Background

Early life factors are associated with allergic respiratory diseases, but the role of high grass pollen concentrations during pregnancy and shortly after birth is not known.

Objective

To assess outdoor levels of grass pollen during the intrauterine period and at birth during peak pollen season on cord blood IgE in birth cohorts.

Methods

Three birth cohorts were included: MACS (n = 429), Australia; COPSAC₂₀₀₀ (n = 200), Denmark; and LISA (n = 1968), Germany. Cord blood IgE was categorized (<0.5 kU/L, 0.5–1 kU/L, >1 kU/L) and dichotomized (high IgE ≥ 0.5 kU/L). Birth during the grass pollen season months and cumulative exposure to outdoor grass pollen counts during pregnancy with cord blood IgE were analysed using multinomial regression and analysed in meta-analysis using binomial regression adjusted for potential confounders.

Results

Birth during the grass pollen season had higher pooled odds of cord blood IgE >0.5 kU/L 1.37 (95% CI 1.06, 1.77) in a meta-analysis with little heterogeneity between the three cohorts. Cumulative exposure to outdoor grass pollen counts during the entire pregnancy was associated with slightly lower pooled odds but significant (OR = 0.98, 95% CI: 0.96 to 0.99).

Conclusions

Birth during grass pollen seasons were associated with increased risk of high cord blood IgE in cities from both hemispheres, but high pollen loads in the environment during the entire pregnancy appeared protective. As IgE responses develop during the first months of life, our study findings provide new insights into the mechanisms of grass pollen exposure at birth and shortly after on possible allergic respiratory diseases.

中文翻译：

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子宫内和出生时的环境草花粉水平以及脐带血IgE：三个出生队列的分析

背景

早期的生活因素与过敏性呼吸系统疾病有关，但怀孕期间和出生后不久的高草花粉浓度的作用尚不清楚。

客观的

评估出生队列中脐血IgE在宫内期和高峰花粉季节出生时的室外花粉水平。

方法

包括三个出生队列：MACS（n  = 429），澳大利亚；COPSAC ₂₀₀₀（n  = 200），丹麦；和LISA（n  = 1968），德国。脐带血IgE分为（<0.5 kU / L，0.5–1 kU / L，> 1 kU / L）和二分法（高IgE≥0.5 kU / L）。使用多项式回归分析了草花粉季节月份中的出生时间和脐带血IgE期间怀孕期间暴露于室外草花粉计数的累积量，并使用针对潜在混杂因素进行了调整的二项式回归进行了荟萃分析。

结果

在荟萃分析中，草花粉季节出生的脐血IgE> 0.5 kU / L 1.37（95％CI 1.06，1.77）的合并几率更高，三个队列之间几乎没有异质性。在整个怀孕期间，累计暴露于室外草粉花粉的机会与合并几率稍低但显着相关（OR = 0.98，95％CI：0.96至0.99）。

结论

在两个半球城市中，花粉季节出生的人与脐带血高IgE的风险增加有关，但整个妊娠期间环境中的高花粉负荷似乎是有保护作用的。随着IgE反应在生命的头几个月中发展，我们的研究结果为出生时以及可能出现过敏性呼吸道疾病后不久接触草花粉的机制提供了新见解。