Office of Newborn Screening
Testing & Specimen Collection – Collection Process
Each disorder has a best screening window where the test is most likely to detect affected infants while minimizing false positive results. These windows are much earlier than those recommended in the past because the disorders detected by tandem mass spectrometry can be accurately detected by 24 hours of age, Early collection, with no delays in handling or shipping, provides the best chance for a disorder to be detected and treated timely. The bottom line—early collection, with no delays in handling or shipping, gives the best chance for a disorder to be detected and treated before an infant is permanently harmed.
Special considerations should be given sick, pre-term and low birth weight babies have their own complications for screening and even earlier collection is recommended to avoid interference from therapies like transfusion, parenteral nutrition or treatment with steroids and some antibiotics. Additionally, a third screen may be indicated if he infant was on parenteral nutrition at the second screen.
- Order Specimen Collection Kits
- Collection Kit Demographics
- Specimen Collection Instructions
- Factors Affecting Test Results or Interpretation
- Sample Test Result Mailers, Letters, and Discussion Follow-Up
- Specimen Rejection Quick Reference
- Testing & Specimen Collection
Collection and Handling of First Screens
You can collect a perfect specimen but if it wasn't collected during the recommended screening window, or if it was delayed in transport to the State Lab, a baby could suffer.
When is the best time to collect a first specimen? The best time to collect a first specimen is 24 to 36 hours of age—earlier is now better.
- Best Screening Window
- Each disorder has a best screening window where the test is most likely to detect affected infants while minimizing false positive results. These windows are much earlier than those recommended in the past because the disorders detected by tandem mass spectrometry can be accurately detected by 24 hours of age and some of them can harm babies in the first few days of life (so earlier screening is needed).
- Arizona Rules
- The Arizona Administrative Code R9-13-204 states that a first specimen must be collected between 24 and 72 hours of age, but collection closer to 24 hours is recommended. For all disorders except homocystinuria, ideal screening windows include the time between 24 and 48 hours of age. Waiting until 72 hours is already past the best window for many disorders.
- Special Considerations
- Sick, pre-term and low birth weight babies have their own complications for screening and even earlier collection is recommended to avoid interference from therapies like transfusion, parenteral nutrition or treatment with steroids and some antibiotics.
How can delays in transport to the Arizona State Lab be prevented?
- Prompt Mailing
- The Arizona Administrative Code R9-13-203 A. 4 states that specimens must be sent to the State Lab within 24 hours of collection or the next business day.
- Hospitals Using FedEx (state paid), Courier or US Mail
- Each hospital should identify someone with the responsibility to ensure that samples move quickly from the nursery to the lab and shipping area so that the whole process from collection to shipping takes 24 hours or less. The practice of "batching", where a facility delays sample shipment until a predetermined number of samples is collected, seriously increases the risk of irreversible harm or death for those infants born earliest in the batch. Therefore, any hospital with at least one birth a day should send a shipment of samples to the State Lab each weekday, including Friday.
- Other Providers
- For those providers who don't attend at least one birth a day, the requirement is still to ship as promptly as possible. A single specimen sent alone is acceptable and shouldn't be held to be sent with others collected on a later date.
Collection and Handling of Second Screens
When is the best time to collect a second specimen? The best time to collect a second specimen is 5 to 10 days of age or at the first outpatient visit to the doctor. Since babies often see their primary care physicians prior to 5 days of age, second screens should be collected at that visit, even though the baby is not yet 5 days old.
Second specimens can be collected after 10 days of age (and will be tested if collected up to a year of age). However, later-collected specimens may miss cases of certain metabolic disorders (e.g., VLCAD, MCADD, GA-1) or cystic fibrosis because false negatives are more likely in older babies. For disorders where symptoms are not apparent until irreversible damage has been done (PKU, congenital hypothyroidism) later detection would mean a poorer outcome for an affected infant.
- For providers who collect their own second screens:
- Collect the specimen at the baby's first visit and send it to the State Lab as soon as it is dry. A single specimen is acceptable and shouldn't be held to be sent with others collected on a later date.
- Protect specimens from heat and sunlight. Don't put them in metal collection boxes on outside doors during the summer or drop them in an outside mailbox in the sun.
- For providers who send patients to an outside lab:
- Please direct your patients to get the second screen collected as soon as possible.
- We have heard that some labs are turning families away if the baby is younger than 2 weeks of age. This should not happen since earlier collection is now recommended. The Office of Newborn Screening will be working with the large contract labs to ensure that all of their drawing stations have the latest guidelines. Please let us know if you hear of any parents that have been turned away.