Objectives: To assess the associations of asthma severity, exacerbations, and medication use with adverse perinatal outcomes (preterm delivery (PD), low birth weight (LBW), and small for gestational age (SGA)).
Methods: Two English databases (PubMed and Embase) and two Chinese databases (Wanfang and CNKI) were searched to retrieve cohort studies published up to 1st January 2021 which compared the odds of adverse perinatal outcomes in groups of asthmatic women stratified by asthma severity, asthma exacerbations or medication use, or compared the odds of adverse perinatal outcomes between non-asthmatic women and asthmatics of various levels of severity and exacerbation. Random-effects models were used to calculate pooled odds ratio (OR) and 95% confidence interval (CI).
Results: Twenty studies met the inclusion criteria. The odds of delivering SGA babies increased with maternal asthma severity. Pregnant women with an asthma exacerbation had higher odds of delivering LBW babies and SGA babies, compared to pregnant women with asthma but without an exacerbation (OR: 1.15, 95% CI: 1.02, 1.29 for LBW, and OR: 1.13, 95% CI: 1.04, 1.23 for SGA) and compared to pregnant women without asthma (OR: 1.56, 95% CI: 1.21, 2.02 for LBW and OR: 1.41, 95% CI: 1.18, 1.68 for SGA). Oral corticosteroids use during pregnancy was associated with increased odds of LBW, but not PD.
Conclusions: The available data suggest that maternal asthma severity and exacerbations are associated with increased odds of LBW and SGA babies. Future well-designed studies exploring if asthma medication use increases the odds of adverse perinatal outcomes are merited.