Study throws light on congenital deafness

CAN YOU HEAR US: A new born being tested for signs of hearing impairment at the Institute of Obstetrics and Gynaecology in Chennai.

CAN YOU HEAR US: A new born being tested for signs of hearing impairment at the Institute of Obstetrics and Gynaecology in Chennai.  

WHO city project data points to incidence of deafness of three per every thousand live births The one-year pilot study involving screening of newborns for hearing impairment is to promote universal hearing screening at all maternal hospitals.

Staff Reporter

CHENNAI: Preliminary data from a WHO-supported study involving screening of newborns in a Government hospital in Chennai points to a deafness incidence of three per every thousand live births.

The pilot "Universal Neonatal Hearing Screening" study launched by KKR ENT Hospital and Research Institute aims to screen 5,000 newborns at the Government-run Institute of Obstetrics and Gynaecology, Egmore, refer the affected to appropriate centres for treatment and rehabilitation and assess the feasibility of implementation of a similar project on a larger scale.

"The incidence is more in consonance with Western data than we had initially expected in the context of problems like low-birth-weight babies," said principal investigator, Ravi Ramalingam, of KKR ENT Hospital and adviser to WHO. The accepted figure for worldwide incidence of severe hearing impairment is between three and five per thousand live births.

Very little data

The pilot study is attempting to piece together for the first time basic information about a disorder on which there is very little data available in the country. It is almost routine in clinical practice for ENT specialists to review a condition of deafness very late, sometimes when children are 10 years old or more.

The results — in terms of providing near normal hearing and rehabilitation — are best if treatment as early as possible, as in the absence of hearing speech does not develop and aggravates the trauma of the victim.

The larger aim of the study is to broadbase screening for deafness in the country and eventually put in place the practice of universal hearing screening so that appropriate treatment is launched early. In most developed countries, hearing screening of newborn is already mandatory.

The study is mid-stage and the final results are expected to be out by September. It was launched last year after the Government cleared the participation of the Institute of Obstetrics and Gynaecology at a meeting chaired by Health Secretary, Sheela Rani Chunkath. More than 2,500 newborns have been screened using the Distortion Product Oto Acoustic Emission Testing equipment at the maternity hospital. Parents of children who fail the hearing test are asked to bring the patient to the KKR ENT Hospital for review after three months.

The screening programme will analyse the link between hearing impairment and health status. The high-risk babies include those born preterm, afflicted by jaundice, low-birth-weight and children of mothers carrying infection. These high-risk children are more likely to have a hearing impairment, doctors said.

"Low-birth-weight is most common complication that we see and constitutes about two-thirds of the admissions and one-third of deliveries at the institution," N. Saraswathi, Head of Neonataology, Institute of Obstetrics and Gynaecology.

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