Newborn Screening in the US May Miss Mild Persistent Hypothyroidism

Area of Science:

• Endocrinology
• Neonatal screening
• Public health

Background:

• Congenital hypothyroidism (CH) screening is crucial for early intervention.
• Thyroid-stimulating hormone (TSH) levels naturally decrease in newborns within the first few days of life.
• Standardized screening protocols are essential for effective CH detection.

Purpose of the Study:

• To evaluate whether US newborn screening (NBS) programs utilize age-adjusted thyroid-stimulating hormone (TSH) cutoffs for congenital hypothyroidism screening.
• To determine if current NBS practices account for the physiological decline in TSH levels after birth.

Main Methods:

• Survey of all US NBS programs regarding their protocols for congenital hypothyroidism screening.
• Inquiry into the specific TSH cutoffs used and whether they are age-adjusted.
• Analysis of data from 51 NBS programs across the United States.

Main Results:

• Significant variation exists in NBS practices for CH screening nationwide.
• Many programs (16/28 with discretionary repeat and 8/14 with routine repeat) do not employ age-adjusted TSH cutoffs beyond 48 hours of life.
• Repeat specimens are often collected between 1 week and 1 month, but without age-specific TSH thresholds.

Conclusions:

• Current NBS protocols for CH in the US exhibit considerable heterogeneity.
• Failure to implement age-adjusted TSH cutoffs beyond the initial 48 hours can lead to missed diagnoses of CH.
• Recommendations include adopting age-adjusted TSH cutoffs and developing a standardized US screening approach for CH.