The birth of your child is a life-changing event that will live on in your memory for the rest of your life. It also may be a frenetic time with a lot of important medical details to attend to. Your infant has several initial examinations to make sure they are well. The baby receives a first vaccine, and importantly, newborn screening tests are done.
A newborn screening test is a public health service performed in each state throughout the United States. Each newborn is tested for a specific group of health disorders that might otherwise go undetected.
A simple blood test checks for rare genetic, hormone-related, and metabolic conditions that could potentially cause serious health problems for the child if the condition was not discovered.
Newborn screening allows doctors to diagnose babies quickly, and to start treatment as soon as possible.
What Newborn Screening Tests Are Performed?
The specific screening tests performed can vary from one state to the next. The tests offered might change over time as technology advances and treatments improve. Tandem mass spectrometry, which you might recognize as “Major Mass Spec” from the TV show “NCIS”, is a test that detects molecules by measuring and comparing their weights. Mass Spec has made identification of rare enzymes, proteins and other molecules much easier than ever before.
Although there are national recommendations for newborn screening, ultimately it is up to each state to decide which tests to include in the public health newborn screening. Certain criteria are used when determining if a condition should be included:
- Is the condition serious?
- Will delay of diagnosis and lack of treatment lead to greater morbidity and even mortality?
- Is effective treatment available for the condition?
- If the condition is diagnosed early and treatment instituted early, are there better outcomes?
- Is there a reliable screening test for the condition with low false positive rates?
- Is the test adaptable to large numbers of people at low cost?
- Are the results available in a timely manner?
- Are there follow up tests to identify “true positives”?
What Conditions Do Newborn Screenings Look For?
While it can vary, most newborn screening includes tests for metabolic problems and disorders, endocrine (hormone) problems, hemoglobinopathies, and other rare but serious disorders.
Metabolic Problems & Metabolic Disorders
Metabolism is the process that converts food into energy for the human body to move, think, and grow. There are special enzymes that help with metabolism by speeding up the chemical reactions in cells.
Metabolic disorders occur when certain enzymes are missing or not working as they should. Metabolites can accumulate leading to illness. Because of this, your newborn’s screening will include tests for the following conditions.
- Phenylketonuria (PKU)
- Methylmalonic acidemia
- Maple syrup urine disease (MSUD)
- Medium-chain acyl CoA dehydrogenase (MCAD) deficiency
Hormone Problems & Hemoglobinopathies
Hormones play a critical role in healthy growth and development from the very earliest stages of life. They are essentially chemical messengers made by glands. Many hormone problems arise when the target organ makes too much or not enough of the hormone. An example of this is congenital hypothyroidism, in which mature thyroid hormone is produced in short supply. Thyroid hormone is critical for normal growth and development during the first years of life. The conditions can be severe if not recognized early.
Typical newborn screening for hormone problems includes testing for the following conditions:
- Congenital hypothyroidism
- Congenital adrenal hyperplasia
Hemoglobinopathies or disorders of hemoglobin, the oxygen carrying molecule in red blood cells, can be detected at birth through neonatal screening. Some of these include:
- Sickle cell disease
- Hemoglobin SC disease
- Beta thalassemia
- Other Hemoglobin problems
Rare & Potentially Serious Conditions
A newborn screening test will also look for signs of a few rare, but potentially serious conditions. The most common of these is cystic fibrosis, but others might include:
- Biotinidase deficiency
- Severe combined immunodeficiency (SCID)
- Pompei disease
- Glycogen storage disease type II
- Mucopolysaccharidosis type 1
- X-linked adrenoleukodystrophy
- Spinal muscle atrophy (SMA)
Hearing & Heart Tests
Many states also screen for hearing loss and critical congenital heart defects. These are exams that can be performed in a matter of minutes at the bedside in the first day or two of your baby’s life before you leave the hospital.
Hearing is tested using either otoacoustic emissions or auditory brain response. A stimulus or sound is introduced into the baby’s ear and a response measured. The baby needs to be quiet or still for the exam to be successful.
Testing for cyanotic congenital heart disease is done by measuring the pulse oximeter reading on both sides of the child’s body (usually the hands or feet). A discrepancy of more than a few percent could mean that there is mixing of blood in the heart, and further testing is needed to rule out heart disease.
You should talk to your pediatrician if you feel that your baby may need other newborn screening tests not offered through your state program.
How Is Newborn Screening Performed?
A typical newborn screening starts with extracting a very small blood sample taken by pricking the baby’s heel. This tiny volume is all that’s needed to run an extensive battery of tests and look for endocrine and other health conditions.
This heel prick blood test usually happens before the baby leaves the hospital, usually at 1 or 2 days of age, and almost always after the baby has been feeding for 24 hours (so that trace enzymes associated with feeding and digestion can be detected). You should talk to your pediatrician about scheduling a public health newborn screening if your baby was born at home or a location other than a hospital.
If mother and baby are discharged prior to 24 hours and the first newborn screening sample was drawn early, most experts recommend taking a repeat sample no more than 1 to 2 weeks later. Some US states routinely do two tests on all newborn infants.
How Long Does It Take To Get Results For A Newborn Screening Test?
Newborn screening for hearing loss and congenital heart defects are available as soon as the tests are done at the bedside.
The results from the heel prick blood test usually are ready by the time a baby is 5 to 7 days old. Many times the parents won’t hear about results if screening tests were normal. So, this is a case where “No News, Is Good News”.
You and your pediatrician will be contacted promptly if a test is positive for any one of the screened conditions. However, it’s important to note that a positive result on a newborn screening test does not necessarily mean that your child definitely has the medical condition. Instead, it indicates to physicians that they need to order more tests to confirm or rule out the diagnosis.
If further testing does not rule out the condition, your physician will likely refer your newborn to a specialist for more testing. In a case where treatment is needed, it is important to start as soon as possible. Treatment might include special formula, diet restrictions, supplements, medications, and close monitoring.
Is A Newborn Screening Test Covered By Insurance?
Newborn screening tests are typically included in the birthing and delivery costs, which are fully covered by insurance. If you don’t have health insurance, public health institutions in your state will likely have provisions to help cover the cost of newborn screening.