Newborn blood spot screening

In the UK all babies are offered screening for 9 conditions, as recommended by the UK National Screening Committee (NSC) (UK Newborn Screening Programme 2012). 

NOTE: We review our guidelines regularly and this guideline is now past its review date. The content of the guideline below may not reflect the most recent evidence based practice. Please use with caution.

These include:

  • Phenylketonuria (PKU)
  • Congenital hypothyroidism (CHT)
  • Sickle cell disease (SCD)
  • Cystic fibrosis (CF)
  • Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
  • Homocystinuria (HCU)
  • Maple syrup urine disease (MSUD)
  • Glutaric Acidemia Type 1 (GA1)
  • Isovaleric Acidemia (IVA).

The aim of the newborn blood spot screening is to: 

  • Achieve early detection, referral and treatment of babies thought to be affected by the above conditions.

The aim of this guideline is to:

  • Ensure a consistent approach to newborn blood spot sampling within Great Ormond Street Hospital (GOSH).
  • Support staff in obtaining good quality samples, reducing the need for repeats.

Consent

It is important to offer parents an informed choice about screening for their baby.

Explain fully to parents why the blood spot screening test needs to be taken and give a copy of the booklet Screening tests for you and your baby; babies in special care units. This booklet is available in English and 10 other languages.

  • At least 24 hours pre-test (Rationale 1). 
  • Verbal consent is adequate (written consent is not required). Parents' decision should be documented in the child’s medical notes.

If the parents decline screening:

  • Record 'decline’ and reason for the decline (if stated) in the baby’s medical notes and nursing care plan (Rationale 2). 
  • Complete a blood spot screening card including all relevant patient details. Mark the card as ‘Decline’ in the comments box and send to the Camelia Botnar newborn screening laboratory. 
  • Inform GP and health visitor (HV) of the conditions for which the parents have declined screening (Rationale 3).
  • Inform parents who to contact if they change their mind or would like further information (Rationale 4).

When to screen

See Appendix 1: example screening calendars.

Days five to eight

  • All babies whose parents have consented to screening must have a sample taken between days five to eight (ideally on day five) regardless of medical condition, feeding or prematurity (Rationale 5).
  • All four spots should be filled on a new screening card.
  • For the purpose of screening date of birth is day zero. 

Babies that are admitted to hospital may require additional screening.

Admitted to hospital at less than five days of age

  • Babies admitted to hospital at less than five days of age should have a single spot sample taken on admission (Rationale 6).
  • Mark the card ‘pre transfusion’ in the comments box (Rationale 7).
  • Babies admitted to GOSH from neonatal units will often have a pre transfusion sample with them. In this case another pre transfusion sample is not required. 
  • Keep the sample with the baby and send with routine day five sample. Note: a separate card must be used for each sample (pre transfusion, day five etc).
  • If a pre transfusion sample does not accompany the baby on admission and you are sure the baby has not received a transfusion of red blood cells take a single spot sample as directed above.
  • If a baby is transferred to another ward or hospital before the day five sample has been taken, ensure the ‘pre-transfusion’ blood spot card accompanies the baby.

Transfusion

  • For the purpose of newborn screening a transfusion is classed as: an exchange transfusion, red cells, platelets and fresh frozen plasma (Rationale 8).
  • If a baby receives a transfusion of any of the above prior to the day five sample being obtained, it will be three clear days before a valid screening sample will be able to be obtained (Rationale 9).
  • All babies must have a sample taken by day eight regardless of transfusions (Rationale 5).
  • If a baby requires frequent transfusions and there is not three clear days between days five to eight a sample must be taken by day eight and a repeat will be required the next time the baby is three days clear post transfusion (Rationale 10).
  • Due to the fact that there is no dedicated place on the screening card for recording the time of transfusion or time of sample, the fourth day post transfusion is usually given as a guide as to when to screen post transfusion (allowing three days). 
  • If the time the last transfusion ended and the time the sample was taken is documented in the comments box of the screening card, the sample may be taken a full 72 hours after the last transfusion instead of waiting until the fourth day. This may be useful in patients requiring frequent on-going transfusions (Rationale 11).
  • The date of last transfusion and what was transfused must always be documented on the screening card. (Rationale 12).

Less than 32 weeks

  • Babies born at less than 32 weeks (less than or equal to 31 weeks and six days) gestation require an additional two spot sample at 28 days or discharge home, whichever is sooner (Rationale 13).
  • Mark the card ‘CHT preterm’ in the comments box (Rationale 14).

Repeat samples

Unavoidable repeat samples may be required from a few babies due to borderline thyroid stimulating hormone (TSH) results, inconclusive CF screening or having received a blood transfusion (Rationale 15).  

  • A seven-day interval between samples is recommended for borderline TSH results. Take a four blood spot sample and mark the card 'CHT borderline' (Rationale 16). This information should be included on the repeat request letter sent by the labs.
  • Ensure that the 'repeat sample' box is ticked on the blood spot card.

Avoidable repeat samples may also be requested by the labs due to any of the following:

Ensuring completeness of coverage of newborn screening

Newborn screening is offered to all infants up to one year of age (Rationale 22) (blood spot screening for CF can only be carried out up until 56 days of age (Rationale 23)).

Ensure all infants less than one year of age who are admitted to GOSH have documented evidence of newborn screening (Rationale 24). 

If conclusive documentation cannot be found in transfer documentation or Personal Child Health Record (PCHR or `Red book’).

  • Contact Camelia Botnar neonatal screening laboratory on ext 8383 to verify date of blood spot screening for babies born in the north Thames region or contact the neonatal nurse advisors bleep 0256.

If you are still unable to find conclusive documentation:

  • Discuss with parents and obtain consent for screening as discussed above.
  • Take a sample and send completed card to the Camelia Botnar Screening Laboratory.
  • Document in PCHR and medical notes.

Patients from outside the UK

Visiting patients from outside of the UK are not currently able to be offered screening. The only exception to this rule is patients from Malta. Babies from Malta may be offered screening in the same way as an NHS patient. They will not have an NHS number so it must be stated clearly on the card that the patient is from Malta.

Entering the details on the blood spot card

  • Check expiry date on the front of the card (Rationale 25).
  • Complete the blood spot card at the time of sampling and check with the parent (if present) that all details on the card are correct and make any necessary changes. 
  • Legibly complete all fields on the card (Rationale 26).
  • When completing the card care must be taken to avoid contamination (Rationale 27).
  • Refer to Newborn blood spot screening card information quick-reference guide to ensure all require information is recorded (Rationale 26).

The Trust has developed a quick-reference guide, Newborn blood spot screening card information, to help staff ensure the correct information is recorded on the card (Appendix 2). Please refer to this when filling in the cards as incorrect information can delay screening resulting in unnecessary repeats and potentially a delay in diagnosis and treatment.

Zero-tolerance to missing information: If any of this information is missing from the card the sample will not be processed and a repeat will be requested (Rationale 28):

  • NHS number (or CHI number for patients from Scotland and Northern Ireland).
  • Date of birth.
  • Date of sample.

Record any of the following in the ‘comments’ box on the card (Rationale 29): 

  • Baby’s known medical condition. 
  • Relevant family history eg CF, PKU, etc.
  • Reason for sample if not taken on days five to eight (eg pre transfusion, repeat post blood transfusion, preterm CHT)

Collecting the blood spot sample

It is important that an adequate sample is taken to prevent the need for unnecessary repeats. 

In order to take the newborn blood spot sample you will need:

  • The UK NSC’s booklet Screening tests for you and your baby. 
  • Baby’s NHS number. 
  • Birth history form (Appendix 3).
  • Blood spot card and glassine envelope (spare cards can be obtained from the Camelia Botnar newborn screening laboratory).
  • Water for cleansing.
  • Non-sterile protective gloves and plastic apron.
  • Automated incision device for use on newborns. 
  • Sharps box.
  • Cotton wool/gauze or spot plaster.

Comfort measures

  • Ensure the baby is in a secure position for taking the sample (Rationale 30).
  • Ensure comfort measures are used (Rationale 31). For example, breastfeeding, non-nutritive sucking (eg a 'dummy' or pacifier) or a sucrose solution (Rationale 32).

Procedure

The sample can be obtained from a capillary heel prick or central arterial or venous line if present providing the line is cleared of infusate and not contaminated with EDTA (ethylenediaminetetraacetic acid) 

If taking a capillary heel prick sample (see appendix 5 for example blood spots):

  • Wash hands and apply gloves and apron (Rationale 33).
  • Clean the heel by washing thoroughly with plain water and the heel should be completely dry before taking the sample (Rationale 34).
  • Do not use alcohol or alcohol wipes (Rationale 35).
  • Additional pre-warming of the foot is not required (Rationale 36).
  • Perform the test using an automated incision device designed for use on newborns. Manual lancets must not be used (Rationale 37). 
  • For full-term and pre-term infants, the external and internal limits of the calcaneus are the preferred puncture site (Rationale 38)(Appendix 4). Skin puncture must be no deeper than 2.0mm (Rationale 39).
  • For infants who have had repeated heel punctures, the areas marked in diagram B (Appendix 4) may also be used. When using the whole plantar surface, an automated incision device with a penetrative depth of no more than 1.0mm is recommended (Rationale 39).
  • Avoid posterior curvature of the heel (Rationale 40).
  • Allow the heel to hang down to assist blood flow (Rationale 41).
  • Before activation place the automated incision device against the heel in accordance with manufacturer's instruction (Rationale 42).
  • The aim is to fill each circle on the newborn bloodspot card, using a single drop of blood (see Appendix 5).
  • Wait for the blood to flow. Allow one spot of blood to drop onto each of the circles of the card. Do not allow the heel to make contact with the card (Rationale 43).
  • Do not squeeze the foot in an attempt to increase blood flow (Rationale 44).
  • Allow the blood to fill the circle by natural flow, and seep through from front to back (Rationale 45).
  • Fill each of the four circles completely and do not layer the blood (Rationale 46).
  • Do not compress the blood spot in order to ensure the blood has soaked through to the reverse of the card (Rationale 47).
  • If the blood flow ceases: 
    • The congealed blood should be wiped away firmly with cotton wool or gauze (Rationale 48).
    • Gently ‘massage’ the foot, avoid squeezing, and drop the blood onto the card (Rationale 49).
    • If the baby is not bleeding, a second puncture is necessary. The second puncture should be performed on a different part of the same foot or on the other foot, as marked by the shaded areas in diagrams A and B (Appendix 4)(Rationale 50).
    • When the sample collection is complete, wipe excess blood from the heel and apply gentle pressure to the wound with cotton wool or gauze (Rationale 51).
    • Apply a spot plaster if required and remove in a few hours.

After taking the blood sample

  • Allow blood spots to air dry away from direct sunlight or heat before placing in the glassine envelope (Rationale 52).
  • Despatch the blood spot card to the Camelia Botnar newborn screening laboratory via the specimen chute (051/011) or the porters on the same day (Rationale 53).
  • Record the date of sample on the birth history form in the front of the medical notes or  Carevue as applicable (if moving from a Carevue area to a Ward please ensure screening status is recorded on the birth history form (Rationale 54).
  • Record that sample has been taken in the personal child health record (PCHR: red book) if available.
  • Record and notify screening status on transfer and discharge documentation (Rationale 55).
  • Inform parents of any outstanding screening tests and record this in the PCHR. Advise parents which healthcare professional will be responsible for completing the blood spot screening for their baby and approximately when it will occur (Rationale 55).
  • Inform parents that they will receive the results within six to eight weeks. If the baby screens positive for a condition the parents will be contacted sooner.
  • Inform parents how they will receive the results (if known) eg by medical staff if in hospital or via the health visitor if at home.
  • Advise parents to contact the health visitor if results are not received within six to eight weeks (Rationale 56).

Failsafe processes

Newborn screening is audited internally and externally. Data from the internal audit can be found on the GOSH intranet.

The audit questions include:

  • Number of babies screened between day five to eight.
  • Number of avoidable repeats and reasons for the repeats.

We also have access to the Northgate failsafe system that allows us to check the screening status of all babies admitted to GOSH from England and Wales. If you are interested in gaining access to this system please contact Marie-Anne Kelly (Neonatal CNS). 

Teaching

Additional teaching videos and quick reference guidelines are available on the Newborn Blood Spot screening website

Rationale

Rationale 1: To enable parents to make informed decisions and maintain the high level of uptake of screening.
Rationale 2: To monitor rates of consents/declines and effectively communicate parents’ requests to the laboratory and child health records department.
Rationale 3: To ensure the GP and health visitor does not assume testing has been completed.
Rationale 4: To ensure parents know how to have their baby screened if they wish.
Rationale 5: To enable timely detection of abnormal results and initiation of appropriate treatment.
Rationale 6: In case they require a blood transfusion as the screening test for SCD cannot be done on samples from babies who have received a blood transfusion.
Rationale 7: To ensure the lab know the reason for the sample.
Rationale 8: Any blood product that will affect the circulating concentration of the measured metabolite.
Rationale 9: Transfusions may affect the concentration of measured metabolites for a period of time.
Rationale 10: To ensure no patient misses screening.
Rationale 11: To enable a valid screen to be completed as early as possible after day five.
Rationale 12: To enable accurate interpretation of screening results.
Rationale 13: As prematurity can mask congenital hypothyroidism (CHT).
Rationale 14: To ensure the lab know the reason for the sample.
Rationale 15: To ensure screened babies receive a valid result.
Rationale 16: An interval of one week is required to detect any meaningful change in TSH levels.
Rationale 17: Unable to confirm baby’s age at sample.
Rationale 18: Unique identification number for each baby.
Rationale 19: Not enough blood to analyse to ensure accurate result.
Rationale 20: May lead to an invalid result.
Rationale 21: May delay treatment.
Rationale 22: To identify any affected baby and ensure treatment commences as soon as possible.
Rationale 23: As it is no longer accurate after this age.
Rationale 24: To identify any affected baby and ensure treatment commences as soon as possible.
Rationale 25: The laboratory will be unable to process the sample if the card is out of date, a repeat sample will be required and possible delay in treatment.
Rationale 26: If the laboratory is unable to read the information on the card or the card is not fully/accurately completed the sample will not be processed and a repeat will be requested.
Rationale 27: Contamination of the sample may affect the test results.
Rational 28: Date of birth and date of sample needed to confirm baby’s age at sample, NHS number is the unique identification number for each baby.
Rationale 29: To assist the newborn screening laboratory with linking antenatal and newborn screening results, and to ensure the results are interpreted correctly.
Rational 30: To ensure safety of the baby and make it easier for the professional to take the sample.
Rationale 31: To make it easier for the baby to cope with the procedure.
Rationale 32: To reduce the pain/discomfort of the procedure.
Rationale 33: In accordance with the infection control policy.
Rationale 34: Contamination of the sample may affect the test results.
Rationale 35: The use of alcohol for skin preparation in neonates and premature babies can cause burns and blisters.
Rationale 36: There is no evidence that warming aids blood flow (Glenesk et al 2006).
Rationale 37: Newborn automated incision devices reduce pain and bruising, allow users to obtain the sample more quickly and reduce the risk of accidental injury from manual lancets (Shepherd et al 2006).
Rationale 38: The skin to calcaneus depth is greater in these areas.
Rationale 39:  To minimise the risk of calcaneal puncture that may lead to calcaneal osteomyelitis (Arena et al 2005).
Rationale 40: This reduces the soft tissue damage and pain from repeated heel puncture in the same area.
Rationale 41: Assists adequate blood flow.
Rationale 42: To ensure the correct depth of incision is achieved.
Rationale 43: To prevent contamination.
Rationale 44: This may cause pain and bruising to the baby.
Rationale 45: This gives the optimum amount of blood for the laboratory to utilise.
Rationale 46: Layering of the blood is unacceptable for testing because too much blood can cause erroneous results (see diagram, Appendix 5).
Rationale 47: Applying pressure reduces the density of the sample and can lead to a `suspected’ result being missed.
Rationale 48: To disturb the clot and encourage blood flow.
Rationale 49: To reduce the amount of pain and bruising caused by the procedure.
Rationale 50: The original site is avoided to prevent the sample from containing excessive tissue fluid and to reduce pain.
Rationale 51: To prevent excessive bleeding and bruising and to protect the wound.
Rationale 52: Wet samples can stick to the envelope and a repeat sample will be required.
Rationale 53: Ensures that the card is received in the laboratory within three working days of the sample being taken. Timeliness of despatch enables early analysis and subsequent treatment.
Rationale 54: For internal audit purposes and to comply with NMC record keeping guidelines (NMC 2010).
Rationale 55: To ensure the screening status is known and to transfer responsibility for obtaining any outstanding tests.
Rationale 56: To ensure all parents receive results of screening.

References

Arena, J., Emparanza, JI., Nogués, A., Burls, A. (2005) Skin to calcaneus distance in the neonate. Arch Dis Child Fetal Neonatal Ed, 90(4): p. F328-F331.

Glenesk, A., A. Shepherd, and C. Niven (2006) Blood spot testing: comparing techniques and automated devices. British Journal of Midwifery. 14 (1). 

Nursing and Midwifery Council (2006) Record Keeping: Guidance for Nurses and Midwives. London [last accessed 13.12.2016].

Shepherd, A.J., et al. (2006) A Scottish study of heel-prick blood sampling in newborn babies. Midwifery 22(2): P.158-168

UK Newborn Screening Programme Centre (2016) Guidelines for newborn blood spot sampling [ast accessed 13.12.2016].

UK Newborn screening programme website (2016) [last accessed 13.12.2016].

Appendices

Appendix 1: example screening calendars
Appendix 2: screening card information
Appendix 3: example birth history form (Eproc code WWG871)
Appendix 4: puncture sites
Appendix 5: blood spots 
Appendix 6: 

Document control information

Lead Author(s)

Marie-Anne Kelly, Neonatal Clinical Nurse Specialist

Document owner(s)

Marie-Anne Kelly, Neonatal Clinical Nurse Specialist

Approved by

Guideline Approval Group

Reviewing and Versioning

Date approved: 
21 October 2012
Review schedule: 
Three years
Next review: 
21 October 2017
Document version: 
2.1
Previous version: 
2.0