A review of the case for neonatal thyrotropin screening in developing countries: the example of India.

Abstract

Infantile hypothyroidism, either caused by iodine-deficiency disorder (IDD) or congenital hypothyroidism (CH), is the world's leading cause of preventable mental retardation. Such hypothyroidism has virtually been eliminated in the developed world by salt iodization and neonatal thyroid screening. However, most developing countries do not have neonatal thyroid screening programs. Using India as an example, we review the case for newborn screening in the developing world. A literature review on infantile hypothyroidism in India was conducted and three Indian thyroid experts were queried about their views on neonatal screening in India. Iodine nutrition improved markedly in India during the 1990s; 49% of the households are now using adequately iodized salt. The control of IDD is still insufficient in India. Nationally representative data on neonatal screening in India are not available, but two regional studies have been published. One study (n = 12,407) measured cord blood thyrotropin and the other (n = 25,244) measured filter paper thyroxine. These studies reported difficult socioeconomic and organizational barriers to the implementation of neonatal screening in India. It is time for India to make neonatal thyroid screening and mandatory iodization of salt a priority and develop a comprehensive infantile hypothyroidism policy. Prioritization of infantile hypothyroidism prevention is justified by its high frequency, sensitivity of screening in detecting both IDD and CH, adverse consequences of missing diagnosis at birth, high effectiveness of prevention, severity of disability from hypothyroidism, cost effectiveness of prevention, and lack of a clinical method of diagnosis near birth.