Newborn metabolic screening identifies babies who may have rare but serious disorders which are difficult to identify without a blood test. Your Lead Maternity Carer will discuss the screening test with you and ask for your consent for it to be done. During the test, a few drops of your baby's blood will be taken. The drops of blood from your baby's heel will be placed on the blood spot card and information relating to your baby will be written on the card. The blood test is carried out as soon after 48 hours as possible and sent to the National Testing Centre where over 20 disorders are tested.

What is the heel prick test?

The heel prick test takes blood from the baby's heel to test at a laboratory for certain metabolic disorders. After the baby's, mother's and LMC details have been entered into the blood spot card, the LMC will perform the test using a automated device (called a lancet). The heel puncture will be taken from the side of the baby's heel. The baby's foot will then be allowed to hang down to increase the blood flow and the circles on the blood spot card will be filled completely. After the heel prick is completed, gentle pressure is applied to the site using a cotton woll ball until the bleeding stops.

What are newborns screened for?

The heel prick test screens for over 20 metabolic disorders. They are grouped into three groups:

Amino acid disorders (for example PKU and MSUD)
Fatty acid disorders (for example MCADD)
Other disorders (for example congenital hypothyroidism and cystic fibrosis)

For more in-depth information on the disorders click here

How many newborns are screened every year?

Every baby in New Zealand is offered newborn metabolic screening. Over 60,000 newborns are born every year and over 99% have metabolic screening.

How do I find out about the test?

Your Lead Maternity Carer will talk to you about the screening test and give you the opportunity to ask questions. Your Lead Maternity Carer will also give you a brochure containing information about the Newborn Metabolic Screening Programme. Once you agree to the test being done, a few drops of blood are taken from your baby's heel (this is often called the "heel prick test" or "Guthrie test") and collected onto special absorbent paper. The dried blood sample is then sent to the National Testing Centre at Auckland City Hospital for testing.

Who performs the test?

Generally, your Lead Maternity Carer, a hospital midwife or a trained blood taker (phlebotomist) will perform the heel prick test.

Why should my child have newborn metabolic screening?

Newborn metabolic screening is important because a baby with one of these illnesses will appear perfectly healthy and by the time symptoms are visible, irreparable damage can occur, such as mental retardation or sometimes, death.

My baby seems very healthy. Is screening still necessary?

Yes. Most infants with birth defects screened by this programme show no obvious signs of disease immediately after birth. In each of these disorders there is an "invisible" problem in one of the many chemicals which are produced naturally in the baby's body. Without a blood test these problems are hard to find.

Who should have a newborn metabolic screening test?

Health Practitioners strongly recommend screening for all newborns. It is not possible to tell if your baby has one of these disorders just by looking at or examining your baby. These disorders can cause brain damage or death if not found and treated soon after birth. Babies who have these disorders will seem normal, but may get very sick if not found and treated.

When and where should the test be done?

The newborn metabolic screening test should be performed at 48 hours of age or as soon as possible thereafter. The LMC may do the test either in hospital or at home.

Why is the test done at 48 hours or as soon as possible after this?

When the baby is in utero, it is well nourished by the placenta and has all of its needs met by the mother, including getting rid of waste products. If the baby has any problems with its metabolism, these will start showing after 48 hours. This is therefore the best time to test the baby for metabolic disorders.

What are the responsibilities of the Lead Maternity Carer (LMC) in respect to metabolic screening?

The LMC is responsible for:

talking to parents/caregivers about newborn metabolic screening
answering any questions parents have about the programme
gaining parents consent for screening
recording consent/declines
ensuring other health professionals are aware of declines
performing the heel prick test (or ensuring it is performed when consented)
providing any follow-up required by the programme (eg. second samples).

What will the test cost?

The programme is free to all babies born in New Zealand*.

*There are eligibility criteria relating to publicly funded services - see the Ministry of Health website for further information.

How will I receive the results?

The programme will let your Lead Maternity Carer know if there are any problems with your baby's test. Your Lead Maternity Carer also receives a monthly report on the babies under his/her care.

Can I say no to the test?

Yes. New Zealand law says that parents may refuse the test. However, it is strongly recommended that your baby is screened - 99 percent of newborns in NZ are screened. Your Lead Maternity Carer can talk about any concerns or questions you have. Your health professionals (eg, well child provider, general practitioner) will also need to be aware your baby has not been tested.

Can I get the blood test card back?

Yes. You can request your baby's card back after screening is complete. If you would like to request your baby's card, please download and complete the form below and sent to the National Testing Centre. Your Lead Maternity Carer can also access the card return form for you.

Download the form 'Return of newborn metabolic screening samples (guthrie cards) to family'

How much blood is used for screening?

Six small spots of blood are punched out of the card. One of these small spots is used to test for 22 of the disorders using the tandem mass spectrometer. The other 5 spots are used to test for the other 5 disorders. The residual blood is either used to test the blood again if there was a problem with the first result, held in secure storage or returned to the family at their request.

What are the uses of the left over blood?

Any blood that is left over after screening is used for:

Confirmatory testing: if the first result shows an abnormal result, another blood spot will be tested on the same card
Direct benefit of the family/whanau: if a baby has died, at a doctor's request and with parental/caregiver consent, the baby's blood spot card can be tested to identify other disorders
Monitoring the screening programme: for professionally recognised quality assurance programmes
Setting up additional tests: for setting up new equipment for screening
Forensic use: identifying a deceased or missing person or assistance with coronial enquiries.

What happens to the blood card when screening is complete?

When screening is complete, the blood spot card is either returned to the family or held in secure storage. Access to the stored blood spot cards is strictly limited and monitored.

Are repeat samples ever needed?

Occasionally, your Lead Maternity Carer will contact you and request another blood sample to be taken from your baby's heel. This may be because there was not enough blood collected, the result was unclear or the result showed an increased risk for one of the disorders.

Why do most repeat sample results show as a normal result?

Most repeat samples are normal. The reasons relate to the quality of the first sample and the maturity of the baby's metabolism. If the sample has too little or too much blood, is contaminated with other solutions or powders, or has taken too long to reach the laboratory, the result will be inaccurate. If the baby's metabolism is slightly delayed, this may also cause an inconclusive reading. Often therefore, a second sample will be likely to be normal.

What happens if my baby's result is abnormal?

There are a number of reasons for an abnormal result. For example, the blood sample may have been contaminated, not enough blood may have been taken, or the sample may not have reached the lab quickly enough. The sample may also have been "borderline", which means it was not possible to tell whether or not there was a problem. In these cases, your Lead Maternity Carer may talk to you about taking another sample.

The result may also have been abnormal because the result shows one of the disorders tested for may have been found. The laboratory will contact your LMC if this is the case. Further diagnostic testing will be necessary to confirm this. Other practitioners such as paediatricians will also be involved. Many of the effects of disorders can be reduced - either by a special diet or medicine - but treatment is best if started early. Babies with a condition cannot be "cured" but they can be treated, each in their own special way. Your Lead Maternity Carer and other health practitioners will talk with you about the best treatment for your baby.

What if English is not my first language - how can I get the information explained to me?

Your Lead Maternity Carer should provide you with the resources that you need to make decisions regarding your pregnancy and newborn. Please talk to your Lead Maternity Carer if you require translation or other services.