Neonatal Screening for Congenital Hypothyroidism: Incidence, Imaging, Feasability, and Difficulties of a Nationwide Program

Abstract

A pilot project was carried out in Riyadh to study the incidence and pattern of congenital hypothyroidism (CH) among newborn delivered at the Ministry of Health (MOH) hospitals. Cord blood was assayed for thyroid stimulating hormone (TSH). For affected infants, Tc-99m pertechnetate thyroid scintigraphy and perchlorate discharge test (PDT) using I(123) were performed to determine the caused of congenital hypothyroidism. Fifteen affected newborns were diagnosed among 40,000 newborns screened giving an incidence of 1:2666. Tc-99m thyroid scan revealed athyreosis in five infants; the thyroid gland was ectopic in eight and thyroid in two infants. In eight infants thyroid tissue was visualized, PDT was performed and the test was positive in seven cases (two eutopic and five ectopic). We concluded that the incidence of CH was higher compared with other parts of the world. Thyroid scintigraphy has a primary role in the evaluation of infants with congenital hypothyroidism and should be part of the protocol for the screening program. As early initiation of thyroxine therapy will prevent neurological and physical handicaps of the disease, the decision was made to have a nationwide screening program established in Saudi Arabia. The organization and difficulties of the screening program are being discussed.