DefinitionLarge for gestational age (LGA) means that a fetus or infant is larger or more developed than normal for the baby's gestational age.InformationGestational age is a measure of the growth and development of the fetus in the uterus and the infant after birth. LGA refers to a fetus or infant who is larger than expected for the age and gender or with a birth weight above the 90th percentile.The measurement is based on the estimated gestational age of the fetus or infant, compared with what is considered normal height, weight, head size, and developmental level for a fetus or infant of the same age and gender.Common causes of a fetus or infant who is large for gestational age are:Gestational DiabetesProlonged pregnancyA baby that is large for gestational age has a higher risk of birth