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.