Polycythaemic Newborn - Management of the

Publication: 26/08/2010  
Next review: 27/09/2024  
Clinical Guideline
ID: 2160 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2021  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Management of the Polycythaemic Newborn


Neonatal Polycythaemia affects 2-5% of newborns. It is defined as a haematocrit/Haemoglobin concentration > two standard deviation above the normal value for gestational and postnatal age (1). A term baby is considered to be polycythaemia if haematocrit from a peripheral venous sample is above >65% or Haemoglobin >22 g/dL (2-5).

  • The haematocrit typically peaks at 4-6 hours after birth and the declines over the next 12-18 hours so that by 24 hours of age it is equivalent to that at birth.7 the postnatal age at which newborns are screened is very relevant as the incidence may increase up to 20% when screened at two hours whereas may be as low as 2% when screened at 12-18 hours postnatally. (6)
  • Capillary samples have been proven to over-estimate PCV and the gold standard for diagnosis is arterial or umbilical venous sample. In the clinical setting a free flowing sample from a large vein is sufficient for diagnostic criteria (7).

Most of the clinical significance of polycythaemia is related to associated increase in blood viscosity (3 - Medscape). The relationship between haematocrit and viscosity is linear below haematocrit levels of 60% whereas progressive increases over 65% show a logarithmic relationship (8,9). This means even a small increase in haematocrit after that leads to exponential increase in the viscosity. Although several factors determine blood viscosity like blood pH, plasma protein concentration, Platelet and WBC volume as well as endothelial factors. In the newborn the principle determinant of blood viscosity is the haematocrit.(7) Hyperviscosity occurs in about 47% of infants with polycythaemia(10).

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Causes of Polycythaemia:

(Table 1)

Erythrocyte transfusion (passive)

Very delayed clamping of the umbilical cord (e.g., >2-3 minutes after birth)

Uncontrolled or precipitous delivery

Intrapartum hypoxia

Twin-to-twin transfusion (10 to 15 percent of monochorionic twins)

Maternal-fetal transfusion (rare)

Increased intrauterine erythropoiesis (active)

Placental insufficiency


Chronic or recurrent placental abruption

Other hypertensive disorders

Other Vascular disorders

Maternal hypoxemia due to cardiac or pulmonary disorders

Cardiac or pulmonary disorders



High altitude


Infant risk factors

Large for gestational age

Small for gestational age

Maternal Diabetes Mellitus

Beckwith-Wiedman Syndrome

Endocrine abnormalities (Cong Adrenal Hyperplasia, hypothyroidism, hyperthyroidism)

Chromosomal abnormalities (21,18 and 13)

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Clinical Features:

Most of the newborns with polycythaemia (74-90%) are asymptomatic (11,12). In symptomatic newborns, hyperviscosity, decrease in tissue perfusion, and metabolic complications such as hypoglycaemia and hypocalcaemia are responsible for most clinical signs (13).
 In severely symptomatic newborns with polycythaemia, central nervous system disorders are commonly seen (14) which is attributed to both physiological reduction in cerebral blood flow and hypoglycaemia. Of the metabolic problems, the most commonly encountered is  hypoglycaemia (12-40%) and Hypocalcaemia is the next most common metabolic derangement and is found in 1-11% of neonates with polycythaemia.  At least one third of infants with polycythaemia develop Hyperbilirubinemia(3).
 Although polycythaemia and hyperviscosity have been suggested responsible for the pathogenesis of necrotizing enterocolitis in term and near-term newborns (15,16), partial exchange transfusion itself, performed to lower the hematocrit, has been reported to cause necrotizing enterocolitis(17).
Renal problems encountered in polycythaemia are decrease in glomerular filtration rate, oliguria, haematuria, proteinuria and renal vein thrombosis (16,39).
Thrombocytopenia, low antithrombin III levels, and more rarely development of thrombosis are haematological problems encountered in polycythaemia [9,11]. As the density of the erythrocytes increases they accumulate in the center of blood flow, and thrombocytes, which are lighter, migrate to periphery of the vascular wall (thrombocyte margination). This causes the number of thrombocytes to be counted lower than the actual count (relative thrombocytopenia) (14).

Table 2

Signs & Symptoms



Altered consciousness



Feeding problem





Necrotising enterocolitis






Renal vein thrombosis

Respiratory distress



Low Anti Thrombin III levels

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Current Recommendations:

  • At present there is no evidence to support the treatment of asymptomatic babies (or those babies with only mild symptoms) with partial exchange transfusion (PET) regardless of their PCV(17) hence there is no indication to check a PCV in an asymptomatic baby who is plethoric without any risk factors.
  • There is no evidence of long term benefit from partial exchange transfusion in polycythaemia infants, and the incidence of gastrointestinal injury is increased (e.g. NEC). The long term outcome is more likely to be related to the underlying cause of polycythaemia or associated conditions like hypoglycaemia etc (17, 18, 19).
  • Babies with significant neurological symptoms or progressive symptoms can be treated with PET (19).
  • Crystalloid solutions are as effective as colloid solutions for partial exchange transfusion, with no risk of transmission of blood-borne diseases and anaphylaxis. The use of crystalloid should be the standard practice for partial exchange transfusion (20,21)unless indicated otherwise.

Please refer to Flow Chart 1.


Flow Chart 1:

Laboratory tests to consider in symptomatic babies with polycythaemia:

  • Serum Glucose and Calcium levels (as most common metabolic derangements).
  • Serum Bilirubin: likely to have hyperbilirubinaemia due to increased red cell mass
  • FBC - to monitor Haemoglobin, haematocrit and sometimes they can have thrombocytopenia.
  • Electrolytes and kidney function tests especially in oliguric/anuric babies.


  • Consider cranial USS, MRI, Renal USS and Doppler’s if clinically indicated.

If in doubt, please discuss with your senior.

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Partial Exchange Transfusion:

This should always be discussed with the consultant.
This is a procedure to correct polycythaemia without hypovolaemia. The desired PCV is 50-55% and to achieve this 20ml/kg of blood is exchanged for normal saline.

Prior to procedure:

  • Informed written consent to be taken from parents as procedure is with significant risks.
  • Place baby nil by mouth, insert NGT and empty the stomach and put on free drainage.
  • It is important to stabilise baby hence to treat hypoxia, hypoglycaemia, acidosis etc before commencing the procedure
  • Cannulate umbilical vein, ensure tip of line is not in the liver (can also be done via peripheral arterial line/peripheral vein if no umbilical lines).
  • Record baseline observations before commencing the procedure.
  • Prescribe 0.9% Sodium chloride and calculate how much blood to be withdrawn in total and divide it by 4 (this will be equivalent to 20 mls/kg divided by 4).
  • Investigations
  • FBC, U+E LFT, Calcium, glucose, gas


  • Full aseptic precautions to be taken.
  • Procedure should be in ICU, baby to be on continuous monitoring including temperature and with BP monitoring every 15 minutes.
  • Set infusion of normal Saline 20ml/kg running over 1 hour via peripheral cannula.
  • In same hour remove 4 aliquots of 5ml/kg of blood. (every 15 minutes, each cycle to take at least 5 minutes)

Post- procedure care:

  • Continue to monitor for at least 2 hours.
  • Check FBC, U&Es, Calcium, blood gas, blood sugar at the end of procedure.
  • Repeat FBC after 4 hours
  • Restart feeds 4 hours after exchange unless clinical concerns raised. (i.e abdominal distension/discolouration, abnormal NG aspirate, abnormal stools.)
  • Ensure clear documentation of procedure.


  • Hypothermia-ensure fluids are warmed
  • Respiratory distress.
  • Fluid overload/fluid loss
  • Electrolyte disturbance
  • Infection
  • Line complications- haemorrhage, embolism, infection etc
  • Necrotising Enterocolitis.

(Please refer to local guidelines for Exchange transfusion for more details)


Record: 2160
Clinical condition: Polycythaemia in the newborn baby
Target patient group: Neonates
Target professional group(s): Secondary Care Doctors
Adapted from:

Evidence base

  1. Luchtman-Jones L, Wilson DB. Hematologic problems in the fetus and neonate. In: Neonatal-Perinatal Medicine, 9, Martin RJ, Fanaroff AA, Walsh MC (Eds), Elsevier Mosby, St. Louis 2011. p.1303.
  2. Oski FA, Naiman JL. Polycythemia and hyperviscosity in the neonatal period. In: Hematologic Problems in the Newborn, 3 ed, Oski FA (Ed), WB Saunders, New York 1982. p.87.
  3. Wiswell TE, Cornish JD, Northam RS. Neonatal polycythemia: frequency of clinical manifestations and other associated findings. Pediatrics 1986; 78:26.
  4. Stevens K, Wirth FH. Incidence of neonatal hyperviscosity at sea level. J Pediatr 1980; 97:118.
  5. Ramamurthy, RS. Neonatal polycythemia and hyperviscosity; state of the art. PerinatologyNeonatology 1979; 3:38
  6. Mimouni FB, Merlob P, Dollberg S, Mandel D; Israeli Neonatal Association. Neonatal polycythaemia: critical review and a consensus statement of the Israeli Neonatology Association. Acta Paediatr. 2011. Oct;100(10):1290-6. doi: 10.1111/j.1651-2227.2011.02305.x. Epub 2011 May 5. PMID: 21457305.
  7. Host A, Ulrich M. Late prognosis in untreated neonatal polycythaemia with minor or no symptoms. Acta Paediatrica 1982;71:629-633.
  8. Ramamurthy RS, Brans YW. Neonatal polycythemia: I. Criteria for diagnosis and treatment. Pediatrics. 1981 Aug;68(2):168-74. PMID: 7267222.
  9. Rosenkrantz TS, Philipps AF, Knox I, Zalneraitis EL, Porte PJ, Skrzypczak PE, Raye JR. Regulation of cerebral glucose metabolism in normal and polycythemic newborn lambs. J Cereb Blood Flow Metab. 1992 Sep;12(5):856-65. doi: 10.1038/jcbfm.1992.117. PMID: 1506450.
  10. Drew JH, Guaran RL, Grauer S, Hobbs JB. Cord whole blood hyperviscosity: measurement, definition, incidence and clinical features. J Paediatr Child Health. 1991 Dec;27(6):363-5. doi: 10.1111/j.1440-1754.1991.tb00420.x. PMID: 1756079.
  11. Black VD, Lubchenco LO, Koops BL, Poland RL, Powell DP. Neonatal hyperviscosity: randomized study of effect of partial plasma exchange transfusion on long-term outcome. Pediatrics. 1985 Jun;75(6):1048-53. PMID: 4000778.
  12. Black VD, Lubchenco LO, Luckey DW, Koops BL, McGuinness GA, Powell DP, Tomlinson AL. Developmental and neurologic sequelae of neonatal hyperviscosity syndrome. Pediatrics. 1982 Apr;69(4):426-31. PMID: 6175948.
  13. Upadhyay A, Aggarwal R, Deorari AK, Paul VK. Polycythemia in the newborn. Indian J Pediatr. 2002 Jan;69(1):79-82. doi: 10.1007/BF02723782. PMID: 11876126.
  14. Sarici SU, Ozcan M, Altun D (2016) Neonatal Polycythemia: A Review. Clin Med Rev Case Rep 3:142. 10.23937/2378-3656/1410142
  15. Lambert DK, Christensen RD, Henry E, Besner GE, Baer VL, Wiedmeier SE, Stoddard RA, Miner CA, Burnett J. Necrotizing enterocolitis in term neonates: data from a multihospital health-care system. J Perinatol. 2007 Jul;27(7):437-43. doi: 10.1038/sj.jp.7211738. Epub 2007 Mar 29. PMID: 17392837.
  16. Martinez-Tallo E, Claure N, Bancalari E. Necrotizing enterocolitis in full-term or near-term infants: risk factors. Biol Neonate. 1997;71(5):292-8. doi: 10.1159/000244428. PMID: 9167850.
  17. Ozek E, Soll R, Schimmel MS. Partial exchange transfusion to prevent neurodevelopmental disability in infants with polycythemia. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD005089. doi: 10.1002/14651858.CD005089.pub2. PMID: 20091569.
  18. Garcia-Prats JA. Neonatal polycythaemia. UpToDate accessed 26th May 2021.
  19. Dempsey EM, Barrington K. Short and longterm outcomes following partial exchange transfusion in the polycythaemioc newborn: a systematic review. Archives of disease in childhood. 2006;91:F2-F6
  20. de Waal KA, Baerts W, Offringa M. Systematic review of the optimal fluid for dilutional exchange transfusion in neonatal polycythaemia. Arch Dis Child Fetal Neonatal Ed. 2006 Jan;91(1):F7-10. doi: 10.1136/adc.2004.063925. PMID: 16371393; PMCID: PMC2672658.
  21. Dempsey EM, Barrington K. Crystalloid or colloid for partial exchange transfusion in neonatal polycythaemia: A systematic review and metanalysis, Acta Paediatrica, 94:11;1650-1655

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Trust Clinical Guidelines Group

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