An ultrasound in third trimester may be performed at any stage after 23 weeks up until delivery.
There are many reasons a third trimester ultrasound may be indicated including:
- A baby measuring larger or smaller than expected
- Uncertain position (e.g., breech)
- Gestational diabetes or high blood pressure
- High risk for pre-eclampsia
- Multiple pregnancy (e.g., twins or triplets)
- Reduced movements
- Small baby in previous pregnancy
During the third trimester ultrasound, the following is examined:
- Fetal size and estimated weight
- Placental position and function through blood flow measurements
- Cervical length (if prior to 28 weeks)
- Volume of amniotic fluid
- Fetal position
- Review of fetal organs
If the baby is optimally positioned, with a pocket of amniotic fluid in front of the face, a 3D image can often be obtained. The quality of these images is extremely dependant on a number of factors, therefore there is no guarantee that a 3D image can be achieved. There is no additional fee charged for a 3D image.
