4 Neonatal Specimen Collection

Choosing the collection method

Select the method according to the test, required volume, and laboratory instructions. Device requirements can differ, so follow the laboratory’s collection instructions and local policy.

Venipuncture is often preferred for term neonates when an experienced collector is available, particularly if more blood or several tests are needed. Heel-stick capillary collection is useful when only a small volume is required, including for many point-of-care tests and newborn screening, but capillary blood is not suitable for every test.

If capillary collection is unsuccessful or the requested volume exceeds what can appropriately be collected, stop repeated attempts and seek a suitable alternative under local policy.

Selecting a safe heel site

Use the medial or lateral plantar surface of the heel within the designated safe areas. Avoid the center of the heel, the posterior curvature, and any site with bruising, swelling, infection, or recent punctures. These precautions reduce the risk of injury to underlying structures and improve sample quality.

Choose a neonatal safety lancet with a depth appropriate for the infant’s size and the device instructions; do not assume one depth suits every newborn.

Performing the heel-stick collection

A careful sequence supports accurate identification, safe collection, and appropriate handling:

1. Verify the infant’s identity and requested tests. Gather the correct microcontainers or screening card.

2. Position and support the infant securely. Warm the heel only as directed by local policy and the warmer’s instructions.

3. Clean the site with the approved antiseptic and let it dry completely.

4. Puncture the selected safe area with one controlled use of the safety lancet.

5. For laboratory microcollection, wipe away the first drop unless the test or point-of-care device instructions say otherwise. Let a fresh drop form.

6. Touch the appropriate collection device to the drop. Use only gentle, intermittent pressure. Do not scrape, milk, or squeeze hard, because this may cause hemolysis, bruising, or tissue-fluid contamination.

7. Apply gentle pressure with clean gauze until bleeding stops, and dispose of the lancet immediately in a sharps container.

Filling, labeling, and handling specimens

Choose the microcollection device for the ordered test and fill it to the manufacturer’s required volume. Underfilling or overfilling additive tubes can alter the blood-to-additive ratio and affect test results. Cap tubes promptly and mix additive tubes gently as directed; do not shake them vigorously.

For multiple capillary specimens, a commonly recommended order is blood gases, EDTA, other additive tubes, then specimens without additives. Confirm the required order with the laboratory.

Label each specimen at the bedside according to facility policy, verify the label against the infant, and send it promptly under the test’s handling requirements. Record relevant collection details, such as collection time and, when required, gestational age, transfusion, or parenteral-nutrition information.

Special handling for screening and glucose tests

Newborn-screening blood spots must be collected according to the card instructions. Avoid layering drops or touching the paper to skin, and let the card air-dry completely before packaging.

For point-of-care glucose testing, follow the meter’s instructions for sample collection and whether the first drop should be used or discarded. Do not substitute a screening-card or microcontainer procedure for the method specified by the device.

Reducing pain and distress

Plan to reduce unnecessary punctures by coordinating ordered tests when appropriate, preparing supplies before starting, and using a trained collector.

Whenever feasible, use breastfeeding during the procedure, skin-to-skin care, or non-nutritive sucking. Swaddling or facilitated tucking can also help. Oral sucrose may be used under the neonatal unit’s protocol, with attention to individual contraindications. Comfort measures can be combined.