Poor quality blood spots could lead to false negative or false positive results. This means babies with a condition might be missed or babies without a condition might be referred for further tests unnecessarily.
Avoidable repeat samples can cause anxiety for parents, distress to babies and delays in the screening process. This could lead to delayed identification and treatment of an affected baby.
What’s in the guide
The updated newborn blood spot sampling guidelines: quick reference guide explains how to take a newborn blood spot screening sample. It also includes example images of correct and incorrect blood spot samples and what to do after taking the sample.
Do not delay screening movers in if they are not registered with a GP – child health information services (CHIS) can generate an NHS number but some have not been commissioned to perform this function.
Babies born pre-term or cared for in specialist units
On admission, or prior to blood transfusion, babies less than 5 days of age should have a single circle blood spot sample taken. Mark the blood spot card as ‘pre-transfusion’.
Despatch the ‘pre-transfusion’ sample to the screening lab with the routine day 5 sample if the baby has received a blood transfusion in the interim.
When a baby has had a blood transfusion, wait at least 3 clear days before taking the routine blood spot sample.
However, in the event of multiple blood transfusions, or if a baby is on extra corporeal membrane oxygenation (ECMO), a routine blood spot sample should be taken by day 8 at the latest (even if it has not been 3 clear days since the last transfusion).
In this scenario, a repeat sample will be needed at least 3 clear days after the last transfusion or the end of ECMO. The date of the last blood transfusion or end of ECMO must be recorded on the blood spot card.
Although not covered in the quick reference guide, the comments box on the blood spot card should be used for information such as:
- family history of conditions screened for
- biological parents’ sickle cell and thalassaemia (SCT) carrier status
- mover in baby
- nipple cream used by mother, as this can result in false positive isovaleric acidaemia (IVA)
- congenital hypothyroidism (CHT) preterm day 28/discharged home sample
- repeat sample for inconclusive cystic fibrosis (CF)
- repeat sample for borderline CHT
- screening declined (specify which conditions and see guide for additional steps when screening is declined)
- no research contact
PHE Screening blog
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