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 2016). 

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.


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.

Consent for research contact

  • Parents should be asked if they wish to be contacted about research linked to the screening programme (Rationale 2) 
  • If parents do not wish to be contacted about research ‘No Research contact’ should be recorded clearly on the blood spot card (Rationale 3).
  • Ensure parents are aware that patient identifiable information may be stored by the NHS Sickle Cell and Thalassaemia screening programme (Rationale 4) Link 3
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 5). 
  • 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 6).
  • Inform parents who to contact if they change their mind or would like further information (Rationale 7).

When to screen

See Appendix 1: example screening calendars.

Day 5 (5-8 if transfused)

  • All babies whose parents have consented to screening must have a sample taken on day 5 (or between day 5-8 if transfused) regardless of medical condition, transfusion, feeding or prematurity (Rationale 8).
  • A sample must be sent for every baby by day 8 at the latest regardless of transfusion.
  • 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 9).
  • Mark the card ‘pre transfusion’ in the comments box (Rationale 10).
  • 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.


  • For the purpose of newborn screening a transfusion is classed as: an exchange transfusion, red cells, platelets and fresh frozen plasma (Rationale 11).
  • If a baby receives a transfusion of any of the above prior to the day five sample being taken, it will be three clear days before a valid screening sample will be able to be obtained (Rationale 12).
  • All babies must have a sample taken and sent by day eight regardless of transfusions (Rationale 13).
  • 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 clear days post transfusion (Rationale 14) See screening calendars.
  • 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 clear days). 
  • If the time the last transfusion ended and the time the sample was taken is clearly 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 only recommended for patients requiring frequent on-going transfusions (Rationale 14).
  • The date of last transfusion and what was transfused must always be documented on the screening card. (Rationale 15).

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 16).
  • Mark the card ‘CHT preterm’ in the comments box (Rationale 17).
  • If the baby has been transfused you will need to wait until the baby is 3 clear days post transfusion before taking this sample (Rationale 12, 15)

Repeat samples

There are 2 types of repeat request:
  1. Avoidable repeats: where we could have done something differently
  2. Unavoidable repeats: where there was nothing we could do to prevent it
We are only measured on our Avoidable repeat rate.
Unavoidable repeat samples may be required from a few babies due to:
  • Borderline thyroid stimulating hormone (TSH) results
  • Inconclusive CF screening results
  • The baby having received a blood transfusion within 3 days of the sample being taken (Rationale 11). 
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 18). 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:
  • incomplete data on the card, eg no date of sample (Rationale 19)
  • no NHS number (Rationale 20) 
  • insufficient blood on the card (Rationale 21)
  • layering of blood (Rationale 22) 
  • delay in laboratory receiving the sample (Rationale 22) 
  • taken before five days of age (Rationale 23) 
  • repeat samples taken at the wrong time (Rationale 22) 
  • contamination of the sample card (Rationale 24) 

Ensuring completeness of coverage of newborn screening

Newborn screening is offered to all infants up to one year of age (Rationale 25) (blood spot screening for CF can only be carried out up until 56 days of age (Rationale 26).
Ensure all infants less than one year of age who are admitted to GOSH have documented evidence of newborn screening (Rationale 25). 
If conclusive documentation cannot be found in transfer documentation or Personal Child Health Record (PCHR or `Red book’).
  • Ask parents if they have a letter showing the screening results
  • 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 advisor.
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

Babies from Malta

Babies from Malta may be offered screening in the same way as an NHS patient. They are the only patient that will not have an NHS number so ‘patient from Malta’ must be written clearly in the comments box of the screening card.

Babies born to UK forces personnel stationed overseas

Babies born to UK personnel station overseas are entitled to NHS treatment and should have an NHS number generated by their midwife shortly after birth. Check the NHS spine if the NHS number isn’t in the transfer notes and if there is a delay in generating an NHS number child health can help. 

All other patients from outside the UK

Babies born outside the UK are not eligible for screening under the UK Newborn blood spot screening programme. The medical team responsible for the baby should check what screening the baby has already received and then make the decision to offer to test the baby for the above conditions.

Entering the details on the blood spot card

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: It can help to fill in these 3 bits of information first. If any of this information is missing from the card the sample will not be processed and a repeat will be requested (Rationale 27):
  • NHS number (or CHI number for patients from Scotland and HSCN number for patients from Northern Ireland).
  • Date of birth.
  • Date of sample.
After filling in the zero tolerance info ensure that the rest of the card is completed:
  • Check expiry date on the front of the card (Rationale 22).
  • 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 27).
  • When completing the card care must be taken to avoid contamination (Rationale 24).
  • Refer to Newborn blood spot screening card information quick-reference guide to ensure all require information is recorded (Rationale 22).
Record any of the following in the ‘comments’ box on the card (Rationale 28, 29): 
  • Baby’s known medical condition. 
  • Relevant family history eg CF, PKU, etc.
  • Reason for sample if not taken on days five to eight (e.g. pre transfusion, repeat post blood transfusion, preterm CHT)
Maternity and Neonatal units use pre-printed barcoded labels that include some but not all of the information required on the card. We cannot currently print our own but if these accompany the patient you can use them to help you fill in the samples you take but you must:
  • Check the information is correct and complete
  • Add a sticker to each layer of paper
  • Fill in any info that is not on card e.g. date of sample

Collecting the blood spot sample

It is important that an adequate sample is taken to prevent the need for unnecessary repeats. 
Appendix 3: Blood spot examples
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 4).
  • Blood spot card and glassine envelope (spare cards can be obtained from the Camelia Botnar newborn screening laboratory).
  • Water for cleansing (the water should not be heated and the foot should not be submerged (Rationale 30).
  • 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 31).
  • Ensure comfort measures are used (Rationale 32). For example, breastfeeding, non-nutritive sucking (eg a 'dummy' or pacifier) or a sucrose solution (Rationale 33).


Venepuncture or venous / arterial sampling from an existing line can be used to collect the blood spot sample onto the card. This is providing the sample is not contaminated with EDTA/heparin and the line is cleared of infusate. (Rationale 34)
Do not use heparinised syringes or capillary tubes (Rationale 35) 
If taking a capillary heel prick sample (see appendix 3 for example blood spots):
  • Wash hands and apply gloves and apron (Rationale 36).
  • Clean the heel by washing thoroughly with plain water (the water should not be heated and the heel should not be submerged (Rationale 30) the heel should be completely dry before taking the sample (Rationale 37).
  • Do not use alcohol or alcohol wipes (Rationale 37).
  • Additional pre-warming of the foot is not required (Rationale 38)
  • Perform the test using an automated incision device designed for use on newborns. Manual lancets must not be used (Rationale 39). 
  • For full-term and pre-term infants, the external and internal limits of the calcaneus are the preferred puncture site (Rationale 40)(Appendix 5). Skin puncture must be no deeper than 2.0mm (Rationale 41).
  • For infants who have had repeated heel punctures, the areas marked in diagram B (Appendix 5) 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 41, 42).
  • Avoid posterior curvature of the heel (Rationale 41).
  • Allow the heel to hang down to assist blood flow (Rationale 43).
  • Before activation place the automated incision device against the heel in accordance with manufacturer's instruction (Rationale 44).
  • The aim is to fill each circle on the newborn bloodspot card, using a single drop of blood (see Appendix 3).
  • 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 45).
  • Do not squeeze the foot in an attempt to increase blood flow (Rationale 46).
  • Allow the blood to fill the circle by natural flow, and seep through from front to back (Rationale 47).
  • Fill each of the four circles completely and do not layer the blood (Rationale 48)
  • Do not compress the blood spot in order to ensure the blood has soaked through to the reverse of the card (Rationale 49).
  • If the blood flow ceases: 
    • The congealed blood should be wiped away firmly with cotton wool or gauze (Rationale 50).
    • Gently ‘massage’ the foot, avoid squeezing, and drop the blood onto the card (Rationale 51).
    • 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 5)(Rationale 52).
    • 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 53).
    • 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 54).
  • 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 55).
  • 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 56).
  • Record that sample has been taken in the personal child health record (PCHR: red book) if available, if parents were not given a red book ante-natalay the neonatal CNS keeps a small stock ext 6355.
  • Record and notify screening status on transfer and discharge documentation (Rationale 57)
  • 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 58)
  • 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) e.g. 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 59).


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.

Failsafe processes

We 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). 

Email prompts

The trust has set up automated email prompts that are sent out daily to any ward area to notify them that they either have a neonate on the ward who are either within the 5 to 8 day window in which their new born blood spot screening or are less than 8 days old and there is no NHS number recorded on PiMS (patients from outside the UK are excluded from email prompts)
Please note this email is only a prompt to highlight patients within the screening window and with missing data on PiMS and does not indicate if a screening test has been performed or if any repeats are needed. There should be a process for recording and checking this information in your ward area.
The prompts are sent to designated individuals usually including the ward sister, matron, all of the in charge nurses and the ward admin staff and their managers. Some wards also include practice educators so they are made aware that staff may need support. If you would like to add or remove anyone from the list please contact the Neonatal CNS ext 6355.
Missing NHS numbers can be located using the NHS Spine – See the Admission SOP for updating information on PiMS for more information.


Additional teaching videos and quick reference guidelines as well as links to the national screening guidelines are available on the Neonates page of the intranet. Enter ‘Neonates’ or ‘Neonate’ into the search on the home page and it is the first option.
There is a newborn blood spot screening module available on GOLD.


Rationale 1: To enable parents to make informed decisions and maintain the high level of uptake of screening.

Rationale 2: Stored blood spot cards can be used to monitor and improve the newborn screening programme

Rationale 3: In accordance with the Code of Practice for the Retention and Storage of Residual Spots

Rationale 4: This is used to monitor and improve screening for sickle cell and thalassaemia.

Rationale 5: To monitor rates of consents/declines and effectively communicate parents’ requests to the laboratory and child health records department.
Rationale 6: To ensure the GP and health visitor does not assume testing has been completed.
Rationale 7: To ensure parents know how to have their baby screened if they wish.
Rationale 8: To enable timely detection of abnormal results and initiation of appropriate treatment.
Rationale 9: 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 10: To ensure the lab know the reason for the sample.
Rationale 11: Any blood product that will affect the circulating concentration of the measured metabolite.
Rationale 12: Transfusions may affect the concentration of measured metabolites for a period of time.
Rationale 13: To ensure no patient misses screening.
Rationale 14: To enable a valid screen to be completed as early as possible after day five.
Rationale 15: To enable accurate interpretation of screening results.
Rationale 16: As prematurity can mask congenital hypothyroidism (CHT).
Rationale 17: To ensure the lab know the reason for the sample.
Rationale 18: An interval of one week is required to detect any meaningful change in TSH levels.
Rationale 19: Unable to confirm baby’s age at sample.
Rationale 20: Unique identification number for each baby.
Rationale 21: Not enough blood to analyse to ensure accurate result.
Rationale 22: Risk of inaccurate result
Rationale 23: Risk of inaccurate result
Rationale 24: May result in a false positive for CHT.

Rationale 25: To identify any affected baby and ensure treatment commences as soon as possible.
Rationale 26: As it is no longer accurate after this age.

Rationale 27: Without all the zero tolerance information the labs are not able to identify the baby.

Rationale 28: To assist the newborn screening laboratory with linking antenatal and newborn screening results.

Rationale 29: To ensure the result is interpreted correctly

Rationale 30: The NHS Newborn Blood Spot Screening Programme has received reports of babies being scalded/burned during warming of the heel in preparation for blood spot sampling

Rational 31: To ensure safety of the baby and make it easier for the professional to take the sample.
Rationale 32: To make it easier for the baby to cope with the procedure.
Rationale 33: To reduce the pain/discomfort of the procedure.
Rationale 34: Contamination with EDTA can affect newborn screening results.

Rationale 35: Lithium heparin can affect DNA testing. This could affect the protocol used to detect CF and SCD.

Rationale 36: In accordance with the infection prevention and control policy.
Rationale 37: The use of alcohol for skin preparation in neonates and premature babies can cause burns and blisters.
Rationale 38: There is no evidence that warming aids blood flow (Glenesk et al 2006).
Rationale 39: 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 40: The skin to calcaneus depth is greater in these areas.
Rationale 41:  To minimise the risk of calcaneal puncture that may lead to calcaneal osteomyelitis (Arena et al 2005).
Rationale 42: This reduces the soft tissue damage and pain from repeated heel puncture in the same area.
Rationale 43: Assists adequate blood flow.
Rationale 44: To ensure the correct depth of incision is achieved.

Rationale 45: This can prevent blood from soaking through to the back of the card
Rationale 46: This may cause pain and bruising to the baby.

Rationale 47: This gives the optimum amount of blood for the laboratory to utilise.

Rationale 48: Risk of false-negative result

Rationale 49: Applying pressure reduces the density of the sample and can lead to a `suspected’ result being missed.
Rationale 50: To disturb the clot and encourage blood flow.

Rationale 51: To reduce the amount of pain and bruising caused by the procedure.
Rationale 52: The original site is avoided to prevent the sample from containing excessive tissue fluid and to reduce pain.
Rationale 53: To prevent excessive bleeding and bruising and to protect the wound.

Rationale 54: Wet samples can stick to the envelope and a repeat sample will be required.

Rationale 55: 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 56: For internal audit purposes and to comply with record keeping best practice

Rationale 57: To ensure the screening status is known and to transfer responsibility for obtaining any outstanding tests.

Rationale 58: To ensure parents are fully informed.
Rationale 59: To ensure all parents receive results of screening.


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). 

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].

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: 
01 December 2017
Review schedule: 
Three years
Next review: 
01 December 2020
Document version: 
Previous version: