Details Scan During Pregnancy – Everything You Need To Know

When can detailed scan be performed?

18-23 weeks of pregnancy is an ideal time to perform the detail scan. This is because the baby’s parts are not crowded, liquor is adequate and most of the fetal part can easily be seen. Earlier scan before 16 weeks is possible with higher resolution ultrasound machines in patients with higher risk of fetal abnormality.

What is done during detailed scan?

During detail scanning, the following structures of the baby will be identified and examined in detail

Head – shape and structures, ensure no excessive fluid in the brain and normal major brain structures
Face- facial profile and to check for any cleft lip/cleft palate
Neck –to ensure no swelling in the front and back
Heart – to ensure normal anatomy and major vessels
Lungs- to ensure no abnormal growth
Diaphragm –to ensure no major defects
Abdomen -stomach, kidneys , intestine, liver , bladder
Genitalia – yes, most pregnant women would like to know
Spine- both longitudinal (length) and transverse (cross section) to make sure that there are no spinal defect.
Limbs -upper and lower limbs to look for extra digits and ensure correct angulation of feet
Cord Insertion and vessels – to ensure no umbilical cyst. 2 arteries and 1 vein
Amniotic fluid
The growth of the baby using bi-parietal diameter, abdominal circumference and femur length.

The table below shows the common abnormalities that can be detected and the chances of being seen in detail scan.

About 20% of all abnormalities will not be seen in the fetal anomaly scan because these abnormalities are difficult to detect or they appear at the later part of your pregnancy. So, there is a small chance that baby may have abnormalities at birth which are not detected during fetal anomaly scan.

Pictures of abnormal babies: