[Effect of early-life antibiotic exposure on allergic symptoms in children aged 6-11 months and 18-23 months based a birth cohort study].

Objective: To analyze the associations between prenatal and 1-year-old exposure to antibiotics and allergic symptoms in children aged 6-11 months and 18-23 months. Methods: In this study, a prospective birth cohort study was adopted. A total of 2 122 pregnant women were enrolled in Maternal and Child Health Care Center of Ma'anshan from June 2015 to June 2016, and they were followed up from the beginning of pregnancy to children's 24 months of age. Excluding 564 pairs of mothers and children who were lost to follow-up or with incomplete information on the use of antibiotics and children's allergic symptoms, a total of 1 558 pairs of mothers and children were included in the analysis of this study. The parents and children's general demographic information, early-life antibiotic exposure and other data were collected, the information about allergic symptoms in children aged 6-11 months and 18-23 months were investigated by reference to the "International Study of Asthma and Allergies in Childhood (ISAAC)". The univariate and multivariate binary unconditional logistic regression model was used to was used to estimate associations between the effects of early-life antibiotic exposure on allergic symptoms in 2-year-old children. Results: The antibiotic usage rate of pregnant women during pregnancy was 3.4% (53), and the antibiotic usage rates of children between 0 to 2 months, 3 to 5 months, and 6 to 11 months were separately 15.2%(237), 15.5%(242) and 17.3%(269). The total prevalence of allergic diseases in children aged 6 to 11 months was 24.1% (375 children), and the total prevalence of allergic diseases in children aged 18 to 23 months was 22.0% (342 children). After adjust parental (maternal) education level, family monthly income per capita, parental (maternal) allergy history, parental (maternal) age at pregnancy, mother's Body Mass Index (BMI) before pregnancy, exposure to second-hand smoke during pregnancy, delivery method, child gender, birth weight, preterm birth, the use of antibiotics when children were 3-5 months old (RR=1.61,95%CI:1.19-2.17) and 6-11 months old (RR=1.43,95%CI:1.06-1.93) were the risk factors for allergic symptoms at 6-11 months of age; and the use of antibiotics when children were 0-2 months old (RR=1.41, 95%CI: 1.03-1.95), 3-5 months old (RR=1.54, 95%CI: 1.12-2.11) and 6-11 months old (RR=1.58, 95%CI: 1.17-2.14) were the risk factors for allergic symptoms at 18-23 months of age. Conclusion: Children's exposure to antibiotics within 1 year of age was a risk factor for allergic symptoms in children aged 6-11 months and 18-23 months, children should avoid unnecessary antibiotic use in infancy.