Congenital anomalies in infants with congenital hypothyroidism: is it a coincidental or an associated finding?

During the period between December 1988 and February 1995, a total of 279,482 newborn infants were screened in the regional neonatal screening program for congenital hypothyroidism (CH) in Riyadh province, Saudi Arabia. Eighty-one infants were confirmed to have CH giving an incidence of 1 in 3,450. Variable congenital anomalies, other than those of the thyroid gland, were present in 16 (19.8%). The anomalies most frequently encountered were congenital heart defects (7), unclassified multiple congenital anomalies (5) and Down's syndrome (2). The results of our study confirm this association, and emphasize the need to search for such anomalies in infants born with CH. Nationwide studies, however, on birth defects in the general population and those associated with CH are still needed to help us understanding the role of local genetic and environmental factors.