Overview: Ultrasensitive TSH Cord Blood TestIntroduction: The Ultrasensitive TSH Cord Blood Test measures TSH in cord blood to diagnose neonatal thyroid issues, causing developmental delays. Following 2023 AAP guidelines, it uses biochemical methods for high sensitivity, supporting newborn screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in endocrinology for newborns with suspected thyroid disorders.
Other Names: TSH Cord Blood Assay, Neonatal TSH Test.
FDA Status: Laboratory-developed test (LDT), meeting endocrinology standards for diagnostic accuracy.
Historical Milestone: Neonatal TSH testing began in the 1970s with congenital hypothyroidism research. Ultrasensitive methods improved in the 2000s, enhancing precision.
Purpose: Measures TSH in cord blood to diagnose neonatal thyroid issues, guides treatment, and evaluates developmental delay risk.
Test Parameters: 1. TSH Level
Pretest Condition: Fasting for 10-12 hours required for mother. Collect cord blood or plasma. Report family history of thyroid disorders.
Specimen: Plasma (EDTA, 2-4 mL), Cord Blood (EDTA, 2-5 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 24 hours
Sample Stability at Frozen: Not frozen
Medical History: Document family history of thyroid disorders or neonatal developmental issues. Include maternal medications, especially thyroid-related.
Consent: Written consent required, detailing the tests purpose, neonatal thyroid disorder implications, and risks of sample collection.
Procedural Considerations: Uses high-sensitivity chemiluminescence to measure TSH in cord blood. Results are available in 1-2 days, supporting clinical decisions. Performed in laboratories, often for newborn screening.
Factors Affecting Result Accuracy: Improper sample collection or maternal medications can affect results. Prematurity may alter TSH levels.
Clinical Significance: Elevated TSH confirms neonatal hypothyroidism, guiding thyroid hormone replacement. Normal levels may require repeat testing or free T4.
Specialist Consultation: Consult a pediatric endocrinologist for result interpretation and treatment planning.
Additional Supporting Tests: Free T4, thyroid ultrasound, or newborn screening panel to confirm neonatal thyroid disorder diagnosis.
Test Limitations: Non-specific for certain thyroid conditions; clinical correlation is needed. Sample quality affects sensitivity.
References: AAP Newborn Screening Guidelines, 2023; Pediatrics, Wassner AJ, 2022.
