Anatomical Survey Scan

This scan is also known as a detailed anatomy scan. The purpose of this scan is to check your baby is normal. Most babies are healthy, but unfortunately some have problems that cannot be predicted by a family history, or the health of the mother. Some of these problems can be serious.

Each part of the baby’s body is examined. We check the development of the following organs or movements on the anatomy scan: head, brain, face, spine, arms, hands, fingers, heart, lungs, bowels, kidneys, bladder, legs, feet, the fluid around the baby, the umbilical cord and position of the placenta. If any abnormalities are detected then we will discuss the significance of the findings.

The majority of serious congenital malformations can be detected by the 20 week scan. So, if the baby appears normal on a scan there is only a small chance that your baby will have a problem. This small chance is because some problems may not be present at 20 weeks but develop later in the pregnancy e.g. diaphragmatic hernias where there is a small hole in the muscle that separates the chest from the tummy (abdomen).

The scan is performed by a specialist sonographer or doctor and the whole examination is recorded. The scan is performed through the tummy wall. Occasionally we may need to perform the scan through the vagina if the baby’s head is low in your tummy in order to check the developing brain.

We have access to a full counselling service for you should any problems be detected and we will send a copy of our report to your hospital, doctor or midwife to ensure good communication between all parties. This is because if we identify some problems on the scan such as a low placenta, you will need a repeat scan again later in the pregnancy to check that it has moved out away from the neck of the womb.

It is possible to determine the sex of the baby on scanning at 20 weeks but we will only tell you if you (and those with you in the scanning room) wish to know this information. If the scan does indicate the sex of the baby then this is right in 95% of cases.

We have included a list of some of the problems that can be detected by this type of ultrasound scan, along with likelihood of detection. (This comes from the RCOG website)

Problem Cause % Seen
Spina bifida Open spinal cord 90%
Anencephaly Absence of the top of the head 99%
Hydrocephalus Excess fluid within the brain* 60%
Major congenital heart problems 25%
Diaphragmatic hernia A defect in the muscle which separates the chest and abdomen 60%
Exomphalos/gastroschisis Defects of the abdominal wall 90%
Major kidney problems Missing or abnormal kidneys 85%
Major limb abnormalities Missing bones or very short limbs 90%
Cerebral palsy Spasticity Never seen
Autism Never seen
Down syndrome May be associated with heart and bowel problems About 40%

* Many cases present late in pregnancy or even after birth

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The anxieties we had with our IVF pregnancy were allayed with the extra scans at Thornbury hospital with Tom Farrell. Helen (Sheffield)