Desloratadine Use During Pregnancy and Risk of Adverse Fetal Outcomes: A Nationwide Cohort Study

Desloratadine is a frequently used drug for the treatment of allergic disorders, which often also require treatment during pregnancy. However, information on the fetal safety of desloratadine use during pregnancy is limited.

To investigate the association between desloratadine use during pregnancy and adverse fetal outcomes.

From a cohort of 1,287,668 pregnancies identified in the Danish nationwide registries in the study period 2001 to 2016, users of desloratadine and loratadine during pregnancy were matched in a 1:1 ratio based on propensity scores to compare the risk of adverse fetal outcomes. We compared the risk of the primary outcomes major birth defects (among a total of 3348 pregnancies) and spontaneous abortion (5498 pregnancies) and the secondary outcomes preterm birth (5280 pregnancies), small size for gestational age (SGA) for birth weight (5436 pregnancies), and stillbirth (6776 pregnancies). Logistic regression was used to estimate the prevalence odds ratio (OR) of major birth defects, preterm birth, and SGA, and Cox regression to estimate the hazard ratio (HR) of spontaneous abortion and stillbirth. Sensitivity analyses included comparing with cetirizine use in pregnancy and with pregnancies unexposed to desloratadine but with prior use as additional comparator groups.

Use of desloratadine in pregnancy was not associated with a significant increased risk of major birth defects (prevalence OR, 1.07; 95% confidence interval [CI], 0.77-1.50), spontaneous abortion (HR, 1.15; 95% CI, 0.96-1.37), preterm birth (prevalence OR, 0.84; 95% CI, 0.67-1.05), SGA (prevalence OR, 0.97; 95% CI, 0.80-1.16), or stillbirth (HR, 0.91; 95% CI, 0.31-2.70) compared with loratadine use in pregnancy. Sensitivity analyses, including those with the use of additional comparator groups, showed similar results.

Use of desloratadine during pregnancy was not associated with a statistically significant increased risk of adverse fetal outcomes as compared with loratadine. Results indicate that the fetal safety profile of desloratadine is similar to the currently recommended second-generation antihistamines during pregnancy.