Obstetric Examinations

Obstetric ultrasound provides assessment throughout pregnancy, supporting the evaluation of pregnancy development, fetal growth, anatomy and wellbeing.

The type of ultrasound examination performed will depend on the stage of pregnancy and the clinical indication. Examinations may be performed using a transabdominal and/or transvaginal approach where appropriate.

Early Pregnancy Ultrasound

Early pregnancy ultrasound may be performed during the first trimester to assess the location and development of the pregnancy.

Depending on gestational age and the clinical indication, the examination may assist with:

  • Confirming the intrauterine location of the pregnancy.
  • Establishing or confirming gestational age and estimated date of delivery.
  • Assessing fetal cardiac activity when appropriate for gestational age.
  • Determining the number of embryos/fetuses.
  • Evaluating early pregnancy where there is pain, bleeding or other clinical concern.

A transvaginal examination may sometimes provide more detailed assessment in very early pregnancy. When appropriate, this will be explained to you before the examination and performed with your consent.

First-Trimester Assessment

First-trimester ultrasound may include assessment of fetal development, gestational age and early anatomy. Where specifically requested, a nuchal translucency (NT) assessment may also be performed within the appropriate gestational period.

Fetal Anatomy / Anomaly Scan

The detailed fetal anatomy examination is performed during the second trimester to systematically assess the developing foetus.

The examination includes assessment of major fetal anatomical structures, placental location, amniotic fluid and other relevant features of the pregnancy. Fetal measurements are also obtained to assess growth in relation to gestational age.

Fetal Growth & Wellbeing

Ultrasound examinations later in pregnancy may be performed to assess fetal growth and wellbeing.

Depending on the clinical indication, assessment may include:

  • Fetal biometry and estimated fetal weight.
  • Placental location and appearance.
  • Amniotic fluid volume.
  • Fetal movements and cardiac activity.
  • Doppler assessment when clinically indicated or requested.

Preparation for examination:

For transabdominal obstetric ultrasound

  • For early pregnancy examinations, you may be asked to attend with a comfortably full bladder.
  • If bladder preparation is required, specific instructions will be provided when your appointment is made.
  • Later pregnancy examinations generally do not require a full bladder unless specifically advised.
  • For your comfort and ease of examination, two-piece clothing is recommended.

For transvaginal ultrasound

  • You will usually be asked to empty your bladder before the examination.
  • A transvaginal examination will only be performed when appropriate and with your consent.
  • The procedure will be explained before the examination.