Third Trimester Scan

This is ultrasound after 28 weeks, commonly much later.
It may also be referred to as a growth scan or late Pregnancy Ultrasound.

Late Pregnancy Ultrasound

Some examples of reasons to have a third trimester ultrasound are:


  • The fetus, or the mother’s abdomen, feels too big or small for the stage of pregnancy.
  • The mother has a medical condition that can affect fetal growth and well-being, such as high blood pressure or gestational diabetes.
  • The placenta was low-lying on the midtrimester ultrasound.
  • The position of the fetus could be unusual e.g. breech.
  • Abnormal symptoms such as pain or bleeding.
  • Movements decrease.
  • A fetal abnormality was noted at an earlier ultrasound and requires a follow-up.
third trimester scan
third trimester scan

Third trimester ultrasound (late ultrasound) includes:

  • Fetal position.
  • Fetal size: an estimated fetal weight is calculated from measuring the fetal head, abdomen and femur.  The weight ‘estimate’ is truly that, with one standard deviation being 15% either side of the true weight.
  • Some assessment of fetal anatomy: bearing in mind, late pregnancy limits the views and the check will not generally be a universal check, like the 19-week ultrasound.
  • Placental position and maturity.
  • Amniotic fluid volume.
  • The Doppler blood flow in the umbilical cord and the brain. This gives an idea of the placental function and reserve.
  • Fetal movements.
  • Other factors that are requested by the referring doctor.

QDOS Ultrasound is located in West Leederville, Perth. Call 08 9481 4008 to make a booking.

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Contact QDOS Ultrasound

12 Connolly St, West Leederville
PERTH - Western Australia 6007

Phone 08 9481 4008
Fax 08 9481 4080

Monday - Friday
8:00 am - 4:45 pm
(strictly by appointment only)

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