# IUGR — Fetal Growth Restriction

Source: https://www.pregnancypowerhour.com/conditions/iugr
Last updated: 2026-07-15

> Intrauterine Growth Restriction (IUGR), also known as Fetal Growth Restriction (FGR), means your baby's estimated weight is below the 10th percentile for their gestational age.

When your care provider mentions that your baby is measuring smaller than expected, it can bring a wave of questions and concern. This is often described clinically as Intrauterine Growth Restriction (IUGR) or Fetal Growth Restriction (FGR), a condition where your baby's estimated weight is below the 10th percentile for their gestational age.

## What it is

Intrauterine Growth Restriction (IUGR) is diagnosed when your baby's estimated fetal weight falls below the 10th percentile for their gestational age. It's important to understand that this is distinct from a baby who is simply "constitutionally small" – meaning they are healthy but naturally petite. Your care team uses tools like Doppler blood flow studies to help differentiate between true growth restriction and a healthy, small baby, offering a clearer picture of your baby's well-being.

There are several factors that can contribute to IUGR. The most common cause is placental insufficiency, where the placenta isn't providing optimal nourishment to the baby. Other contributing factors can include maternal health conditions like hypertension or vascular disease, as well as lifestyle choices such as smoking and substance use. In some cases, chromosomal abnormalities or infections can also play a role. Understanding these potential causes can help you and your provider develop a tailored plan for monitoring and support.

## What it tends to feel like

Receiving news that your baby is measuring smaller than expected can naturally lead to feelings of anxiety and uncertainty. As a doula, I often hear from parents who feel a heightened sense of vigilance, constantly wondering if everything is okay. It's a time when you might find yourself more attuned to your baby's movements and your own body's signals. This experience can feel isolating, but remember that you are not alone in navigating these emotions. It's a period that calls for clear communication with your care team and leaning on your support system.

## What the evidence says helps

The cornerstone of managing IUGR is careful monitoring. Umbilical artery Doppler studies are a key tool, and evidence suggests their use to guide the timing of delivery can reduce perinatal mortality. Your care team will also use other methods to assess your baby's well-being, such as biophysical profiles (BPP) and non-stress tests (NSTs). These tests provide valuable information about your baby's movements, breathing, and heart rate patterns.

While there's no treatment that can reverse IUGR once it's established, managing modifiable risk factors can make a difference. For instance, if smoking is a factor, smoking cessation is recognized as a highly impactful step, potentially reducing the risk by approximately 50%. The primary clinical decision in cases of IUGR revolves around the optimal timing of delivery, carefully balancing the risks of remaining in utero against the risks of early delivery. This is a collaborative decision between you and your medical team.

## Working with your care team

Navigating an IUGR diagnosis means engaging closely with your care team. They are your best resource for understanding the specifics of your baby's situation and making informed decisions. Don't hesitate to ask questions about the monitoring schedule, the results of tests like the Doppler studies, and what each finding means for your baby. Discussing potential delivery timing and options, much like you might discuss options for managing a [Breech Baby Position](/conditions/breech-presentation) or understanding patterns in [Prodromal Labor](/conditions/prodromal-labor), will be a key part of these conversations.

It's also helpful to be aware that babies born with IUGR may have a higher long-term risk for certain cardiovascular and metabolic conditions. This information isn't meant to cause alarm, but rather to provide context for ongoing care discussions with your pediatrician after birth. Your role is to stay informed, communicate openly, and trust your instincts while working collaboratively with your medical providers to support your baby's health and your own well-being. Remember, your voice and preferences are an important part of this journey.