What is fetal growth restriction?

Fetal growth restriction (FGR), also called intrauterine growth restriction (IUGR), happens when a baby does not achieve its expected growth potential. It affects roughly 3 to 10% of pregnancies. The most common underlying cause is the placenta not delivering enough oxygen and nutrients to the baby.

How is FGR detected?

FGR is identified through serial growth scans — measuring the baby's head, abdomen, and limb length at intervals, usually every 2 to 3 weeks, and plotting this against expected growth curves. A single small measurement isn't necessarily a concern; the pattern of growth over time is what matters most.

Why does the cause matter?

Distinguishing a baby who is genuinely growth-restricted from one who is constitutionally small (simply a smaller, healthy baby, often following family patterns) is one of the central skills in fetal medicine. This is done by combining growth measurements with Doppler studies of the umbilical artery, which assess how well the placenta is functioning.

How is FGR managed?

  • More frequent growth scans to track the trend over time
  • Doppler studies of the umbilical artery and other vessels to check placental function
  • In more significant cases, additional monitoring such as a biophysical profile
  • Timing delivery appropriately — sometimes earlier than the due date — based on how the baby and placenta are coping
When it needs urgent attention Severely reduced or reversed blood flow on Doppler studies is a sign that needs urgent review, as it may indicate the baby needs to be delivered promptly for its own safety. Dr. Chandak will flag this immediately if it's ever seen.

Frequently asked questions

No. Some babies are simply constitutionally small and completely healthy. Doppler studies and growth trends over time help distinguish this from true growth restriction.

Typically every 2 to 3 weeks, to track the growth pattern and combine it with Doppler assessment.

Not always, but in more significant cases, delivery timing is planned around what's safest for the baby based on growth and Doppler findings.