Prenatal Screening
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Ultrasound
20 – 22 WEEK SCAN/ANATOMY SCAN
(INCLUDING FETAL ECHOCARDIOGRAPHY)
This scan can be done between 20 – 22 weeks gestation. This scan involves a meticulous and systematic review of the fetus’ development from head to toe, including all the organ systems like the brain, face, heart, gastric, kidneys, spine, and extremities. Each organ is evaluated for position, size, relation to other organs and normality for gestational age. Fetal growth and liquor, placental position and risk of preterm labour is also determined. The last mentioned is only done if indicated (i.e., first pregnancy or previous preterm delivery). If you wish, one can also determine or confirm the gender at this stage.
This examination requires patience as the baby would need to turn in a favourable position for us to complete all standard views and fetal echocardiography. If need be, the examination might need to be completed at another time (at no additional cost).
An attempt will be made to include a 3D/4D picture of your baby during the examination, however the screening mostly consists of 2D images and screening for fetal anomalies remain our main priority.
Image quality is dependent on several factors:
- Difficult fetal lie
- Position of the placenta
- Amount of amniotic fluid
- Advanced gestation
- Maternal habitus or abdominal scar tissue – Ultrasound uses sound waves which penetrate the maternal skin. The sound waves are reverted to the ultrasound probe and thus the image viewed depends on the maternal skin density. It can be difficult to visualize every detail well if your BMI is above 30.
Limitation of ultrasound
Ultrasound cannot exclude all chromosomal abnormalities, rare genetic or significant conditions (like cystic fibrosis, cerebral palsy, autism, etc) as not all can be detected during pregnancy or some (like dwarfism, hydrocephalus, bowel obstruction etc.) may only develop later in pregnancy. During the ultrasound examination we work with what your baby is willing to show us, not with its DNA. Therefore a some small risk will always remain.