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Blood Collection

The following are frequently asked questions about blood collection, including the blood spot card.

Blood spot cards are best collected prior to discharge and between 24 and 48 hours of age (pre-term and term babies). If collection is not completed during this time, collection should be done no later than seven days of age in order to ensure early detection of these treatable disorders. If a baby is discharged from hospital prior to 24 hours of age, an initial card is collected before discharge. A second card is collected by 2 weeks (14 days) of age.


No, as long as the specimen was collected after 24 hours, the screen will detect the conditions regardless of whether the baby has started feeding (breast/bottle) or is on Total Parenteral Nutrition (TPN) or intravenous fluids.


Blood transfusions are known to affect the results of hemoglobinopathy and galactosemia screens and may affect other screens as well (Reed, 2000; Korson, 1990).

If a blood transfusion is anticipated, whenever possible, collect a blood spot card prior to the transfusion regardless of the baby’s age.

If the baby is less than 24 hours old when the card is collected, the NBS Laboratory will request, through the baby’s physician/midwife, that a repeat card be collected by two weeks (14 days) of age.

If a blood spot card is not collected prior to the transfusion, collect at 24 – 48 hours of age. The NBS Laboratory will request, through the baby’s physician/ midwife, that two repeat cards be collected, one at three weeks (21 days) and one at four months (120 days) after the date of the transfusion.


Very low birth weight babies who have congenital hypothyroidism (CH) may have a delayed rise in thyroid stimulating hormone (TSH). The first screen (done at 24 – 48 hours) may miss the identification of CH in some of these babies (Tylek-Lemariska D, 2005; Grufeiro-Papendieck L., 2005).

For this reason, the NBS Laboratory will request, through the baby’s physician/midwife, that a repeat card be collected at day 21 or on discharge from hospital, whichever is sooner.

For babies where blood is difficult to draw (e.g., premature infants), it is acceptable to fill 2 out of the available spots on the card.


No, the baby can go to any maternity hospital laboratory in BC.


The first blood screen will identify over 80% of disorders and will help to prevent life threatening events such as severe or potentially fatal bacterial infections in babies with galactosemia or significant metabolic crises in babies with medium-chain acyl-CoA dehydrogenase deficiency (MCAD), very-long chain acylCoA dehydrogenase deficiency (VLCAD) or maple syrup urine disease (MSUD).

The second screen optimizes detection of phenylketonuria (PKU), cystic fibrosis (CF) and homocystinuria (Hcy) which are time sensitive and cannot be reliably detected until 24 hours or more after birth.


A pilot study at BC Women’s Hospital to trial deferral of testing revealed that up to eight percent of parents did not return with their baby to the hospital for blood collection. Many parents find it difficult to return to the lab shortly after discharge with their baby, despite their best intentions. If a second sample is never collected, at least the baby will have received most of the benefits of screening.


Provide the parent(s)/guardian information about the rationale for collecting blood prior to discharge and the risks if newborn screening is not done.

If they still decline collection of the card prior to discharge from hospital, have them sign the “Informed Deferral: Newborn Screening” Form (see Appendix 4 of this guideline) and make arrangements for them to have a blood card collected after discharge.

Exceptions to collection of two blood spot cards may apply if a health authority/hospital has a standard process in place to follow-up after discharge to ensure a blood spot card is collected or if the baby is under the care of a registered midwife. See Appendix 5 in this guideline for more information about setting up a deferral process.

Note: If an initial blood spot card is collected, the NBS Laboratory will track that a follow-up card(s) is collected (if required). If an initial card is never collected, the NBS Laboratory is unable to identify or track babies for screening.


Ask the parent(s)/guardian to read the brochure “A simple blood test could save your baby’s life” (available in multiple languages on this website).

Discuss the benefits of newborn screening and answer questions/address concerns. Often, their reservations are due to lack of understanding and can be easily resolved.

If they still decline screening, have them sign the Informed Refusal: Newborn Screening Form.

Place a copy of the signed form in the baby’s health record and send a copy to the baby’s physician/midwife.


Contact the Newborn Screening Laboratory:

Phone: 604-875-2148


Note: Plan ahead and allow enough time for the cards to reach you by regular mail, so that you do not run out of cards.


SOURCE: Blood Collection ( )
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