Dried blood spot screening for congenital hypothyroidism supports newborn screening expansion in Pakistan
The study reports outcomes from a tertiary care hospital in Pakistan that introduced dried blood spot screening for congenital hypothyroidism. Among 53,799 neonates screened, 40 tested true positive, and 34 underwent standardized developmental assessment at three years. Early treatment was associated with normal growth and neurodevelopment in 94.1% of children, with only one case of global delay linked to an unrelated disorder. These results demonstrate that decentralized dried blood spot testing can reliably identify congenital hypothyroidism and prevent intellectual disability, offering a practical model for newborn screening expansion in low-resource settings.
The original study
Growth and Neurodevelopmental Outcomes of Children With Congenital Hypothyroidism Identified Through Dried Blood Spot Newborn Screening at a Tertiary Care Hospital in Pakistan.
- Authors
- Rehman B, Arif M, Akbar A, Mazhar N, Hoodbhoy Z, Memon F, et al.
- Journal
- Endocrinology, diabetes & metabolism
- Type
- Journal Article
- PMID
- 42632077
Original abstract
BACKGROUND: Congenital hypothyroidism (CH) is the most common congenital endocrine disorder and a leading preventable cause of intellectual disability in children. Pakistan lacks a national NBS program, and CH incidence is estimated at 1:1000-1:600, higher than the global average. AKUH, Karachi, introduced DBS screening for CH in 2019. This study assessed outcomes in neonates screened between 1 April 2019 and 31 March 2024. METHODS: Neonates with positive DBS (TSH > 10 μIU/mL) and confirmed CH (FT4 < normal and TSH > 20 μIU/mL) were included; growth and ASQ-3 records were extracted. RESULTS: Among 53,799 screened babies, 971 were screened positive; of these, 40 (4.12%) were true positives. Thirty-nine neonates were included; 34 had ASQ-3 records. Females were n = 23 (59%); median gestational age was 38 weeks, 82.1% had normal birth weight, and median birth weight was 2.8 kg. DBS was performed after 36 h in 64.1%. Eight neonates were symptomatic; prolonged jaundice occurred in 20.51%; one had trisomy 21; and eight (20.5%) had a family history of hypothyroidism. At 3 years, weight SDS ranged from -2.02 to 0.98 and height SDS from -2.15 to 1.65, with median height SDS of -0.62. Global delay was observed in one child (3%), fine motor and personal-social impairment in one child each (3%) and normal development in 32 (94.1%). CONCLUSIONS: The child with global delay was suspected to have an underlying neurometabolic disorder unrelated to CH. DBS screening at AKUH detected CH consistently with local estimates, and early treatment was associated with normal growth and neurodevelopment in most neonates at 2-year follow-up. These findings support NBS expansion in Pakistan.