Maternal asthma medication associated with premature birth, low birth weight

Asthma medication prescription before or during pregnancy was associated with a higher prevalence of premature birth and lower birth weight among infants, particularly if medication was discontinued during pregnancy, researchers reported.

“This analysis of prescription records for over 100,000 pregnancies found that women who stopped their asthma medicines during pregnancy were at increased risk of preterm birth and not breastfeeding at 6-8 weeks, whereas women who continued with their inhaled corticosteroids were at lower risk. Prescription records could be used to identify the women who need extra help and support,” Gareth Davies, PhD, associate professor in the department of health and life science at Swansea University, U.K., and colleagues said in a press release.

The population-based cohort study included 110,727 individuals born from 2000 to 2010 in Wales with data on premature birth, small gestational age and breastfeeding. Researchers evaluated the association between these adverse birth outcomes and linked maternal asthma prescription and discontinuation information.

The primary outcomes were premature birth (premature, < 37 completed weeks’ gestation; very premature, < 32 completed weeks’ gestation), growth centiles for infants below the 10th and third percentiles defined from WHO standards, and breastfeeding routinely recorded by health visitors at birth and 6 to 8 weeks.

Asthma medication prescriptions were associated with premature birth at less than 32 weeks’ gestation (adjusted OR = 1.33; 95% CI, 1.09-1.61), small gestational age less than 10th centile (aOR = 1.1; 95% CI, 1.03-1.18) and no breastfeeding (aOR = 0.93; 95% CI, 0.87-1.01) whether continued or discontinued during pregnancy, researchers wrote. Asthma medication prescription discontinuation was associated with birth at less than 37 weeks’ gestation (aOR = 1.22; 95% CI, 1.06-1.41) and less than 32 weeks’ gestation (aOR = 1.53; 95% CI, 1.11-2.1), according to the results.

Researchers observed an association with small gestational age less than the 10th percentile with all asthma medications, except inhaled corticosteroids and short-acting beta agonists prescribed alone.

Along with lower breastfeeding rates, these results highlight the related unmet needs among women who discontinue asthma medication prescriptions and aid in mitigating against medication reduction during pregnancy, according to the researchers.

“Reduced risks with inhaled corticosteroids suggest that increased monitoring, targeted support and active asthma management are needed before, during and after pregnancy,” the researchers wrote. “Programming primary care electronic records to alert professionals to contact women who leave greater than 4 months between prescriptions for asthma medications might make this feasible.”