Intrauterine Growth Restriction: What You Need to Know

    Published 03 June 2020
    Fact Checked
    Reviewed by Olga Adereyko, MD, Primary Care Physician, General Practitioner, Medical Consultant
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    Intrauterine growth restriction is a slower-than-average development rate, which means your baby is smaller than expected for their gestational age. It could result in health complications during labor and later in life. Below, find everything you need to know about IUGR in pregnancy.

    What is intrauterine growth restriction?

    Also known as fetal growth restriction (FGR), intrauterine growth restriction means that your fetus isn’t growing at the predicted rate. IUGR may occur at any point in your pregnancy, causing your newborn to be considered “small for gestational age.” Compared to other babies at the same stage of life, their estimated weight doesn’t quite reach the 10th percentile.

    Unfortunately, this increases their likelihood of a variety of medical complications. They might experience lower oxygen levels in the womb, which affects organ development. Following delivery, their low birth weight puts them at greater risk for infection or disease. Potential long-term issues include metabolic syndrome, type 2 diabetes, heart disease, and growth difficulties.

    However, not every child who is born tiny is going to experience health problems. Your doctor will closely monitor each aspect of your pregnancy to help ensure everything stays on track. 

    Ways to diagnose IUGR

    You’ll have regular prenatal exams in which your doctor manually measures the expansion of your uterus by checking the fundal height, which is the distance from the top of your uterus to the top of your pelvic bone. A general rule is that the fundal height in centimeters should be equivalent to your gestation week (after week 20). So if you’re in the 22nd week of pregnancy, the fundal height ought to be roughly 22 centimeters. 

    But if your uterus is consistently falling short of this average, then your doctor may order ultrasound exams to determine if you’re experiencing intrauterine growth restriction.

    In a fetal ultrasound for IUGR, your baby’s size and weight are estimated. (Note that the sound waves utilized in these exams will not harm them in any way.) Fetal growth restriction is then diagnosed based on collected measurements, which are compared to average growth rates at their gestational age.

    Additionally, your doctor could suggest a Doppler ultrasound to examine the placenta, umbilical cord, and blood flow. Lower than normal blood flow often indicates FGR. If you’ve been diagnosed with intrauterine growth restriction, you’ll likely be scheduled for regular ultrasounds to monitor your child’s ongoing development.

    Causes of IUGR

    An inadequate supply of nutrients, oxygen, and blood through the placenta can up your baby’s chances of intrauterine growth restriction. Poor prenatal care is another culprit behind IUGR. Other contributing factors include:

    • Maternal high blood pressure or heart disease

    The extra work your heart is doing to process the excess amount of blood in your body during pregnancy might hamper blood flow to your placenta.

    Type 1, type 2, and gestational diabetes are capable of creating placental abnormalities.

    • Chronic lung or kidney diseases
    • Being underweight 
    • Anemia

    A shortage of red blood cells translates to a lack of oxygen being delivered to your fetus.

    • Autoimmune diseases
    • Poor nutrition or insufficient weight gain

    As your pregnancy progresses, you should be putting on a certain number of pounds in order to maintain your little one’s overall health.

    • Obesity

    Being overweight can produce numerous medical complications.

    • Drinking or smoking

    Alcohol consumption is responsible for fetal alcohol syndrome, speech problems, and developmental delays. Smokers, on the other hand, tend to supply inadequate amounts of oxygen to their babies. Furthermore, nicotine and other chemicals found in cigarettes are clearly detrimental to them.

    • Drug use

    Controlled substances and some prescription medications could negatively impact the health of your fetus. It’s critical to be honest with your doctor so they can properly manage underlying conditions and keep your child safe.

    Certain circumstances naturally lead to intrauterine growth restriction. They include:

    • Multiple babies

    Being a twin or a triplet and sharing resources in the womb is tricky. One baby might receive more than the other(s), or they could all be born at a lower-than-average birth weight.

    • Infections 

    Rubella, cytomegalovirus, and genital herpes have the potential to trigger pregnancy complications. Consult your doctor if you haven’t gotten the MMR (measles, mumps, and rubella) vaccine. Also, if you often suffer from cold sores or carry herpes, please discuss ways to prevent transmitting the infection to your newborn.

    • Birth defects (especially of the heart)
    • Genetic predispositions or chromosomal abnormalities

    How to prevent IUGR

    Intrauterine growth restriction is a possibility for any expectant mother, but proper prenatal care and healthy lifestyle choices go a long way toward protecting your baby. 

    Avoid smoking, drinking, and drug use while pregnant, and try to take the preventative measures listed above. By understanding the common causes of intrauterine growth restriction, you can help stack the odds in your newborn’s favor.

    Management and treatment of IUGR

    Treatment of intrauterine growth restriction depends on the nature of your condition, current lifestyle, and stage of pregnancy. FGR severity is determined with either a prenatal ultrasound or Doppler ultrasound of the placenta. 

    Routine doctor visits and ultrasound examinations are a big part of managing intrauterine growth restriction to keep a close eye on fetal development. You might also need to track your baby’s movements and kicking, but check with your doctor for specific instructions. 

    Severe cases of IUGR might require hospitalization or bed rest, in addition to corticosteroid medications. In some instances, you’ll be induced early or undergo a C-section to allow your child’s condition to be addressed immediately.


    Intrauterine growth restriction sometimes leads to fetal distress during delivery and medical issues later in life. Fortunately, this is not always the case. But if you’ve been diagnosed with IUGR, work closely with your doctor to maintain the healthiest pregnancy possible.

    History of updates

    Current version (03 June 2020)

    Reviewed by Olga Adereyko, MD, Primary Care Physician, General Practitioner, Medical Consultant

    Published (03 June 2020)

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