Maternal asthma linked to adverse perinatal outcomes

Published online May 7, 2025

Maternal asthma is one of the widely occurring chronic conditions during pregnancy, impacting nearly 10% of women worldwide. Prior research has highlighted that asthma in expectant mothers not only contributes to the onset of asthma in their children but also elevates the risks associated with pregnancy outcomes, such as preterm birth, low birth weight, and increased rates of cesarean deliveries (C-sections). However, earlier studies primarily concentrated on asthma flare-ups and symptom management during pregnancy, with insufficient investigation into pre-existing factors like asthma phenotypes or medication usage.

In a recent publication in The Journal of Allergy and Clinical Immunology: In Practice, Moitra and colleagues analyzed nearly ten years of data (2009-2018) derived from the Alberta Pregnancy Birth Cohort involving over 434,000 pregnancies. The researchers paid special attention to pregnancies where mothers had asthma and compared them with those of mothers without the condition. The study assessed three primary outcomes: preterm birth, low birth weight, and C-sections. Additionally, the researchers categorized asthma by medication usage and by phenotype based on blood tests indicating inflammation levels to investigate if these variables correlate with adverse perinatal outcomes. The influence of prenatal education on these results was also examined.

The findings indicated that mothers with asthma faced a 15% increase in preterm birth, a 12% rise in the risk of low birth weight, and a 9% greater chance of requiring a C-section than those mothers without asthma. The study also revealed that asthmatic mothers exhibiting higher levels of blood neutrophils and eosinophils encountered increased risks of preterm birth and low birth weight. The type of asthma medication utilized was also a factor; mothers who used oral corticosteroids during pregnancy had a higher likelihood of complications, potentially linked to more severe or uncontrolled asthma. Furthermore, mothers who did not engage in prenatal education were at notably elevated risks of preterm birth and low birth weight compared to those who did participate. The study underscored the necessity of effective asthma management during pregnancy, encompassing early diagnosis, suitable treatment, and prenatal education, to mitigate risks for both mothers and their infants. 

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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