You doctor or midwife my recommend you have a 3rd trimester ultrasound, this ultrasound can be performed anytime that suits your referring doctor, usually after 23 weeks.
There could be a number of reasons to have a third trimester ultrasound, this may be due to:
- Your baby measuring small for your dates
- Your baby measuring bigger for your dates
- Your baby might be in a breech presentation
- You may have been diagnosed with gestational diabetes or have high blood pressure
- You may have been identified as high risk for Pre-eclampsia in your earlier scans.
- If you are carrying twins or triplets.
It is also important to have an ultrasound if you notice a change in your baby movements or you experience bleeding.
The 3rd trimester ultrasound will:
- Check your baby’s growth
- Assess placental position
- Review findings from a prior ultrasound
- Assess your cervical length
We can estimate baby’s weight from the ultrasound measurements, but variation can be plus or minus 400g
If your baby is optimally positioned, with a pocket of amniotic fluid in front of its face, true-to-life 3D/4D images can be obtained. We find that often visibility can be limited due to the baby being much larger, relative to the decreasing amount of surrounding amniotic fluid, this makes imaging more challenging for our clinicians.