Large for gestational age (LGA)

Large for gestational age (LGA) refers to a fetus or infant who is larger than expected for their age and sex. 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 health care 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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Rozance PJ, Wright CJ. The neonate. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 9th ed. Philadelphia, PA: Elsevier; 2025:chap 25.

Triebwasser JE, Dolin CD. High-risk pregnancies. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 116.

Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 02/05/2025.