Allergen immunotherapy in pregnancy.

Background: Allergic diseases such as asthma and allergic rhinitis constitute asignificant burden of disease among women of childbearing age and those who arepregnant. Adequately managing these conditions is paramount in reducing negativefetal outcomes as well as maternal complications during pregnancy. However, thepotential for harm to both the mother and fetus demands carefully balancing efficacyand safety of treatment. Allergen immunotherapy (AIT) has emerged as a relativelysafe and efficacious mode of therapy in both children and adults. AIT has also beenconsidered for use during pregnancy. Methods: A review of the literature wasconducted for data regarding the safety of initiation and continuation of AIT duringpregnancy as well as the effect of AIT on the development of atopy in offspring. MEDLINE and the Cochrane Library were searched for clinical trials, randomizedcontrol trials, observational studies and journal articles in English using the terms"Pregnancy" and "Immunotherapy" from 1900 to present. This yielded 4 studies(totaling 422 pregnancies receiving AIT) investigating the continuation of AIT inpregnancy, 2 (totaling 31 pregnancies receiving AIT) evaluating AIT initiation duringpregnancy and 5 observing the effect of AIT on atopy in offspring. Results: No significant difference was found in the incidence of prematurity, hypertension (HTN)/proteinuria, congenital malformations or perinatal deaths betweenthe women continued on AIT (both subcutaneous (SC) IT and sublingual (SL) IT toinhalant allergens as well as venom IT) during pregnancy and controls. Similarly, therewas no significant difference in maternal or fetal complications between pregnantwomen initiated on AIT and controls. Among the few pregnant women (10/453pregnancies) who experienced generalized reactions while receiving AIT, none werefound to have fetal complications. Neither SCIT nor SLIT during pregnancy altered therisk of developing atopic disease in offspring. Conclusions: Based on these data, the continuation of AIT during pregnancyappears safe. Furthermore, the few data available suggest that the initiation of AITduring pregnancy might also be safe, however, more data is required for a definitiveconclusion. Lastly, available studies do not show a convincing reduction in thedevelopment of atopy in offspring from the administration of AIT during pregnancy. [ABSTRACT FROM AUTHOR]