Fig. 1

Flowchart of subject selection. Of the 104,065 fetuses that were registered in the JECS, stillbirths, abortions, and those who were not followed up were excluded, and 100,144 live births were finally registered. Then, 83,662 infants who met the following conditions—full-term birth, single birth, and no congenital disease—were considered. The congenital diseases excluded were chromosomal anomalies and anomalies of the head or brain. After excluding infants with missing data regarding surgery under general anesthesia or any J-ASQ-3 domains and who were not within the applicable assessment age for the J-ASQ-3, the final study population included 64,141 infants