Small for gestational age (SGA)
Definition
Small for gestational age means that a fetus or an infant is smaller or less developed than normal for the baby's sex and 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.
Alternative Names
Low birth weight
Information
Ultrasound is used to find out if a fetus is smaller than normal for their age. This condition is called intrauterine growth restriction. The most common definition of small for gestational age (SGA) is a birth weight that is below the 10th percentile. At the time of the ultrasound exam, your health care provider may use other findings, such as the amount of amniotic fluid surrounding the baby, to further understand the baby's condition.
Causes for SGA fetus may include:
- Genetic diseases
- Inherited metabolic diseases
- Chromosome anomalies
- Multiple gestations (twins, triplets, and more)
- Abnormal placenta
- High blood pressure
A developing baby with intrauterine growth restriction will be small in size and can have problems such as:
- Increased red blood cells
- Low blood sugar
- Low body temperature
References
Baschat AA, Galan HL. Intrauterine growth restriction. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics Essentials: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 33.
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:8/23/2023
Reviewed 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.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.
Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.
Health Outcome Data
No data available for this condition/procedure.