Fig. 2.

Association of general anesthesia ≥ once (A), only once (B), and ≥ 2 times (C) before 1 year of age with neurodevelopmental delay in children (n = 69,653). Adjusted odds ratios and 95% confidence intervals (CIs) for neurodevelopmental delay from the age of 12 to 48 months in each domain of the Japanese translation of the Ages and Stages Questionnaire (Third Edition) versus children who did not receive general anesthesia before age 1. Adjusted for maternal age at delivery, body mass index before pregnancy, marital status, smoking status, early pregnancy occupational status, educational background, annual household income, fetal sex, gestational age at birth, use of any medication before and during pregnancy, mode of delivery, presence or absence of epidural analgesia, birth weight, presence or absence of nursery school attendance at 6 and 12 months of age, breastfeeding method during the first 6 months of life, and presence or absence of cohabiting siblings. A multiple imputation method was used to reduce potential selection bias from missing variables. For communication delay at 12 months, the adjusted odds ratio could not be calculated due to the small number of participants with a score below the cutoff value