The Anomaly Scan at 18-22 weeks

An anomaly scan, also known as detailed morphology scan, intends to take a closer look at the baby and the uterus. 

The Fetal Medicine Specialist will check how the baby is developing plus the position of the placenta. 

Anomaly scan is often called a 20-week scan; however, a patient may have it any time between 18 weeks and 22 weeks. 

Although the main target of the scan is as mentioned above, the gender, however, may be revealed by the Fetal Medicine Specialist if desired by the patient.  By 12 weeks gestation, gender accuracy is 95% while at 16 weeks, it is 99%++.

The whole scan takes about 30 minutes for a single gestation.  The Fetal Medicine Specialist will assess the fetal organs.

Major organs are mostly checked by cross section and measured, these are:

·         

    The shape and structure of the head and brain.

·         The Face - Cleft lip and Palate are checked while focusing on the face.

·         The Spine, its length and in cross section, making sure that all the bones            align, and that the skin covers the spine at the back.

·         The Heart. Normal structure, location, normal rhythm pattern.

·         The Abdominal wall making sure it covers all the internal organs at the              front.

·         The Stomach.

·         The Kidneys, confirming that the baby has 2 kidneys and bladder is visible.

·         Fetal Extremities. Arms, Hands, Fingers, Legs, Feet, Toes

The placenta location and structure, umbilical cord and the amniotic fluid are also checked.

To see how well the baby is growing, the HC (head circumference), AC (abdominal circumference) and FL (femur length-thigh bone) measurements should match up depending on when is the expected delivery date.

Authored by Dr. Afshin PourMirza, MD, PhD

Obstetrics and Gynaecology – Maternal Fetal Medicine

Managing Director of Feto Maternal and GenetYX Center