Obstetric Ultrasonography (Pregnancy Ultrasound)

Obstetric Ultrasonography General Questions

What is an obstetric or pregnancy ultrasound?

Obstetric or pregnancy ultrasounds can be used for many different reasons during pregnancy. They help monitor normal baby development and screen for potential problems. During a pregnancy ultrasound, our sonographers can check for the sex of a baby if requested and produce keepsake images for the parents.

First-Trimester Obstetric Ultrasound

During the first trimester (1–12 weeks), patients may be referred for an ultrasound to confirm pregnancy, check for multiple pregnancies, assess gestational age and estimate the due date. Patients may also be referred for many reasons, including the following:

threatened miscarriage
recurrent miscarriages
pelvic pain or mass
hyperemesis
previous ectopic pregnancy.

Patient Guide

How to prepare for your first-trimester pregnancy ultrasound

Please arrive with a full bladder at your scheduled appointment time.
Empty your bladder 90 minutes before and finish one litre of water within the next 30 minutes. Hold for the one hour leading up to your examination.
All our practice locations have toilets to empty your bladder after your examination.
For more information, we recommend reading our blog, Early Weeks of Pregnancy: What Ultrasound Should Show.

Second-Trimester Obstetric Ultrasound

During the second trimester (12–24 weeks), a pregnancy ultrasound can help monitor a baby’s growth and position and check for the sex of the baby. Referrers may order a routine Foetal Morphology Study between 18–22 weeks to check the baby for congenital disabilities and examine different areas in and around the baby, such as the head, brain, heart, placenta, umbilical cord and amniotic fluid.

Patient Guide

How to prepare for your second-trimester pregnancy ultrasound

Please arrive with a full bladder at your scheduled appointment time.
Empty your bladder 90 minutes before and finish 500mls of water within the next 30 minutes. Hold for the one hour leading up to your examination.
All our practice locations have toilets to empty your bladder after your examination.
Please bring any previous imagery for this pregnancy.
For more information, we recommend reading our blog, Pregnancy Ultrasound: Foetal Morphology.

Third Trimester Obstetric Ultrasound

During the third trimester (24–40 weeks or birth), a pregnancy ultrasound can evaluate the baby’s growth and amniotic fluid volumes. Patients with high-risk pregnancies may be referred multiple times during the third trimester.

Patient Guide

How to prepare for your third-trimester pregnancy ultrasound

Please arrive with a full bladder at your scheduled appointment time.
Empty your bladder 90 minutes before and finish 500mls of water within the next 30 minutes. Hold for the one hour leading up to your examination.
All our practice locations have toilets to empty your bladder after your examination.
Please bring any previous imagery for this pregnancy.
For more information, we recommend reading our blog, Pregnancy Ultrasound: Third Trimester Scans.

Nuchal Translucency (NT) Scan

What is a nuchal translucency (NT) scan?

A nuchal translucency scan is an ultrasound scan performed with a blood test to screen pregnant women for chromosomally abnormal babies.

The test suggests which pregnancies are at higher risk of abnormality and may need further investigation. A normal result does not guarantee a normal baby.

An abnormal result does not mean that the baby is abnormal but suggests that the baby should be further investigated.

The ultrasound scan for nuchal translucency (NT) is performed between 11 weeks, three days, and 13 weeks, six days of pregnancy. It is painless and carries no risk to the pregnancy.

For more information, we recommend reading our blog, Pregnancy Ultrasound: Nuchal Translucency Assessment.