Prathima Radhakrishnan
Conslutant in Foetal Medicine
MBBS MRCOG (UK)
Diploma in Obstetric Ultrasound (RCOG, UK)
Fellowship in Foetal Medicine (FMF, UK)

Dr. Prathima tells you what problems can be detected with a sonography, when additional check-ups are warranted, and more.

What are the problems that can be detected with a sonography?

On a scan, physical defects in the baby can be detected with much confidence and a high degree of accuracy. However, there are some indications, called 'markers', which are not structural defects in themselves but are kind of indirect clues to a possible underlying genetic or chromosomal disorder. Some of these markers are strongly associated with such chromosomal or genetic disorders whereas some are weakly associated. If any marker is seen on the scan, this will merit further investigation based on what is the marker, whether there are multiple markers, whether this has a strong or a weak association with the disorder, the age of the mother etc.

Are there certain women who require more sonography check-ups than others? Why is this?

If the mother has certain health problems (like high blood pressure, diabetes etc) or if her abdomen is too small or too large for the stage of pregnancy she is in, a scan is performed to assess the growth and well-being of the foetus. If a mother has had any previous children with abnormalities or if there is a family history of a certain abnormality, extra scans are often recommended in the current pregnancy to track every stage of the baby's development. This ensures early diagnosis of any problem, and also provides reassurance to the parents if the baby is growing normally. It really depends on the kind of problem and more importantly, if the scan can detect or give some leading clues to such a problem. Certain women may develop high blood pressure during pregnancy. A scan can also let you know if you are at risk for developing high blood pressure, and remedial measures can be taken at the outset.

What are the risks a sonography poses to the foetus? Is there any radiation in sonography?

There are no known harmful effects associated with the medical use of sonography. Widespread clinical use of diagnostic ultrasound for many years has not revealed any harmful effects at all. Studies in humans have revealed no direct link between the use of diagnostic ultrasound and any adverse outcomes. Yes, it is possible that biological effects may be identified in the future, but current information indicates that the benefits to patients far outweigh the risks, if any, that may be present. The 'low risk-benefit' ratio has been endorsed by AIUM (American Institute of Ultrasound in Medicine) and RCOG (Royal College of Obstetricians and Gynaecologists, UK), two world bodies that set standards in medicine.

No, sonography does not emit 'radiation'. They emit is 'sound waves' of higher frequency than the human ear can hear - hence the term 'ultrasound'.

When do you need a full bladder, and when do you need an empty bladder? Why does it matter?

When a scan is done by the abdominal route some sonologists prefer to have a full bladder to allow better visualisation of the organs behind the bladder like the uterus, an early pregnancy etc. For an 'internal' scan, empty bladder is preferable.

Do you have any questions you would like to ask Dr. Prathima Radhakrishnan? Email her at editor@indiaparenting.com.