have the first prenatal visit as soon as possible.