Pregnancy Ultrasound

Pregnancy Ultrasound refers to a non-invasive painless examination of a pregnant woman to assess the development and well-being of her pregnancy. It assesses fetal growth, position and anatomy. Pregnancy ultrasound may be used at various stages of the pregnancy to obtain valuable information about the progress of the pregnancy.

Ultrasound can detect many, but not all abnormalities. Demonstrating a fetal abnormality on ultrasound depends on many factors, including fetal age and position at the time of the ultrasound, and the size and type of abnormality.

There is very little preparation required for these exams. You should have some fluid in the bladder, and it is recommended to wear clothing that allows easy access to the entire abdominal region. Medicare provides a rebate for ultrasound during the first and second trimester, and when there is a clinical concern.

First trimester ultrasound is performed in the first three months of a pregnancy.

Your doctor may request this ultrasound for a number of reasons, including to confirm the presence of your baby’s heartbeat, the correct dates of your pregnancy and the location of your pregnancy. The ultrasound may also be requested to determine the number of babies present, checking other pelvic organs, identifying pregnancies at an increased risk of miscarriage or pregnancy loss and investigating possible causes of abdominal pain or vaginal bleeding.

FIRST TRIMESTER SCREENING

A nuchal translucency ultrasound (commonly called a “nuchal scan” or “NT scan”) is an ultrasound performed ideally between 12-13 weeks gestation. It is usually part of a non-invasive risk assessment called combined first trimester screening.

Combined first trimester screening assesses the risk for your baby having certain chromosomal abnormalities (Trisomy 13, 18 and 21). This testing combines the nuchal translucency ultrasound with specific blood tests. Nuchal translucency ultrasound alone can also provide this risk assessment, but it is not as accurate as combined first trimester screening.

Combined first trimester screening is a “screening” test only, and is not 100% accurate.

This test gives us an indication of whether your baby has a high or low risk for chromosomal abnormalities and if further invasive testing is required based on these results.

A second trimester morphology scan is performed in the middle part of the pregnancy, at around 20-22 weeks gestation. Almost all pregnant women have this ultrasound as a routine part of their antenatal (pregnancy) care. This scan is used to check fetal growth and to provide detailed images of your developing baby.

There are many aspects of the pregnancy that the sonographer will assess during this ultrasound to ensure that your baby is developing normally including the baby’s anatomy or structure, measurements of the baby, heart rate and rhythm, number of babies, position of the placenta, amount of amniotic fluid around your baby, as well as the uterus, ovaries and cervix.

A third trimester ultrasound is performed in the last part of the pregnancy, usually after 24 weeks gestation.The third trimester ultrasound is not considered a part of routine antenatal care, and may be requested by your doctor to check the fetal position, placental appearance and site, how much fluid is around the baby, fetal well-being and the baby’s growth compared with previous scans and the expected date of delivery. It may also be used to investigate various symptoms such as pain, contractions, vaginal bleeding or reduced foetal movement, and also for the monitoring of twin/multiple pregnancy.

You will need to bring your referral from a doctor or specialist to the appointment. Medicare or concession card along with any previous imaging not performed at Lake Imaging.

Please empty your bladder 2 hours before your appointment time and then drink 4-5 glasses of water (not coffee or tea). Please finish drinking your water at least one (1) hour before your appointment and hold this fluid until your appointment.

For third trimester ultrasound, you can reduce the amount of water required to 1 glass, 1 hour prior.

Do NOT empty your bladder until after the examination.

Obstetric ultrasounds are generally performed via a transabdominal approach, however transvaginal scans may be required to provide more detailed information.

Transabdominal ultrasound involves scanning through your lower abdomen. The sonographer who will perform your examination will apply a warm layer of gel to your abdomen/pelvis. This allows for good contact between the skin and the ultrasound transducer.

Transvaginal ultrasound is an internal ultrasound and involves insertion of a small ultrasound probe into the vagina. It may need to be performed where there is difficulty visualising specific areas accurately, to assess for a low lying placenta, cervical length or other medical indications.

Transvaginal ultrasound during pregnancy, is safe and will not harm either you or your baby. Your Lake Imaging sonographer will be experienced at performing these ultrasounds during pregnancy.

The transvaginal scan is performed with an empty bladder and patient discomfort is minimal. The small sterilised probe (about the same diameter as a thumb), is covered with a protective cover and lubricated with gel before being inserted a short distance into the vagina.

Your privacy will always be respected during ultrasound examinations, and you will always have a choice about whether the transvaginal ultrasound is performed. Please discuss any concerns you may have about the scan with the sonographer before your scan is performed.

A radiologist will interpret the ultrasound images and provide your referring doctor with a comprehensive report. We recommend that you make a follow up appointment to discuss the results with your referring doctor.

If the results are needed urgently, or you have an appointment immediately after your scan with your referring doctor or health care provider, Lake Imaging will arrange to have your results available immediately.

Ultrasound uses high-frequency sound waves to produce images, there are no known side effects from having a diagnostic ultrasound scan performed for medical imaging purposes.

The sonographer applies techniques to ensure that your scan is a safe procedure. For this reason, your scan should only be performed by an accredited sonographer, or trained medical practitioner, and a scan should only be performed when clinically indicated.