According to a study conducted by pathology specialist Metropolis Healthcare Ltd, women who get married late have delayed first pregnancy have a greater risk of babies being born with Down’s syndrome.
The stud carried out about 40,000 prenatal screenings that detected the syndrome in the foetus. It was revealed that a woman who 40 years old at the time of conceiving her first child has a 16 times greater risk of giving birth to a baby suffering from Down’s syndrome, compared to a woman who conceives at the age of 25. Deepak Sanghavi, head of the department of clinical chemistry and accession at Metropolis Healthcare Ltd, says ‘With the increase in the maternal age, the likelihood of having a child affected with Down’s syndrome increases considerably.’
Out of the 2,996 mothers aged between 35 and 40 years, 21.89 percent tested positive for Down’s syndrome during pregnancy, while 7.78 percent of the 9,965 mothers aged between 31 and 35 years had the risk, the survey said.
What is Down’s syndrome?
Down’s syndrome, one of the most common genetic disorders in children, occurs when there are three instead of the two usual copies of the chromosome 21 due to an error in the process of cell division. As a result of this ‘trisomy’, people with the syndrome have extra copies of more than 300 genes. The syndrome is associated with intellectual disabilities, a delay in cognitive ability and physical growth, distinctive facial features like flat face, slanted eyes, short necks, etc., and sometimes heart problems and other health effects. Researchers have discovered that the extra chromosome inherited in the syndrome impairs learning and memory because it leads to low levels of SNX27 protein in the brain. Children born with genetic birth defects like Down’s syndrome are at an increased risk of developing childhood cancer, says a study.
Down’s syndrome is usually identified at birth. The nuchal translucency scan or the NT scan conducted between the 11 and 13 weeks of pregnancy can help assess the foetal risk of developing the syndrome. Amniocentesis and chorionic Villus Sampling coupled with the results of an NT scan gives an accurate estimation. A simple non-invasive blood test called non-invasive analysis for chromosomal examination (NACE) which has a near-zero risk to foetus and has no risk of abortion can now detect the syndrome in a pregnant female within three months of pregnancy.
How can Down syndrome be detected?
Since the condition cannot be cured it is necessary to detect the same before the child is born, right during pregnancy. Several prenatal tests and screening tests are done to detect the condition in the unborn child.
The screening tests include:
Nuchal translucency scan or NT scan: This is done between 11 and 14 weeks of pregnancy, using an ultrasound to measure the fluid present in the folds of tissue behind a developing baby’s neck. Usually babies with a genetic defect like Down syndrome tend to accumulate fluid behind their neck. The mother’s age along with the NT scan results and a blood test gives an idea about the probability of a baby being born with the condition. Know why an NT scan is important during pregnancy?
The triple marker or quadruple marker test: Done usually between the 15 and 18 week of pregnancy, this is a blood test done to check certain markers in the blood that can point to any chromosomal abnormality.Read more about Down syndrome – causes, symptoms, diagnosis, prevention and care.