Is FGR the Same as IUGR?

Medically Reviewed on 3/25/2022

What is fetal growth restriction?

Is FGR same as IUGR
Fetal growth restriction (FGR) is the same as intrauterine growth restriction (IUGR).

Yes, fetal growth restriction (FGR) is the same as intrauterine growth restriction (IUGR)

The term IUGR is now replaced by FGR; however, they are the same.

  • It is a condition in which an unborn baby (fetus) is smaller in size than expected for the number of weeks of pregnancy (gestational age).
  • To be specific, the estimated weight of the fetus is less than the 10th percentile. Also referred to as “small for gestational age,” it means that the baby weighs less than 90 percent of babies of the same gestational age.

What causes FGR?

Many factors can increase the risk for fetal growth restriction (FGR). These include problems with the placenta or umbilical cord and certain factors in the mother and baby. The placenta is the organ that is formed during the pregnancy, and it carries oxygen and nutrients to the baby. There may be problems with the attachment of the placenta to the uterus or restricted blood flow through the umbilical cord.

Factors in the mother that can cause FGR to include:

Factors in the baby that can cause FGR to include:

  • Multiple gestations (being one of the twins, triplets, or more)
  • Infections
  • Congenital problems or birth defects (such as heart defects)
  • Problem with genes or chromosomes


The first sign of pregnancy is most often: See Answer

How is FGR diagnosed?

Fetal growth restriction (FGR) is diagnosed during regular prenatal checkups.

The simplest way for the doctor to find is by checking the fundal height. To check fundal height, the healthcare provider measures from the top of your pubic bone to the top of your uterus (fundus). Fundal height is measured in centimeters. After the 20th week, it is about the same as the number of weeks of pregnancy.

To confirm the diagnosis, your doctor may order diagnostic tests that include:

  • Fetal ultrasound: To estimate fetal weight, an ultrasound procedure uses sound waves that create images of the baby in the womb.
  • Doppler ultrasound: A special type of ultrasound to check the blood flow to the placenta and through the umbilical cord to the baby.
  • Fetal monitoring: Monitoring devices strapped over the uterus to record the baby’s heartbeat.
  • Amniocentesis: Drawing amniotic fluid from the womb to check for any infections or genetic abnormalities.

How is FGR treated?

Your doctor will treat fetal growth restriction (FGR) depending on the underlying cause and its severity, which is estimated from the diagnostic tests.

First, you will be asked to have frequent prenatal visits, ultrasound, and Doppler ultrasound exams, and other tests, if needed.

  • If maternal conditions, such as high blood pressure is responsible for FGR, your doctor will treat you to lower the blood pressure.
  • If infections are causing the condition, appropriate medications may be administered to treat them.

Your doctor may ask you to keep track of fetal movements. If you find a decrease in the movements, you need to contact the doctor right away.

You may have early delivery or emergency cesarean to avoid complications in the baby after the delivery.

How can FGR be prevented?

Fetal growth restriction (FGR) can occur in any pregnancy. However, you can lower your chances of developing it by avoiding cigarette smoking, alcohol, or recreational drug use. Having regular and early prenatal care, following a healthy diet, managing blood pressure, and appropriate weight gain can help prevent FGR.

Medically Reviewed on 3/25/2022
Image Source: iStock Images

Ross MG. Fetal Growth Restriction. Medscape.