Growth Scan (Third Trimester Ultrasound)
Ultrasound measuring baby's size and growth to ensure appropriate development in late pregnancy.
📅 When Performed
Third trimester (28+ weeks), frequency varies
⏱️ Results Timeline
Immediate preliminary results, official report within 1-2 days
Overview
Growth scans are ultrasounds performed in the third trimester to measure your baby's size and ensure they're growing appropriately. The technician measures baby's head, abdomen, and thigh bone to estimate weight and percentile.
Not all women receive routine growth scans, but they're common for high-risk pregnancies, suspected growth problems, gestational diabetes, or when the fundal height measurement is concerning.
These scans help identify babies who are too small (growth restriction) or too large (macrosomia), both of which can affect delivery planning and need monitoring.
🎯 Purpose of Test
- •Monitor baby's growth and size
- •Estimate fetal weight
- •Detect growth restriction (baby too small)
- •Detect macrosomia (baby too large)
- •Check amniotic fluid levels
- •Assess placental function indirectly
🔬 How It's Performed
- 1.Standard abdominal ultrasound
- 2.Measures head circumference, abdominal circumference, femur length
- 3.Computer calculates estimated fetal weight
- 4.Compares measurements to growth charts
- 5.Determines percentile
- 6.Checks amniotic fluid volume
- 7.Takes 15-30 minutes
👀 What to Expect
- →Similar to anatomy scan
- →Can see baby's features clearly
- →May see baby practicing breathing, moving
- →Photos provided
- →Estimated weight calculated (within 10-15% accuracy)
- →Results discussed immediately
- →Follow-up scans if concerns
✓ Normal Results
Baby growing along consistent percentile (10th-90th percentile), normal fluid levels
⚠️ Abnormal Results
- •Growth restriction (below 10th percentile)
- •Macrosomia (above 90th percentile, estimated weight over 9 lbs)
- •Slowing growth velocity
- •Low or high amniotic fluid
- •May need more frequent monitoring
- •Possible early delivery if severe restriction
- •Consider induction if baby very large
⚠️ Risks & Considerations
- •No risks - ultrasound is safe
- •Anxiety from measurements
- •Weight estimates can be inaccurate (10-15% margin of error)
- •May lead to unnecessary intervention based on estimates
📝 How to Prepare
- →No special preparation
- →Don't need full bladder in third trimester
- →Bring support person
- →Discuss concerns with provider