NEONATAL SCREENING FOR CONGENITAL HYPOTHYROIDISM IN RIYADH - ANALYSISOF 6 YEARS EXPERIENCE

The regional screening program for congenital hypothyroidism (CH) in R iyadh Province was started as a pilot study in December 1988. By Septe mber 1990, the program covered all deliveries at the MiniPstry of Heal th (MOH) and King Saud University hospitals. The program utilizes cord serum thyroid-stimulating hormone (TSH) with a low recall rate of 0.1 %. The average cost per specimen was SR 12 (US$ 3.20). Among 283,647 i nfants screened, 83 infants were confirmed to have CH (incidence 1:341 7). In 17 infants, however, the diagnosis was not confirmed due to dif ficulties in recall. Eleven infants with cord serum TSH of more than 1 00 mU/L proved to be clinically and biochemically euthyroid at recall. Three of these were secondary to maternal propylthiouracil (PTU) ther apy. The female to male ratio was 1.5:1. The majority of infants lacke d clinical symptoms and signs of hypothyroidism Thyroid scans showed t he most common etiology to be thyroid ectopy (50%), followed by dyshor monogenesis (26%) and athyrosis (24%). Although there was no significa nt difference in the mean cord T-4 values among the different groups, the mean T-4 value at recall in the athyrotic group was significantly (P < 0.001) lower than the cord results (14.8 versus 62.7) and that is of recall for the ectopic and dyshormonogenesis groups (14.8 versus 4 7.0 and 51.3 respectively). There was no significant difference in the mean TSH among the different groups in the cord and recall samples. S keletal maturation was more delayed in the athyrotic group. The mean a ge at the time of recall was 16.4 days (range 4 to 64), and the mean a ge at the start of therapy was 17.8 days (range 5-64).