Thyroid imbalance has now been found to be affecting even newborn babies.

A study by the neonatology department of Post Graduate Institute of Child Health (PGICH), Noida, conducted on 200 babies who were either preterm or born at nine months but were very sick, has been accepted for publication in the Archives of Endocrinology and Metabolism' journal. The babies were so sick that they had to be admitted to the neonatal ICU (NICU).

According to the study, about 10 per cent of the sample neonates had a deficiency of thyroid hormone. This imbalance and deficiency, experts said, adversely impact the ultimate outcome of the disease for which the babies were admitted to the NICU. It can also increase the severity of illness.

Furthermore, the study found that some children had a congenital deficiency of the thyroid which could put them at risk of developing mental retardation, if not put on thyroid hormone replacement therapy immediately.

Dr Ruchi Rai, head of PGICH's neonatology department, said: "Of the 200 babies, 100 were premature births and the remaining 100 were born on full term but were extremely ill. These babies were admitted to our NICU within seven days of birth. As a routine at PGICH, we conduct a thyroid screening test for all admitted babies on the third or fourth day of life.

We found that about 10 per cent had thyroid deficiency. These babies were at the risk of developing more severe disease, had more chances of being put on ventilator support or developing mental retardation."

Rai emphasised that while a simple blood test on the third or fourth day of birth could pick up thyroid deficiency due to illness contracted after birth, in preterm or sick babies, it might not be enough to diagnose congenital thyroid deficiency. "A repeat test in the third week of life is necessary. All preterm and sick babies must be evaluated," the doctor said.