This study investigates the association between early exposure to anesthesia and the development of learning disabilities (LD) in a population-based birth cohort. The researchers analyzed data from children born in Olmsted County, Minnesota, from 1976 to 1982, focusing on those who remained in the community at age 5 years. They identified 5,557 children, of whom 593 had received general anesthesia before age 4 years. The study used Cox proportional hazards regression to calculate hazard ratios for anesthetic exposure as a predictor of LD, adjusting for factors such as gestational age, sex, and birth weight. Key findings include: - A single exposure to anesthesia was not associated with an increased risk of LD. - Children exposed to two or more anesthetics had a significantly increased risk of LD (hazard ratio = 1.59 for two exposures, 2.60 for three or more exposures). - The risk for LD increased with longer cumulative duration of anesthesia exposure. - The risk was not significantly different when excluding children with severe medical conditions. The study concludes that exposure to anesthesia before age 4 years is a significant risk factor for the later development of LD in children who receive multiple anesthetics, but it cannot determine whether anesthesia itself causes LD or if the need for anesthesia is a marker for other unidentified factors.This study investigates the association between early exposure to anesthesia and the development of learning disabilities (LD) in a population-based birth cohort. The researchers analyzed data from children born in Olmsted County, Minnesota, from 1976 to 1982, focusing on those who remained in the community at age 5 years. They identified 5,557 children, of whom 593 had received general anesthesia before age 4 years. The study used Cox proportional hazards regression to calculate hazard ratios for anesthetic exposure as a predictor of LD, adjusting for factors such as gestational age, sex, and birth weight. Key findings include: - A single exposure to anesthesia was not associated with an increased risk of LD. - Children exposed to two or more anesthetics had a significantly increased risk of LD (hazard ratio = 1.59 for two exposures, 2.60 for three or more exposures). - The risk for LD increased with longer cumulative duration of anesthesia exposure. - The risk was not significantly different when excluding children with severe medical conditions. The study concludes that exposure to anesthesia before age 4 years is a significant risk factor for the later development of LD in children who receive multiple anesthetics, but it cannot determine whether anesthesia itself causes LD or if the need for anesthesia is a marker for other unidentified factors.