Published Online: June 25, 2015
Asthma affects many women during pregnancy and asthma treatment guidelines highlight the importance of maintaining good asthma control during pregnancy, with inhaled corticosteroids (ICS) recommended as first line treatment. Pregnant women, however, are typically excluded from clinical trials and therefore evidence about the safety of many asthma medicines when used during pregnancy is sparse.
In an article recently published in The Journal of Allergy and Clinical Immunology: In Practice, Charlton and colleagues report on a study looking at the safety of the ICS fluticasone propionate (FP), when prescribed for the treatment of asthma during pregnancy. The researchers used data from the United Kingdom’s Clinical Practice Research Datalink, one of the world’s largest databases of anonymised longitudinal electronic medical records from primary care. The study compared the risk of a major congenital malformation (MCM) in the offspring of women who received a prescription for fluticasone propionate during the first trimester of pregnancy to the risk in the offspring of women who received a prescription for a different ICS during the same time period. The analyses were stratified by asthma treatment intensity level and took into account other factors which could have influenced the risk.
The study identified 5,362 pregnancies, during which the mother had received a prescription for an ICS during the first trimester of pregnancy and were eligible for the analysis of an MCM diagnosed by one year of age. The absolute risk of an MCM following any first trimester FP exposure was 2.4% (CI95 0.8-4.1) in women with a “moderate” asthma treatment intensity level and 2.7% (CI95 1.8-3.6) in women with a “considerable/severe” asthma treatment intensity level. When comparing the risk following FP exposure to the risk of a non-FP ICS, the authors found no evidence of an increased risk of major congenital malformations following exposure to FP during the early stages of pregnancy, with adjusted odds ratios of 1.1 (CI95 0.5-2.3) and 1.2 (CI95 0.7-2.0) for the “moderate” and “considerable/severe” intensity levels respectively. In addition, the risks following exposure to FP as monotherapy and FP in a fixed-dose combination with the long-acting β2-agonist salmeterol did not differ substantially.
The results of this study support the findings of previous studies evaluating the safety of other inhaled corticosteroids and provides reassurance to women and clinicians that inhaled fluticasone propionate is not a high-risk teratogen.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.