Detecting baby’s disease before birth

Mr Alim (name disguised to protect identity) has a child of 7 years old who is diagnosed with Haemoglobin E Beta Thalassaemia Major. It is a genetic disease where there is destruction of red blood cell. Mr Alim came to me periodically for advice and for blood transfusion for the child.
He became deeply concerned when his wife became pregnant again. He asked me if there was any way to predict the same genetic disease in his upcoming baby. I advised them to screen with a method called Chorionic villus sampling and the results showed that upcoming baby had the same disease like its sibling. Then parents were counselled and ultimately they decided to abort the baby with therapeutic abortion.
If any parents already have a child with congenital problems or history of genetic diseases, diagnosis before birth (prenatal diagnosis) is very helpful.
There are three purposes of prenatal diagnosis: (1) to enable timely medical or surgical treatment of a condition before or after birth, (2) to give the parents the chance to abort a fetus (baby in the womb) with the diagnosed condition, and (3) to give parents the chance to "prepare" psychologically, socially, financially and medically for a baby with a health problem or disability, or for the likelihood of a stillbirth.
In Bangladesh, we are still lagging behind from many developed countries regarding prenatal screening tests. Many invasive tests like Chorionic villus sampling is not available in Bangladesh but sample can be sent abroad for diagnosis. Prenatal diagnosis can be done by a number of tests including blood test, ultrasonograhy, tissue sample from baby and the bag containing baby.
Invasive tests like amniocentesis or chorionic villus sampling is indicated in the following circumstances:
• Maternal age over 35 years
• Previous child with chromosomal abnormalities
• A history of any genetic disorder like Down Syndrome diagnosed by biochemical techniques or by DNA analysis
• A request by the parents for fetal sex determination because of history of an X-linked disorder that is not otherwise diagnosable
• Maternal blood testing indicating increased risk for chromosomal abnormalities
• As part of the work up of fetal anomalies found by ultrasonography

The writer is a Professor of Paediatrics, working at Community Based Medical College, Mymensingh. E-mail: mmukkhan@gmail.com