Newborn Screening
General
Synonym/Acronym:
NBS, newborn metabolic screening, tests for inborn errors of metabolism, early hearing loss detection and intervention for newborns.
Rationale
To evaluate newborns for congenital abnormalities, which may include hearing loss; presence of heart defects; identification of hemoglobin variants such as thalassemias and sickle cell anemia; presence of antibodies that would indicate an HIV infection; or metabolic disorders such as homocystinuria, maple syrup urine disease (MSUD), phenylketonuria (PKU), tyrosinuria, and unexplained physical or intellectual disabilities.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.
Normal Findings
Method: Thyroxine, thyroid-stimulating hormone (TSH), and HIV—immunoassay; amino acids—tandem mass spectrometry; hemoglobin variants—electrophoresis.
Screening components may vary by state, but the core test program consists of hearing, heart, and blood screening tests. The age for screening is within 72 hr of birth (Neonates—3 days).
Hearing Test | |
---|---|
Age | Normal Findings |
Neonates–3 days | Normal pure tone average of –10 to 15 dB |
Heart Screen for Critical Congenital Heart Defects | |
Age | Normal Findings |
Neonates–3 days | Pulse Oximetry Test = Pass, Negative, or In Range |
Endocrine Disorders | Normal Findings | ||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
TSH for Primary Congenital Hypothyroidism | Less than 20 micro-international units/mL | ||||||||||||||||||||||||||||||||||||||||
Thyroxine, Total (Total T4) for Primary Congenital Hypothyroidism | 5.4–22.6 mcg/dL | ||||||||||||||||||||||||||||||||||||||||
17–hydroxyprogesterone (17–OHP) for Congenital Adrenal Hyperplasia | Less than 15.1 ng/mL | ||||||||||||||||||||||||||||||||||||||||
Hemoglobin Disorders | |||||||||||||||||||||||||||||||||||||||||
Sickle Cell Anemia (Hgb SS), Beta-thalassemia (Hgb SbetaTh), SC disease (Hgb SC) for Abnormal Hemoglobins | Negative for abnormal hemoglobins | ||||||||||||||||||||||||||||||||||||||||
Disorders of Amino Acid Metabolism | |||||||||||||||||||||||||||||||||||||||||
Blood spot analysis | Normal findings. Numerous amino acids are evaluated by blood spot testing, and values vary by method and laboratory. The testing laboratory should be consulted for corresponding reference ranges. | ||||||||||||||||||||||||||||||||||||||||
Disorders of Organic Acid Metabolism | |||||||||||||||||||||||||||||||||||||||||
Blood spot analysis | Normal findings. Numerous organic acids are evaluated by blood spot testing, and values vary by method and laboratory. The testing laboratory should be consulted for corresponding reference ranges. | ||||||||||||||||||||||||||||||||||||||||
Disorders of Fatty Acid Oxidation | |||||||||||||||||||||||||||||||||||||||||
Blood spot analysis | Normal findings. Numerous fatty acids are evaluated by blood spot testing, and values vary by method and laboratory. The testing laboratory should be consulted for corresponding reference ranges. | ||||||||||||||||||||||||||||||||||||||||
Infectious Disease Testing | |||||||||||||||||||||||||||||||||||||||||
HIV antibodies | Negative | ||||||||||||||||||||||||||||||||||||||||
Abnormal screening results are followed up with specific diagnostic testing. |
Critical Findings and Potential Interventions
N/A
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