Intrauterine Growth Restriction: Diagnosis, Monitoring and What to Expect

Reviewed by the RHC Health Desk. Last verified: August 27, 2026.

Medical Disclaimer: This page is for general education only. It is not medical advice, diagnosis, or treatment, and reading it does not create a provider-patient relationship. Talk with a licensed healthcare provider about your specific situation. If you are having a medical emergency, call 911 or go to the nearest emergency room. See our full Medical Disclaimer.

Intrauterine growth restriction (IUGR), also called fetal growth restriction, means a baby is growing more slowly than expected while still in the womb. It’s usually found when the baby’s estimated size falls below a certain point on a growth chart for that stage of pregnancy, or when the belly measures smaller than expected at a prenatal visit. It’s most often confirmed with an ultrasound.

Contact Your Provider Right Away If…

You notice your baby moving less than usual, at any point in pregnancy.
You’ve been told you may have a growth-restricted baby and you have new or worsening symptoms, such as reduced movement, vaginal bleeding, or severe swelling.
After birth, your baby doesn’t seem to be growing or developing as expected — call your provider then, too.

Don’t wait to see if movement picks up on its own. A same-day call to your provider or a trip to labor and delivery is the safe move.

What Can Cause Slower Fetal Growth

Growth restriction can come from problems with the placenta, the baby, or the mother’s health. Common contributors include:

Placenta problems that limit the oxygen and nutrients reaching the baby
Preeclampsia or eclampsia
Carrying twins, triplets, or more
Living at high altitude
Certain infections during pregnancy, including cytomegalovirus, rubella, syphilis, and toxoplasmosis
Chronic health conditions such as high blood pressure, diabetes, kidney disease, thyroid disease, anemia, or clotting disorders
Smoking, alcohol use, or illicit drug use during pregnancy
Congenital or chromosome differences in the baby

Sometimes a baby is just naturally on the smaller side, especially if a parent is smaller too. That’s not the same thing as growth restriction, and telling the two apart is exactly why monitoring matters.

Small But Healthy vs. Growth Restricted: How They Compare

Constitutionally small baby — Growing steadily on their own curve, normal blood flow checks, normal amniotic fluid, active movement. Often runs in families.
Growth-restricted baby — Growth that’s slowing or has stalled compared with earlier scans, possible changes in blood flow or fluid level, sometimes reduced movement. Needs closer follow-up.

Your care team uses more than one measurement over time — not a single scan — to tell these apart, since one small measurement doesn’t confirm restriction on its own.

How Providers Diagnose and Monitor It

A few tools work together here:

Fundal height checks — measuring from the pubic bone to the top of the uterus at routine visits. A smaller-than-expected measurement can prompt a closer look.
Growth ultrasounds — used to estimate the baby’s weight and track it over several visits, since a single scan is less useful than a trend.
Blood flow checks — ultrasound-based studies that look at circulation to and from the placenta.
Fluid level checks — the amount of amniotic fluid around the baby.
Nonstress testing — listening to the baby’s heart rate for about 20 to 30 minutes to check how it responds to movement.
Testing for infection or genetic causes — sometimes recommended if growth restriction is confirmed, to help identify the underlying cause.

Practical next steps for Intrauterine Growth Restriction

Your provider notices a smaller-than-expected measurement or you report reduced movement.
An ultrasound estimates the baby’s size and checks blood flow and fluid level.
If growth restriction is suspected, you’re scheduled for repeat ultrasounds to track the trend over time, plus nonstress testing.
Your care team uses those results, together with your own health history, to decide how often to monitor you and whether any additional testing is needed.
If testing shows the baby is under stress, or growth has stalled, your provider will talk with you about the timing of delivery — weighing the risks of staying pregnant against the risks of an earlier birth.

Delivery timing is individual. It depends on gestational age, how the baby is doing on testing, and any other health conditions involved — there’s no single timeline that applies to everyone, and this decision is made with your care team, not on your own.

Questions Worth Bringing to a Prenatal Visit

What specifically made you look more closely at my baby’s growth?
Is this a single measurement or a trend across visits?
How often will I be monitored from here, and what will that involve?
Are there causes we should test for?
What symptoms should send me in right away instead of waiting for my next appointment?
How might this affect decisions about when and how I deliver?

Where current knowledge about Intrauterine Growth Restriction stops

Some situations call for more frequent or more specialized monitoring: multiple pregnancies (twins or more), a prior pregnancy affected by growth restriction, chronic conditions like high blood pressure or diabetes, and pregnancies where preeclampsia has developed. If any of these apply to you, ask your provider how your monitoring plan may differ from a lower-risk pregnancy.

This page is a general overview and doesn’t replace an individualized care plan. It doesn’t cover every possible cause, every testing protocol, or specific delivery timelines, since these depend on your own diagnosis, gestational age, and the judgment of your obstetric team. If your baby has been diagnosed with growth restriction, your provider’s specific recommendations for your situation take priority over anything general written here.

Questions readers ask about Intrauterine Growth Restriction

Does a small ultrasound measurement always mean something is wrong?

No. A single measurement below average can also just mean a smaller baby. Providers usually look at growth over more than one visit, along with blood flow and fluid checks, before diagnosing growth restriction.

Will I need a C-section if my baby has growth restriction?

Not necessarily. Some babies with growth restriction are delivered vaginally; others need a C-section, often because they show signs of stress during labor. Your provider will base this decision on how your baby is doing, not on the diagnosis alone.

Can growth restriction be treated or reversed during pregnancy?

There’s no treatment that reliably reverses growth restriction once it’s diagnosed. Management instead focuses on close monitoring and choosing the safest timing for delivery. Ask your provider what monitoring plan applies to your specific situation.

What happens after birth if my baby was growth restricted?

Outlook after delivery depends on the cause and how severe the restriction was. Some babies catch up in growth; others need extra follow-up care. Your baby’s pediatric team is the right source for what to expect in your case.

Educational Disclaimer

This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. It does not diagnose fetal growth restriction, recommend a specific monitoring schedule, or set a delivery timeline for any individual. Always consult a qualified health care provider about your specific pregnancy and any concerns about your baby’s growth or movement.