The Dating Scan

Most women have an ultrasound scan performed early in the 1st trimester, usually between 7-10 weeks. For very early scans, performed before 8 weeks, it may be necessary to perform a trans-vaginal ultrasound, which is perfectly safe for your baby. After 8 weeks, the normal abdominal scan is usually sufficient.

Because the 1st trimester is a very accurate time to assign a pregnancy “due date”, the 1st trimester ultrasound is often called a dating scan. However, an early pregnancy ultrasound is far more helpful than simply confirming a woman’s due date. Benefits of a 1st trimester scan include:

  • To confirm the pregnancy due date by measuring the fetal “crown-rump length”
  • To check fetal viability and exclude ectopic pregnancy in women with pain or bleeding
  • To detect a multiple pregnancy (twins, triplets) and accurately assign chorionicity
  • Part of a 1st trimester screening package for chromosomal disorders (if 11-14 weeks)
  • To accurately determine placental location in women considering CVS testing
  • To perform an early fetal anatomy survey in women with a previously affected baby

Other Specialist Ultrasound Lists

  • Mater Hospital
  • North Shore Private Hospital
  • The University Of Sydney
  • Royal College Of Obstetricians and Gynaecologists