Small for Gestational Age

A baby who is small for gestational age (SGA) has a significantly lower weight than other babies of the same gestational age. Gestational age is the number of weeks into pregnancy.

  • Causes

    If parents have small stature, the baby may be small. These babies have normal development but are just small compared to others their age.

    SGA sometimes occurs if there are growth and development problems before birth. These may occur with:

    • Problems with the supply of nutrients and oxygen to the baby or a small uterus—can cause a condition known as intrauterine growth restriction (IUGR)
    • Birth defects
    • Genetic syndromes

  • Definition

    A baby who is small for gestational age (SGA) has a significantly lower weight than other babies of the same gestational age. Gestational age is the number of weeks into pregnancy.

    Newborn
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  • Diagnosis

    Your baby’s doctor will do a physical exam. A baby with SGA is often diagnosed before birth based on measurements taken of the mother’s abdomen, the mother’s weight, and ultrasound results. If the measurement is low for the number of weeks of pregnancy, then the baby may be smaller than average. SGA may also be diagnosed at birth based on the baby’s weight and height.

    Images may be taken during pregnancy with an ultrasound.

  • Prevention

    SGA due to family traits cannot be prevented.

    To help reduce your baby’s chance of getting SGA due to nutrition and oxygen problems during birth, take these steps during pregnancy:

    • If you smoke, quit.
    • If you use drugs or alcohol, ask your doctor to refer you to a treatment program that will help you stop.
    • Start prenatal care early and continue throughout pregnancy.

  • Risk Factors

    Parents with small stature increase the risk of SGA.

    Maternal factors that can affect a baby’s growth during pregnancy include:

    • High blood pressure
    • Smoking
    • Substance abuse
    • Excessive use of alcohol
    • Not taking folic acid supplements during pregnancy
    • A prior birth of a SGA baby
    • Chronic medical conditions, such as kidney failure, diabetes, asthma, lupus, or anemia
    • Previous bariatric surgery
    • Certain medications
    • Certain infections
    • Malnutrition
    • Silver-Russell syndrome

    Other factors that can affect baby’s growth include:

    • Pregnancy with more than 1 child
    • Birth defects
    • Genetic syndromes in the baby
    • Problems with the placenta, such as placental abruption or placenta previa

  • Symptoms

    Symptoms of SGA include a birth weight that is in the lowest 10% of babies with same gestational age.

  • Treatment

    Talk with your doctor about the best treatment plan for you. A baby with SGA is at higher risk for problems, such as difficulty feeding, blood sugar abnormalities, and breathing problems. The doctor will want to monitor your baby’s health and development closely.

    Babies that have SGA due to lack of nutrition or oxygen may need treatment. Options include: