What is a Growth Scan?
A Growth Scan is an ultrasound examination performed in the third trimester (usually between 28 and 36 weeks) to assess fetal growth, amniotic fluid volume, and placental function. It helps ensure your baby is growing appropriately for gestational age.
What is Doppler Evaluation?
Doppler Evaluation uses ultrasound to measure blood flow in specific fetal and placental vessels, including the umbilical artery, middle cerebral artery, and uterine arteries. It assesses fetal well-being and placental blood flow.
Why are these done?
- Monitor fetal growth trajectory and detect growth restriction or macrosomia
- Evaluate amniotic fluid volume (oligohydramnios or polyhydramnios)
- Assess placental function and blood flow to detect insufficiency
- Identify compromised fetuses at risk of hypoxia or poor outcomes
When should I get it?
Growth scan and Doppler studies are usually recommended between 28 and 36 weeks of pregnancy. Timing may vary based on clinical indications, such as high-risk conditions like hypertension or diabetes.
How is the scan performed?
- You lie comfortably on an examination table with your abdomen exposed
- A gel is applied, and a transducer is moved over your abdomen to measure fetal biometry (head circumference, abdominal circumference, femur length, and estimated fetal weight)
- Doppler ultrasound is used to sample blood flow waveforms in the umbilical artery, middle cerebral artery, and uterine arteries
What does it show?
- Fetal biometric measurements and estimated fetal weight
- Amniotic fluid index (AFI)
- Umbilical artery Doppler: resistance index and pulsatility index
- Middle cerebral artery Doppler: peak systolic velocity and brain-sparing effect
- Uterine artery Doppler: assessment of uteroplacental blood flow
Benefits and Limitations
Benefits:
- Non-invasive evaluation of fetal growth and well-being
- Early detection of growth abnormalities or fetal compromise
Limitations:
- Dependent on operator skill and fetal position
- May not detect all causes of fetal distress
- Results should be interpreted in the clinical context
Frequently Asked Questions (FAQs)
Is the scan safe for my baby?
Yes. Ultrasound and Doppler use sound waves and have no known risks.
Do I need any special preparation?
No special preparation is required; wear loose clothing for comfort.
How long will the scan take?
Approximately 20–30 minutes.
When will I get the results?
Preliminary findings are discussed immediately; a detailed report follows within 1–2 days.
What if an abnormal result is found?
Your doctor will discuss implications and may recommend closer monitoring or early delivery.