Large for gestational age means that a fetus or infant is larger or more developed than normal for the baby's gestational age. Gestational age is the age of a fetus or baby that starts on the first day of the mother's last menstrual period.
Large for gestational age (LGA) refers to a fetus or infant who is larger than expected for their age and gender. It can also include infants with a birth weight above the 90th percentile.
The LGA measurement is based on the estimated gestational age of the fetus or infant. Their actual measurements are compared with normal height, weight, head size, and development of a fetus or infant of the same age and sex.
Before birth LGA measurements are obtained by ultrasound exam. In an ultrasound exam obtained close to term, the exam is not as accurate and may suggest LGA in some cases where the baby is growing normally. You should talk with your provider about this issue.
Common causes of the condition are:
- Gestational diabetes
- Obese pregnant mother
- Excessive weight gain during pregnancy
A baby that is LGA has a higher risk for birth injury. There is also a risk for complications of low blood sugar after delivery if the mother has diabetes.
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Cooke DW, DiVall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 25.
Suhrie KR, Tabbah SM. High-risk pregnancies. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 114.
Review Date 7/13/2021
Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.