- Also: FGR
- Also: intrauterine growth restriction
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.

