Dating scans (<12 weeks) are typically performed in the first trimester.
The purpose of the dating scan (<12 week) is to assess:
- Number of foetus
- Position of foetus
- Determine due dates
- Assess maternal structures
In most cases the scan will be performed transabdominally, but there are some situations where a transvaginal (internal) ultrasound may be necessary. Transvaginal ultrasound involves inserting a thin transducer (ultrasound probe slightly thicker than a tampon) into the vagina to get more detailed images as the transducer is closer to the pelvic organs. This improves the accuracy of diagnosis.
Transabdominal and transvaginal ultrasound examinations are safe at all stages of pregnancy.
You can use our Pregnancy Scan Calculator to work out the best time for your scans.
Before your dating scan (<12 weeks)
If possible, please wear comfortable, loose-fitting clothing that allows easy access to the area that is being imaged. Two-piece clothing is ideal (separate upper/lower garments).
Please empty your bladder 2 hours before the examination time. Then slowly drink 600ml of water to fill your bladder and keep it full for your examination.
When you visit Adelaide Women’s Imaging for your dating scan (<12 weeks) you will be greeted by one of our friendly reception staff. A sonographer will then collect you from the waiting room and take you to the ultrasound room. The sonographer will perform an ultrasound of the abdomen (transabdominal ultrasound), assessing the pregnancy.
In early pregnancy (<9 weeks) it is often better seen with a scan performed through the vagina (transvaginal imaging). Transvaginal ultrasound involves inserting a thin transducer (ultrasound probe slightly thicker than a tampon) into the vagina to get more detailed images as the transducer is closer to the pelvic organs. The transducer is lubricated with gel before insertion into the vagina. It is disinfected, and a protective cover is placed over the transducer each time it is used, so there is no risk of infection. This improves the accuracy of dating the pregnancy.
Once the necessary images have been taken, you will then see one of the Adelaide Women’s Imaging Doctors who will discuss the results with you. A detailed report will also be sent to your referring Doctor.
Duration of Scan
Approximately 30 minutes.