Association between frozen embryo transfer and childhood allergy: a retrospective cohort study

Abstract

Research questionDoes frozen embryo transfer (FET) elevate the risk of allergic diseases in offspring? DesignIn this study, we followed up 653 singleton children, including 166 children born through FET and 487 children born through natural conception (NC). Demographic characteristics, perinatal information and allergic diseases of children and their parents were collected through clinical medical systems and questionnaires. Furthermore, among these 653 children, allergen-specific IgE testing was performed using peripheral blood samples collected from 207 children, including 62 children in the NC group and 145 children in the FET group. The prevalence rates of allergic diseases and the positive rates of allergen-specific IgE testing were compared between FET and NC groups with adjustments for confounding factors. ResultsResults showed that children born from FET had a significantly elevated prevalence rate of food allergy (aOR=3.154, 95% CI:1.895-5.250, p<0.001). Align with this, the positive rates of food allergen sensitization were also increased (aOR=5.767, 95%CI: 2.859-11.751, p<0.001). In addition, FET children exhibited a higher positive sensitization rate to at least one allergen compared to NC children (aOR=3.127, 95%CI: 1.640-5.961, p<0.001). No association was observed between FET and other allergic diseases, including asthma (p=0.136), atopic dermatitis (AD) (p=0.130) and allergic rhinitis (AR) (p=0.922). Also, allergen-sensitization IgE testing indicated no differences between FET and NC children in the positive rates of other common allergens, including animals and insects allergens (p=0.627), inhaled outdoor allergens (p=0.915), and inhaled outdoor allergens (p=0.544). ConclusionOur study suggested that children born from FET had an increased risk of developing food allergies in early childhood.