Newborn Screening Information for Providers:
Blood Spot Collection

On this page:Blood spot collection
Personnel
Timing
Blood Spot Collection
Putting Babies First video


Personnel

Blood spot collection can be performed by trained personnel such as hospital nursery staff, laboratory staff, or out-of-hospital birth providers.


Timing

Timing of blood spot collection is important for accurately interpreting test results. Tests for some of the disorders on the newborn screening panel have different cutoff values based on the infant’s age (in hours) at the time of blood spot collection. As a result, blood spots drawn too early or too late may increase the chance of false positive or false negative results.

Blood spots are best collected between 24 and 48 hours of age. Blood spots collected before 24 hours of age cannot be fully interpreted, which means some test results will be marked “unsatisfactory” on the newborn screening report. An unsatisfactory result will require another blood spot collection. Blood spots collected after 48 hours may not allow enough time for results to be interpreted before serious symptoms occur in newborns affected by certain disorders on the newborn screening panel. However, special circumstances may arise that require blood spot collection at earlier or later times. Please reference the Minnesota newborn screening Provider Manual for more information on the timing of bloodspot collection.


Blood Spot Collection

The MDH Newborn Screening Program uses blood collection standards developed specifically for newborn screening programs by the Clinical and Laboratory Standards Institute.

The primary goal of these standards is to ensure the quality of blood spots collected from newborns. Poor quality specimens place an unnecessary burden on the birth provider, potentially delaying the detection and treatment of an affected infant. When the MDH Newborn Screening Program receives a specimen of poor quality, program staff requests a repeat sample from the birth provider.

Proper specimen collection technique as outlined by the Clinical and Laboratory Standards Institute include the following steps:

  1. Ensure that the expiration date of the newborn screening card has not passed. Complete the required patient information fields requested on the demographic data portion of the card. Avoid touching the area within the circles on the filter paper section before, during, and after collection of the specimen, since oils and other materials from the hands might affect or contaminate the card or specimen. Do not allow water, feeding formulas, antiseptic solutions, glove powder, hand lotion, or other materials to come into contact with the specimen card before or after use.

  2. Blood collection from the heel is the standard for newborn screening. The medial and lateral parts of the underfoot are preferred. Blood should never be collected from:
    • -the arch of the foot
    • -the fingers
    • -the earlobes
    • -a swollen or previously punctured site
    • -IV lines containing other substances (TPN, blood, drugs, etc.)
  3. Warm the heel with a warm damp cloth or commercially available heel warmer and position the leg lower than the heart to increase venous pressure before collecting the sample. The infant should be swaddled in a blanket with only one foot exposed. Powder-free gloves are best worn while collecting the blood spots. Lotion, Vaseline, and other substances, which can interfere with blood spot analysis, should be kept off the infant’s skin. Wipe the skin clean with an alcohol wipe and allow to thoroughly air dry.

  4. Use a sterile lancet or heel incision devise to make an incision 1 mm deep and 2.5 mm long. When collecting from small, premature infants, it is safer to make a more shallow incision.

  5. Wipe away the first drop of blood with a sterile gauze pad. Allow a large drop of blood to form. Using the thumb to intermittently apply gentle pressure to the heel may be helpful in encouraging the drop to coalesce.

  6. Touch the first circle on the newborn screening card gently against the large blood drop, and in one step, allow the blood to soak through the filter paper and fill the circle. Do not press the paper directly against the baby’s heel. Each of the five circles needs to be filled and saturated through. Apply the blood from only one side of the filter paper. It does not matter whether the blood is applied to the front or back of the filter paper.

  7. Do not apply multiple layers of blood drops to the same circle. The circles are measured and should contain a set volume of blood. Layering can interfere with the accuracy of the test by providing a non-standard amount of blood or non-uniform analyte concentration. Excessive milking or squeezing of the puncture site can result in an unsatisfactory specimen because of hemolysis breaking down the blood cells to be analyzed or mixing tissue fluids in the specimen, which can dilute the blood.

    Simple Spot Check (PDF: 130KB/1 page)
    Diagram of unsatisfactory specimens.

  8. Allow the specimens to dry flat at room temperature for at least 3 hours. This is essential to maintaining the integrity of the blood spots. Keep them out of direct sunlight and away from other heat sources. Do not allow them to touch other surfaces or specimens. Avoid stacking the cards. Do NOT close the biohazard flap over the spots until they are completely dry.

  9. Once the blood spots have completely dried, the biohazard flap can be closed and the newborn screening card can be sent to the Newborn Screening Program. Institutions that regularly submit specimens should have a procedure in place for pick-up by courier or other shipper established through the Newborn Screening Program. The Newborn Screening Laboratory accepts specimens Monday through Saturday at the address below. The Newborn Screening Program accepts deliveries even during weather emergencies, outbreaks, or government shutdowns; therefore blood spots should continue to be collected and delivered during these times. For questions about holiday deliveries or if special delivery plans are needed, contact Newborn Screening Program staff.

Delivery Address:
Newborn Screening Program
601 Robert St. N
St. Paul, MN 55155

For clinics, out-of-hospital birth attendants, and parents who submit specimens infrequently, specimens can be brought to the delivery address above or mailed to the address below. Since high heat and humidity can affect some of the tests, leaving specimens in hot mailboxes or other warm locations should be avoided.

Mailing Address:
Newborn Screening Program
P.O. Box 64899
St. Paul, MN 55164

Multiple newborn screening specimens may be sent together; however, a shipment should never be delayed or “batched” to wait for additional specimens. Additionally, newborn screening specimens should never be placed in the same container as other specimen types traveling to the Public Health Laboratory.


Putting Babies First video

The following video answers many frequently asked questions about blood spot collection, including the optimal timing of collection, drying of blood spots, and methods of collection. The video was produced in partnership by the Iowa State Hygienic Laboratory and Baby's First Test.

Note: This video is based on Iowa’s newborn screening protocol. Although the video states that a repeat newborn screen should be collected eight weeks after an infant’s last transfusion, the Minnesota Newborn Screening Program recommends that a repeat specimen be collected 90 days after the last transfusion. Please feel free to contact the Newborn Screening Program with any questions.