This ultrasound examination (sometimes referred to as an anomaly scan) provides a detailed scan of your developing baby and is recommended at 18- 20 weeks gestation and is considered to be routine practice for all pregnant women in Australia.
What is the purpose of the scan?
At this stage the sonographer and doctor are able to look at the baby’s anatomy (this involves a detailed examination of the baby’s head/brain, face, heart, stomach, kidneys, bladder, spine and limbs) They can also check the position of the placenta in relation to your cervix, the length of the cervix and fluid around your baby.
Why is this scan carried out at 18-20 weeks?
This is thought to be the optimal time to visualise the baby’s anatomy, allowing accurate assessment of the internal organs and limbs. The timing of the scan also allows further testing should an abnormality be found.
What abnormalities can be detected?
Despite advanced technology and the very experienced medical professionals at our practice ultrasound does not detect all abnormalities a baby can have. There are some abnormalities that are only evident later in the pregnancy such as some cardiac defects and bowel abnormalities There are conditions such as cerebral palsy and chromosomal abnormalities that cannot be detected at all. This scan provides reassurance for you and your doctor however dos not guarantee a normal baby or that you will have no pregnancy complications.
What will I be able to see on the scan?
All our ultrasound rooms have a second screen mounted on the wall so you can watch your baby whilst the scan is being performed. The sonographer will point out your baby’s heartbeat and various parts of its body such as its hands and feet and face. The bones will appear white and the soft tissue grey and the fluid surrounding the baby will appear black.
What if there is a problem on the scan?
Approximately 95 % of babies will have a normal ultrasound scan. If there is a problem with your scan you will be informed of this at the time of your scan by a doctor and informed of what the next step will be. Sometimes a repeat scan is required at our practice or in a tertiary referral centre. These results will also be discussed with your referring doctor/midwife. In most cases of repeat scanning no serious abnormality is present.
Do I need a full bladder?
Fluid in your bladder provides a “window” to get better images on your scan. It also helps push the uterus (womb) up from your pelvis and bowel out of the way to better visualise your baby, uterus and cervix. We suggest you empty your bladder an hour before your appointment and drink ¾ of a litre of water and then try not to empty your bladder until after your appointment (your bladder does not need to be so full that it is painful)
Is ultrasound safe for my baby?
Yes ultrasound is safe. Ultrasound scans have been used for over 50 years. They use sound waves and not ionizing radiation like that used in x-rays and CAT scans. Long term studies have shown that there is no adverse effect on the baby from an ultrasound scan performed before birth. Follow-up has shown normal growth and development, normal eyesight and hearing and a normal range of school performance.
Can I find out the sex of my baby?
Please let us know at the beginning of the examination if you would like to know the gender of your baby (also if you do not want to know please let us know) It must be remembered that ultrasound is not 100% in determining the sex of your baby. Sometimes it is not possible to determine the sex due to the position of the baby.
Establishing the sex of your baby is an exciting time for parents, however please remember that the purpose of this scan is to ensure your baby is developing normally and that there are no signs of structural abnormalities.
Will I need any more scans after this?
Usually everything can be assessed on one scan, however in 5-10% cases another scan later that day or on another day may need to be performed when the baby is in another position or when the baby is bigger.
Some women may be required to return for a scan in the third trimester to check the growth of the baby, reassess the position of the placenta or review findings from the morphology scan. Your doctor or midwife will refer you for this ultrasound.
If you have any further questions do not hesitate to call us on 9399 5505 or ask the sonographer on the day of the scan.