Investigating Maternal Asthma's Impact on Prenatal and Neonatal Health

Women with asthma face a 15 per cent higher risk of preterm birth (PTB), a 12 per cent higher risk of low birth weight (LBW), and a 9 per cent higher likelihood of undergoing Caesarean sections. Additionally, lack of prenatal education among first-time mothers with asthma showed that they were 82 per cent more likely to deliver preterm and 83 per cent more likely to have a low-birth-weight baby than their non-asthmatic counterparts.

The findings emerging from the study of Subhabrata Moitra, Assistant Professor at Ahmedabad University's Bagchi School of Public Health​​​​​​, drew upon a national pregnancy cohort in Canada, examining more than 4,30,000 pregnancies. Women were classified into various asthma categories (current, past, and active) and phenotype groups based on blood markers (eosinophils and neutrophils), and by their medication regimens.

What makes this study novel is the introduction of asthma phenotyping, to the analysis. The research revealed that women with high counts of specific white blood cells, eosinophils and neutrophils (HBE/HBN phenotype), faced the highest risk for adverse birth outcomes. These blood-based indicators could be crucial for customising treatment strategies during pregnancy. What's equally concerning is that urban women with asthma were more likely to experience adverse birth outcomes compared to their rural counterparts. Although the authors could not explicitly identify the reason for such, one can point out the roles of different sociodemographic, environmental, and mental health determinants that might play vital roles. Additionally, asthma medications also had a role in the adverse perinatal outcomes; pregnant women with asthma using oral corticosteroids were at the highest risk for PTB and LBW than those without asthma. Even women who had asthma but were not on medication had a higher risk of adverse perinatal outcomes than their non-asthmatic counterparts.

"Although the data were from Canada, maternal asthma is a worldwide issue, and all aspects studied in that paper also apply to Indian patients, thus signifying the generalisability of the study findings," said Professor Moitra.

Asthma contributes to poor perinatal outcomes, including foetal hypoxia (due to compromised lung function), which contributes to intrauterine growth restriction and low birth weight (LBW). Additionally, the persistent inflammation linked to asthma may increase the risk of preterm birth (PTB). Asthma-related bronchoconstriction can worsen maternal hypertension, and asthma exacerbations place physiological stress on the mother, further contributing to adverse perinatal outcomes.

The study, conducted in collaboration with researchers from the University of Alberta, the University of Calgary, the Barcelona Institute for Global Health, and the University of Montpellier, strongly advocates for customised and personalised care, including medication, education, and phenotype-based asthma control strategies during pregnancy.

The study, Maternal Asthma and Adverse Perinatal Outcomes: An Analysis of 434,068 Pregnancies in Canada, was published in the Journal of Allergy and Clinical Immunology: In Practice, an official publication of the American Academy of Allergy, Asthma and Immunology (AAAAI).

The study proposes an interdisciplinary approach that requires healthcare professionals, researchers, and educators to converge their asthma management strategies. Early diagnosis and proper classification of asthma are crucial for healthcare professionals to create effective management plans. These strategies, coupled with prenatal education modules, could lower the risk of complications for newborns. Additionally, the study calls for medical experts to reevaluate the use of certain asthma medications, like oral corticosteroids (OCS), during pregnancy to find steroid-sparing alternatives.