Should we encourage allergen immunotherapy during pregnancy?

Primary prevention of allergy is a laudable goal, but one that has unfortunately proven difficult to achieve. Many different strategies have been reported to date, but unequivocal supporting data for any single strategy does not exist. Any successful strategy must lead to immunomodulation and must be encountered very early on life, likely in utero. Reports of early bacterial and farm animal exposures lend supportive data to the concept of immune regulation via early fetal exposure, howeve attempts at clinical applications of this, such as probiotics has not been completely successful. One practical, clinical method for achieving a similar immune modulation to these exposures would be providing atopic women with allergy immunotherapy while pregnant (or perhaps even preconception). Allergy immunotherapy is associated with favorable immune modulation and some data suggest that these changes if produced in mother can influence the atopic status of offspring.