15 January 2010
By Umesh Isalkar
If Undiagnosed, It Can Lead To Mental Retardation Within Two Years: Expert
Of every 3,500 births in the city, one new-born suffers from hypothyroidism – low secretion of hormone thyroxin. Experts say that if the disorder remains undiagnosed and untreated, it can lead to severe mental retardation within first two years of birth.
“Incomplete development of thyroid is the most common defect and occurs in one in every 3,500 births. If undiagnosed and untreated, it can invariably lead to mental retardation. Hence, early diagnosis plays a very important role,” said endocrinologist Uday Phadke. If the baby is born with the condition, it is called congenital hypothyroidism, added Phadke. Gynaecologists should, therefore, subject every newborn to screening test, added Phadke.
Elaborating it further, Phadke said, “Replacement therapy with thyroxine tablets is the standard treatment of hypothyroidism. Once medication starts, thyroid blood tests are regularly done to make sure levels are within normal range.” Early diagnosis generally results in a good outcome. Newborns diagnosed and treated in the first month or so generally develop normal intelligence, he added.
“Untreated hypothyroidism can lead to severe mental retardation and growth retardation. Critical development of the nervous system takes place in the first few months after birth. Hence, thyroid hormone (thyroxin) deficiency may cause irreversible damage,” said gyanecologist Sanjay Gupte, president of the Federation of Obstetric and Gynaecological Societies of India (FOGSI).
Symptoms of Hypothyroidism
- Persistence of jaundice
- Dry skin
- Dull Look
“Around 90 per cent cases of congenital hypothyroidism occur due to dysgenesis (incomplete development of thyroid gland or total absence of it). Following which, thyroxin is not produced in adequate amount. This hormone is extremely essential for the development of central nervous system and neuronal architecture,” said geneticist Prakash Gambhir, professor and head, department of genetics, immunology and biochemistry of Maharashtra University of Health Sciences (MUHS)
Elaborating it further, Gambhir said, “Before delivery, a small amount of thyroxine produced by mother cross-over to foetal side. These small amounts are used extremely efficiently by the foetus so that the brain development is taken care of by this maternal thyroxine till the baby takes birth. After birth, the supply of this maternal thyroxine stops so the brain development is hampered and baby stands to lose five IQ points for each week’s delay in initiation of treatment. That’s why every new born should be screened for congenital hypothyroidism.”
In India, the incidence of hypothyroidism is found to be quite high. As per the largest study carried out by a Hyderabad-based Centre for DNA Fingerprinting and Diagnostics and (CDFD), the incidence of hypothyroidism in new borns is found to be one per two thousand births as against one per 3,000 birth seen in developed countries. “This is the preventable cause of mental retardation especially when the treatment is started in new-born stage,” said Gambhir.