Maternal Asthma Medication Linked to Premature Birth, Low Birth Weight in Infants

Sarfaroj Khan 


December 15, 2020



  • Prescription of asthma medicines before or during pregnancy was associated with premature birth and lower birth weight among infants, particularly if medication was discontinued during pregnancy.

Why this matters

  • Findings suggest that increased monitoring, targeted support and active asthma management are needed before, during and after pregnancy.

Study design

  • This population-based study included 110,727 infants born from 2000 to 2010 with data on premature birth, small for gestational age (SGA) and breastfeeding from the Secure Anonymised Information Linkage (SAIL) databank in Wales.

  • Associations between prescriptions for asthma medicines during pregnancy and their discontinuation in pregnancy and preterm birth (<37 or <32 weeks), SGA (<10th and <3rd centiles) and breastfeeding at 6-8 weeks were assessed.

  • Funding: None.

Key results

  • Prescriptions for asthma were associated with:

    • birth at <32 weeks’ gestation (aOR, 1.33; 95% CI, 1.10-1.61);

    • SGA <10th centile (aOR, 1.10; 95% CI, 1.03-1.18); and

    • no breastfeeding (aOR, 0.93; 95% CI, 0.87-1.01).

  • Discontinuation of asthma medicine during pregnancy was associated with birth at <37 weeks’ (aOR, 1.22; 95% CI, 1.06-1.41) and <32 week’s gestation (aOR, 1.53; 95% CI, 1.11-2.10).

  • Stillbirth was also more prevalent in women prescribed asthma medicines vs unexposed population (aOR, 1.56; 95% CI, 1.21-2.00), particularly if the medicines had been discontinued during pregnancy (aOR, 1.91; 95% CI, 1.29-2.82).

  • All asthma medicines examined, except inhaled corticosteroids-only or short-acting beta-2-agonists-only, were associated with an increased prevalence of SGA <10th centile.


  • Risk of bias.


Davies G, Jordan S, Thayer D, Tucker D, Humphreys I. Medicines prescribed for asthma, discontinuation and perinatal outcomes, including breastfeeding: A population cohort analysis. PLoS One. 2020;15(12):e0242489. doi: 10.1371/journal.pone.0242489. PMID: 33296383 View full text

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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