Appropriate for gestational age (AGA) describes a fetus or newborn infant whose size is within the normal range for his or her gestational age.
Assigning size is a way to measure and monitor the growth of the infant throughout the pregnancy as well as at the time of birth.
The measurement is calculated based on the estimated gestational age (how many weeks the mother was pregnant) in comparison to what is considered normal height, weight, head size, and developmental level for a child of the same gestational age and gender.
Graphs are available showing the upper and lower normal limits for different gestational ages from the mid-20s through 42 weeks of gestation.
An appropriate for gestational age full-term infant is heavier than 2500 grams (about 5.5 lbs.) and lighter than about 4000 grams (about 8.75 lbs.).
Knowing the group into which an infant fits is important. An AGA baby tends to have the lowest risk for any problems. AGA babies have lower rates of disease and death than babies that are small or large for their gestational age.
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.