Fetal Anomaly Scan

The fetal anomaly scan is a detailed ultrasound scan performed to take a closer look at the womb and the baby between weeks 18-21 of pregnancy.

Purpose of the fetal scan

The aim of this scan is to detect abnormalities in the unborn baby.

Is the fetal scan mandatory?

All pregnant women are informed about the scan, its purpose, and what it can and cannot detect. Thereafter the decision is entirely hers. The woman’s consent is necessary for the scan to be performed.

Type of scan

There is technology available to produce both 2D and 3D images that may be black and white, or in colour. Different women’s hospitals offer different facilities. Make sure to pick a women’s hospital that fits what you want.

How is a fetal scan performed?

The sonographer applies a gel on the belly and moves a transducer over it to obtain images of the baby.

Duration of the scan

The fetal scan usually takes about half an hour.

Areas of focus in the scan

The sonographer will examine all your baby’s organs and take measurements.

Baby’s body partChecked for
Shape and size of head and brainBrain problems
FaceCleft lip
SpineBone alignment
Abdominal wallWhether it covers all the internal organs at the front
HeartEqual size of atria and ventricles

Proper functioning of valves

KidneysProper functioning of the bladder
Hands and feetDevelopment of muscles and fingers and toes
PlacentaPosition
Amniotic fluidEnough quantity for baby’s free movement
Circumference of head and abdomen; femur lengthMatch with standards of normal development

Which abnormalities can be seen on the scan?

Sonographers have a list of conditions to look out for.

Here’s a list, along with the likelihood of detection:

  • Absence of the top of the head (anencephaly): 98 per cent
  • Cleft lip: 75 per cent
  • Abdominal defects
  • Missing or very short limbs: 60 per cent
  • Spinal defects: 90 per cent
  • Major kidney problems: 84 per cent
  • Chromosomal abnormalities: 95 per cent
  • Major heart problems: 50 per cent

Results of the scan

In most cases, babies develop normally, and no anomalies are picked up. In case a problem is suspected, the sonographer gets a second opinion from an experienced colleague or a specialist. It must also be remembered that scans aren’t fool-proof and there are chances the baby may be born with an anomaly that went undetected.

What happens in case a problem is detected

Other tests or scans may be recommended to understand the problem better. In case an anomaly is confirmed, the further course of action depends on its seriousness. Less serious anomalies may get better on their own. In case of serious anomalies, the family is provided with support, information about all the possible courses of action, including the termination of pregnancy, and the time to make a choice. The family’s choice is always respected.

Finding out about problems before birth helps plan post-birth treatment. This is especially beneficial in cases where surgery immediately after birth is likely to enhance the baby’s chance of recovery or survival.