Anomaly scan, also known as fetal anomaly scan or level 2 anomaly scan, or targeted imaging for fetal anomalies, is an ultrasound scan that is done in the second trimester of pregnancy. It is commonly done between 18 to 23 weeks of pregnancy to evaluate the development and growth of the baby. The formation of the baby’s organs is complete by the time pregnancy reaches the second trimester. During this period, all organs are easily visualized in the anomaly scan of fetus.
Why do an anomaly scan?
It is essential to do an anomaly scan of your baby before it is born, to identify any birth defects that may be present and take appropriate measures if required.
The anomaly scan can detect major defects like the following:
Apart from identifying physical defects in the developing baby, an anomaly scan report also remarks on following aspects:
2. Gender of the baby.
3. Umbilical Cord
4. Amniotic Fluid
5. EDD (Expected Date of Delivery)
Anomaly scan format
Normally, the anomaly scan has predefined guidelines set for the measurement of certain factors in the growing baby. The baby’s measurements should correspond to the age set in the guidelines. The factors include:
Ultrasound soft markers
There are certain variants or small deviations in normal findings of the 2 trimester anomaly scan. When present singly or not to a very significant degree, these findings do not point to any abnormality in the unborn baby. These are called as ultrasound soft markers.
Single or very slight deviations are very commonly seen in a normal baby and are not considered abnormal.
When more than one or two prominent soft markers are seen on the scan, it increases the doubt of chromosomal defects.
Ultrasound soft markers taken into account while diagnosing a genetic abnormality include:
Under normal conditions, ultrasound soft markers are usually present temporarily and disappear in the subsequent anomaly scan at 33 weeks.
Anomaly scan of a genetic defect, like Down’s syndrome shows the presence of nuchal fold, not well formed nasal bones, short hands and legs, curved little finger, renal pelvic dilatation, etc.
Disclaimer: The information in the article is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your doctor.