It is a mid-trimester ultrasound done for the detailed evaluation of the baby. It serves as a baseline against which later scans can be compared for the growth.
Anomaly scan is also referred by the names of Level II scan, target scan or TIFFA scan.
The purpose of the scan is to determine the cardiac activity, number of fetuses and chorionicity (type) if multiple pregnancy and correctly date the pregnancy.
The weight of the baby, fluid around the baby and the assessment of placenta is also done. This serves as a baseline for the later scans to determine the well-being of the baby.
It involves detailed evaluation of the head and spine, face and neck, heart and its connections, thorax, abdomen, kidneys and urinary bladder, arms and hands and legs and feet.
We perform the anomaly scan in accordance with the guidelines and the protocol laid down by ISUOG (International Society of Ultrasound in Obstetrics and Gynaecology) and FMF (Fetal Medicine Foundation, UK) guidelines.
The 3D/4D scan has no role. But we do 3D and 4D in all our anomaly scans, as it adds more details to our assessment.
An anomaly scan is usually performed between 18 to 24 weeks. In India, it is performed between 18 to 20 weeks as the legal limit for termination by Medical Termination of Pregnancy Act is uptil 20 weeks.
All pregnant female should be offered a detailed mid trimester scan to assess the fetal structural abnormalities and pregnancy complications.
Individuals who routinely perform obstetric scans should have specialized training for the practice of diagnostic ultrasonography in pregnant women.
Prenatal ultrasonography appears to be safe for clinical practice. To date, there has been no independently confirmed study to suggest otherwise.