The registry includes prospectively collected data such as sex, gestational age, gestation and perinatal information, mother's and infant's ABO group and Rh, G6PD deficiency, Coombs test, type of delivery and complications, birthweight, postnatal medications and interventions, type and volume of feeding (daily), extension of jaundice, TcB measurements at intervals of 12+/-4 hours until discharge, total serum bilirubin values (if obtained), TcB or TSB measurements at follow-up, weight at discharge, need of phototherapy (inpatient or after discharge). TcB and TSB values are plotted on a hour-specific chart.