Congenital Hypothyroidism Screening Program: A Five-Year Experience at Saudi Aramco Al Hasa Health Center

Abstract

We report the results of a five-year study of cord blood screening for congenital hypothyroidism in a genetically homogeneous population in the Eastern Province of Saudi Arabia. The prevalence of congenital hypothyroidism was 1/5061 and is compared to other reports. The prevalence of dyshormonogenesis was 1/7592, higher than in other reports. Ann Saudi Med 1996;16(1):47-49. HH Narchi, NA Kulaylat, Congenital Hypothyroidism Screening Program: A Five-Year Experience at Saudi Aramco Al Hasa Health Center. 1996; 16(1): 47-49 Detection of congenital hypothyroidism by neonatal screening programs has been extensively studied in developed countries. Its prevalence shows marked geographical and racial variations. We report our experience over a five-year period in the neonatal screening program for hypothyroidism, undertaken at Saudi Aramco Al Hasa Health Center between 1988 and 1992. Material and MethodsAll infants born at Saudi Aramco Al Hasa Health Center between January 1988 and the end of December 1992 were screened for congenital hypothyroidism. Our facility provides medical care for family members of Saudi Arab Aramco employees living in the Al Hasa area of the Eastern Province of Saudi Arabia. This population is genetically homogeneous and the prevalence of diseases can readily be compared with any other population.Cord blood samples were collected from the placental side at birth and were assayed for thyroxine (T4) levels by Fluorescent Polarization Immunoassay (Abbott Laboratories, Illinois, USA). For infants born outside our facility, the test was carried out on blood spot on filter paper simultaneously with PKU testing at their first visit to our facility, usually within a few days of birth. Cord blood T 4 values below 6.0 μg/dL (>2 SD below the mean for this population) were considered abnormal and cord blood thyrotropin (TSH) was measured by Microparticle Enzyme Immunoassay (Abbott Laboratories, Illinois, USA) on the same blood sample. All infants with low T 4 levels were called for clinical evaluation and had a repeat venous blood T 4 , TSH and free T 4 estimation. The lower limits (>2 SD) of repeat serum levels were defined as T 4 6.1 μg/dL, TSH 7.5 μU/mL and free T 4 0.78 ng/dL. Infants with low T 4 and high TSH were considered to have primary hypothyroidism, those with low T 4 and low TSH were considered to have secondary or tertiary hypothyroidism, while those with low T 4 accompanied with normal TSH (and normal free T 4 ) were considered to have thyroxine-binding globulin (TBG) deficiency, either congenital or acquired.The infants with confirmed hypothyroidism were started on treatment, then referred to a pediatric endocrinologist. A T 3 withdrawal test and technetium-99m pertechnetate thyroid scintigraphy are carried out after the age of three years to confirm the persistence and type of hypothyroidism. ResultsBetween January 1988 and December 1992, a total of 15,185 Saudi Arab neonates were screened for congenital hypothyroidism. A total of 363 infants had initial low T 4 values (2.39% of all ...

Diagnosed congenital hypothyroidism with missing follow-up: Is it time for a national registry?

“… 6 Reports from other regions of Saudi Arabia suggest that the incidence of CH is 1 in 2500 to 3500. 7 – 9 These figures are comparable with the worldwide incidence of CH. The high incidence of CH in the Saudi population supports the need for a neonatal screening program.…”

Influence of perinatal factors on thyroid stimulating hormone level in cord blood

“…[111213] Currently in some countries it has been chosen for the methods of choice in the screening program. [14]…”

Is Umbilical Cord Blood Total Thyroxin Measurement Effective in Newborn Screening for Hypothyroidism?

“…The incidence of primary congenital hypothyroidism in our population is 1:3692, which is similar to the published international figures, but lower than those published by other programmes in Saudi Arabia (1:2666 by Ministry of health hospitals and 1:2759 by Military hospitals). 8 This may be explained by the fact that our rate reflects the true incidence of confirmed primary congenital hypothyroidism. Our cord blood screening programme detected 32 cases of primary congenital hypothyroidism.…”

“…8 This may be explained by the fact that our rate reflects the true incidence of confirmed primary congenital hypothyroidism. Our cord blood screening programme detected 32 cases of primary congenital hypothyroidism.…”

“…2 All of these factors make use of umbilical cord blood a practical alternative for thyroid screening purposes. 6–8 Interestingly, some countries revert to cord blood screening as the method of choice, when facing difficult patient recall for initial thyroid testing. 9,10…”