NEW YORK (Reuters Health) - Maintaining allergen-specific immunotherapy (AIT) during pregnancy shows no evidence of raising the risk of congenital malformations or other adverse pregnancy outcomes, according to a nationwide study from Sweden.
Although a few earlier studies evaluating AIT in pregnant women have come to similar conclusions, they were small "and guidelines continue to recommend against initiating AIT during pregnancy," researchers note in the Journal of Allergy and Clinical Immunology: In Practice.
To learn more, Dr. Niki Mitselou of Orebro University Hospital and her colleagues extracted data from Swedish national health registries on more than 900,000 singleton live-birth pregnancies between 2005 and 2014.
Sublingual immunotherapy to treat grass pollen seasonal allergy was introduced in Sweden in 2005. Dr. Mitselou noted that starting AIT during pregnancy would have been discouraged during the study period, while maintaining well-tolerated AIT would have been be encouraged.
The decision to treat women of child-bearing age with AIT would have depended on whether "the patient herself had plans of getting pregnant soon, with the risk that this coincides with the AIT induction phase," Dr. Mitselou told Reuters Health.
Of the overall cohort, 743 pregnant women had a record of exposure to AIT three months before conception until gestational week 22.
