Congenital hypothyroidism: the Riyadh Military Hospital experience.

OBJECTIVE

We aimed to find out the incidence of primary congenital hypothyroidism (CH) among infants born within the Riyadh Al-Kharj Hospital Programme in addition to early detection and treatment of these infants.

DESIGN

All babies born within the Riyadh Al-Kharj Hospital Programme were screened by cord blood TSH. Blood spot TSH were done in the majority of infants between 2 and 5 days after birth. All suspected cases were recalled for confirmatory tests. 123I thyroid scan and X-ray of the knee and maternal blood for thyroid antibodies were done for confirmed cases.

MEASUREMENTS

A cut off TSH level of 30 mIU/l for cord blood and 25 mIU/l for spot blood were used. All samples were assayed by immunoassay methods.

RESULTS

44,778 (99.4% of the total births) infants were screened. Twenty-five cases were detected, four of which were excluded. The incidence of primary congenital hypothyroidism was 1/2096. Five cases were missed on the initial screen. Eight out of 17 children who had 123I thyroid scan were found to have dyshormonogenesis. Associated malformation and diseases were diagnosed in 42.85%. Two had chromosomal anomalies; ring chromosome 9 has not been previously reported in association with congenital hypothyroidism.

CONCLUSION

The incidence of congenital hypothyroidism, dyshormonogenesis and the associated malformations and diseases are higher than those reported in the literature. Cord blood as a screening method is associated with a significant number of missed cases.