Choi SKY, et al. - Using the Australian National Perinatal Data Collection, researchers conducted this population-based cohort study to ascertain if infant mortality and morbidity, and the categorisation of infants as small for gestational age or large for gestational age (SGA or LGA) vary by maternal country of birth, as well as to evaluate if the choice of growth chart alters the risk of adverse outcomes in infants categorised as SGA and LGA. A population cohort of 601,299 singleton infants born to immigrant mothers in Australia was contrasted with 1.7 million infants born to Australian-born mothers, 2004–2013. In comparison to Australian-born infants, infants of mothers from Africa, Philippines, India, other Asia countries, and the Middle East had between 15.4% and 48.1% higher risk for stillbirth, preterm delivery, or low Apgar score. The connection between SGA and LGA and perinatal mortality differed significantly through the growth chart and birth country. Country-of-birth-specific variations are becoming increasingly important to provide maternity care that is ethnically appropriate and safe. The results show important differences in the risk of negative perinatal results in immigrant subgroups and show how growth chart selection changes the risk quantification connected with the birth of SGA or LGA.