Blood for the newborn metabolic screening test is collected on a blood spot card, sometimes known as a “Guthrie” card.

When testing of the blood sample is completed, the card with the leftover blood is either stored indefinitely in secure storage by the programme, or returned at the request of the family/guardian or the individual.  To request a card back, use the form 'Return of newborn metabolic screening samples (guthrie cards) to family'

What can stored blood spots be used for?

Once screening is completed, stored leftover blood spots may be used for the purposes on this page. These uses are rare, but they can help families/whanau and the programme.

Confirmatory testing

Sometimes the blood is re-tested, if the first result was unclear.

Investigating unexplained illness or death in a family/whanau

If a person dies for an unknown reason, a blood spot card can sometimes be tested to try and identify the cause. This is arranged by a doctor, with consent from family/whanau.

Sometimes medical research leads to the development of tests for disorders that were not available when the person died. This may provide valuable information for families/whanau about the cause of death and can provide families/whanau with information about their risk of other family members with that disorder.

Investigating false positive and negative results

Screening is not 100% accurate, and can give false negative and false positive results.

A false negative result is when a screening test puts a person in the low risk group for a disorder, but they are later found to have the disorder.

A false positive result is when a screening test puts a person in the high risk group for a disorder, but they are later found not to have the disorder.

The Newborn Metabolic Screening Programme aims to keep screening results as accurate as possible by reducing the number of false positive and negative results. Leftover blood spot samples may be used to investigate the cause of false positive and negative results. This helps improve the accuracy of the screening.

Quality assurance monitoring and evaluation

Leftover blood spots may be used to monitor the screening programme for quality assurance purposes.

Making improvements to the screening programme

Leftover blood spots may be used to make improvements to the programme (eg testing equipment for accuracy).

Forensic use

Very rarely, the New Zealand Police, usually with consent from family/whanau, request access to a specific blood spot card to identify a deceased or missing person or for coronial inquiries. For instance, Police may request a blood spot card to identify a body burnt in a house fire, or to identify victims of a natural disaster. Blood spots have also been used in criminal cases to identify victims.

The Ministry of Health and the New Zealand Police have signed a Memorandum of Understanding that sets out the framework for Police requests for access to the blood spots. The Memorandum came into effect in February 2006.

For more information see the 'Memorandum of Understanding between the Ministry of Health and the New Zealand Police relating to the disclosure of newborn blood spot cards and related information'.

Research projects

The Code of Health and Disability Services Consumers’ Rights 1996 allows residual blood spots to be used for research that is approved by an ethics committee.

By court order

Blood spot cards held by the Newborn Metabolic Screening Programme are the same as hospital records or medical files held by doctors in relation to the powers of the Court to order access or use the sample or information. In rare circumstances the Court can order access to blood spots for the purpose of testing.

Public Consultation on Newborn Blood Spot Cards: Consent, Storage and Use

The NSU consulted with the public in 2007.

Newborn Metabolic Screening Programme Focus Groups Report 2007

NMSP Advisory Group Report July 2008