Rationale Asthma in pregnancy is associated with respiratory diseases in the offspring. Objective To investigate if maternal asthma is associated with lung function in early life. Methods Data on lung function measured at 5–6 weeks of age were combined from two large birth cohorts: the Bern Infant Lung Development (BILD) and the Australian Breathing for Life Trial (BLT) birth cohorts conducted at three study sites (Bern, Switzerland; Newcastle and Sydney, Australia). The main outcome variable was time to reach peak tidal expiratory flow as a percentage of total expiratory time(tPTEF:tE%). Bayesian linear hierarchical regression analyses controlling for study site as random effect were performed to estimate the effect of maternal asthma on the main outcome, adjusting for sex, birth order, breast feeding, weight gain and gestational age. In separate adjusted Bayesian models an interaction between maternal asthma and sex was investigated by including an interaction term. Measurements and main results All 406 BLT infants were born to mothers with asthma in pregnancy, while 193 of the 213 (91%) BILD infants were born to mothers without asthma. A significant interaction between maternal asthma and male sex was negatively associated with tPTEF:tE% (intercept 37.5; estimate: –3.5; 95% credible interval –6.8 to –0.1). Comparing the model posterior probabilities provided decisive evidence in favour of an interaction between maternal asthma and male sex (Bayes factor 33.5). Conclusions Maternal asthma is associated with lower lung function in male babies, which may have lifelong implications on their lung function trajectories and future risk of wheezing and asthma. Data are available upon reasonable request.

中文翻译：

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在 BLT 和 BILD 队列的联合分析中，母体哮喘与男婴肺功能降低有关

基本原理 妊娠期哮喘与后代呼吸系统疾病有关。目的探讨母亲哮喘是否与生命早期的肺功能有关。方法 5-6 周龄时测量的肺功能数据来自两个大型出生队列：伯尔尼婴儿肺发育 (BILD) 和澳大利亚生命呼吸试验 (BLT) 出生队列，在三个研究地点（瑞士伯尔尼）进行；澳大利亚纽卡斯尔和悉尼）。主要结果变量是达到峰值潮气呼气流量的时间占总呼气时间的百分比（tPTEF：tE%）。进行贝叶斯线性分层回归分析，控制研究地点作为随机效应，以估计母体哮喘对主要结果的影响，调整性别、出生顺序、母乳喂养、体重增加和胎龄。在单独的调整贝叶斯模型中，通过包含交互项来研究母体哮喘与性别之间的交互作用。测量和主要结果 所有 406 名 BLT 婴儿的母亲均患有哮喘，而 213 名 (91%) BILD 婴儿中的 193 名 (91%) 婴儿的母亲未患有哮喘。母亲哮喘和男性之间的显着相互作用与 tPTEF:tE% 呈负相关（截距 37.5；估计值：–3.5；95% 可信区间 –6.8 至 –0.1）。比较模型后验概率提供了有利于母体哮喘和男性之间相互作用的决定性证据（贝叶斯因子 33.5）。结论 母亲哮喘与男婴肺功能降低有关，这可能对其肺功能轨迹和未来喘息和哮喘的风险产生终生影响。