Referral
Subject: Referral for Evaluation of a Neonate with Suspected Down Syndrome and Haematological Abnormalities
Dear Colleague,
I am referring a 2-day-old neonate, a full-term male delivered vaginally, who has exhibited facial features suggestive of Down syndrome. Post-delivery, he was admitted to the Neonatal Intensive Care Unit (NICU) due to transient tachypnoea of the newborn, necessitating minimal supplemental oxygen.
Clinical Presentation and Initial Laboratory Findings:
- Facial Features: Indicative of Down syndrome.
- Respiratory: Managed in the NICU for transient tachypnoea; currently stable with minimal oxygen support.
- Haematology:
- Initial Haemoglobin: 23.9 gm/dl, which subsequently increased to 25 gm/dl.
- Haematocrit: Rose from 67.2% to 71%.
- Platelets: Decreased to 81,000.
- Metabolic: Experienced an episode of hypoglycaemia.
Given the constellation of clinical and haematological signs particularly the elevated haemoglobin and haematocrit levels that raised our concern, a comprehensive evaluation is recommended from your side.
Thank you for your attention to this matter. We look forward to your expertise in further managing and elucidating this case. Please do not hesitate to contact me if you require any further details or specific information prior to your evaluation of the patient.
Reply
Dear Colleague,
Thank you for referring the 2-day-old neonate for further assessment and management. Upon review, we gathered that the infant was delivered at home and received medical attention upon arrival at the hospital where late clamping of the umbilical cord was performed.
Clinical Findings:
- Facial Features: The infant exhibits characteristic features of Down syndrome.
- Respiratory Status: He is well and active, with stable vital signs, requiring 0.5 L of oxygen to maintain an O2 saturation of approximately 96%.
- Physical Examination: The chest examination is normal, and a review of other systems revealed no additional concerns.
Laboratory Results:
- The haematological evaluation confirmed elevated haemoglobin and haematocrit levels, indicative of neonatal polycythaemia.
- Mild thrombocytopenia was also noted, which we will continue to monitor closely.
Initial impression:
Neonatal polycythaemia due to delayed cord clamping.
Recommendations:
- Intravenous Fluids: Initiation of IV fluids to ensure hydration and assist in diluting the elevated haematocrit.
- Monitoring Critical Levels: Particular attention will be given to monitoring calcium, glucose, and serum bilirubin levels to manage and pre-empt potential complications.
- Echocardiography: Scheduled to assess for congenital heart defects, which are common in infants with Down syndrome.
- Close Monitoring: We will continue to closely monitor the neonate, particularly his haematocrit levels. Should they remain above 70% or if he shows signs of becoming more symptomatic, a partial exchange transfusion may be considered as a therapeutic option.
We appreciate the thoroughness of your initial evaluation and are committed to providing the specialized care required for his condition. We will ensure to keep you updated on his progress and any further interventions that might become necessary.
Case follow up:
The baby improved gradually, and he didn’t require exchange transfusion, and discharged home in good general condition.
Discussion
Neonatal polycythaemia is characterized by elevated haematocrit or haemoglobin that are greater than two standard deviations than the norm for an infant’s gestational and postnatal age. Specifically, a term infant is considered polycythaemia if the haematocrit exceeds 65 percent or if haemoglobin levels surpass 22 g/dL when measured from a peripheral venous sample.
Epidemiology and Risk Factors
Polycythaemia is observed in approximately 0.4% to 12% of newborns, with a higher incidence noted in infants who are either small for gestational age (SGA) or large for gestational age (LGA). The condition can be associated with maternal diabetes, twin-to-twin transfusion syndrome, and conditions leading to intrauterine hypoxia, which may stimulate increased erythropoiesis as a compensatory mechanism.
Impact of Delayed Cord Clamping
The practice of delayed umbilical cord clamping, typically performed 1 to 3 minutes after birth, has been shown to increase neonatal haematocrit and haemoglobin levels. This intervention is beneficial in preventing anaemia and improving iron stores in newborns. A meta-analysis by Hutton and Hassan identified a slight increase in the risk of developing polycythaemia associated with delayed cord clamping at both 7 hours after birth (RR, 3.44; 95% CI, 1.25–9.52; two trials; n = 236) and at 24 to 48 hours after birth (RR, 3.82; 95% CI, 1.11–13.21; 7 trials; n = 403).; however, it is crucial to note that these instances of polycythaemia were largely asymptomatic and did not necessitate intervention. This suggests that while the practice does elevate haematocrit levels, it does not commonly lead to symptomatic disease or significant maternal blood loss.
| Investigation | Purpose |
| Complete Blood Count (CBC) | High haematocrit confirms polycythaemia; may require additional hematologic tests. |
| Blood Film | To examine the morphology of blood cells and check for abnormal cells. |
| Glucose Level | Hypoglycaemia requires immediate correction to prevent neurological damage. |
| Thyroid functions (TSH, T3, T4) | Thyroid dysfunctions can be a contributory factor to polycythaemia. |
| Immunoglobulin Levels | High levels of IgM, IgA may suggest maternal-foetal transfusion as an etiology. |
| Cranial ultrasound (if low platelets) | Thrombocytopenia in polycythaemia can increase the risk of bleeding complications. |
Management Strategies
The management of neonatal polycythaemia depends largely on the presence and severity of symptoms:
- Asymptomatic Infants (Haematocrit 65-75%): These infants should undergo regular cardiorespiratory monitoring along with periodic checks of haematocrit and glucose levels every 6-12 hours. Observation should continue for at least 24 hours or until haematocrit levels decrease.
- Asymptomatic Infants with Haematocrit >75%: In cases where high haematocrit levels persist, a partial exchange transfusion may be considered to reduce the risk of complications associated with hyperviscosity.
- Symptomatic Infants (Haematocrit 60-65%): Symptoms in this range should prompt clinicians to investigate alternative causes alongside polycythaemia and hyperviscosity, as other conditions could be contributing to the clinical presentation.
- Symptomatic Infants with Haematocrit >65%: If symptoms can be directly attributed to polycythaemia and hyperviscosity, management may include partial exchange transfusion. This is particularly indicated if initial measures such as hydration do not alleviate symptoms, or if the infant’s condition worsens.
Partial exchange transfusion (PET) is predominantly safe but is not devoid of potential risks. The incidence of complications associated with this procedure ranges from 0.5% to 3.3%. These complications are often transient and include conditions such as bradycardia, apnoea, severe thrombocytopenia, hypocalcaemia, and hypokalaemia. With proper medical care and monitoring, recovery from these transient conditions is generally expected.
However, PET can lead to severe, and occasionally fatal, complications including cardiovascular collapse, necrotizing enterocolitis (NEC), bacterial sepsis, and pulmonary haemorrhage. These critical conditions can often be mitigated through diligent monitoring of oxygen saturation and cardiopulmonary function. It is noteworthy that NEC, although rare, is more likely to occur in neonates with conditions such as polycythaemia or hyperviscosity; about 44% of term neonates diagnosed with NEC also present with polycythaemia. Recent studies suggest that polycythaemia may not significantly contribute to the development of NEC in term infants and may be associated with the use of colloids in PET to reduce haematocrit levels.
Additionally, polycythaemia in neonates can lead to hypoglycaemia, the most common metabolic complication observed in 12% to 40% of affected infants. It also impacts coagulation; however, disseminated intravascular coagulation remains rare. In a Dutch study, thrombocytopenia was observed in 51% of neonates with polycythaemia, with severe thrombocytopenia affecting 91% of 140 studied cases.
Ultimately, polycythaemia increases blood viscosity, which impairs microcirculatory flow and may result in a spectrum of clinical manifestations including neurological, gastrointestinal, cardiopulmonary, renal, thrombotic, and metabolic issues.
Conclusion
While neonatal polycythaemia often resolves with minimal intervention, careful monitoring and appropriate management are crucial to prevent complications associated with hyperviscosity. Continued research and clinical observation are needed to optimize guidelines for the identification, monitoring, and treatment of this condition, ensuring outcomes are maximized for affected infants.
Check the correct answers.
Question-1:
Correct Answer: D) A mother with gestational diabetes mellitus (GDM) poorly controlled on diet alone
Explanation: Gestational diabetes mellitus, especially when poorly controlled, is a well-documented risk factor for neonatal polycythaemia. High maternal blood glucose levels can lead to foetal hyperglycaemia, which stimulates increased foetal insulin production and subsequent erythropoiesis, raising the risk of polycythaemia in the newborn. The other conditions listed, such as well-controlled hypothyroidism and untreated celiac disease, do not have a direct, well-documented impact on increasing erythropoietic activity leading to neonatal polycythaemia. External cephalic version, while associated with some foetal stress, does not typically impact foetal erythropoiesis to the extent seen with uncontrolled gestational diabetes.
Question-2:
Correct Answer: B) Cranial ultrasound to check for intracranial hemorrhage
Explanation: In neonates with polycythaemia and significant hyperviscosity symptoms, especially when neurological signs such as altered mental status are present, a cranial ultrasound is critical to exclude intracranial haemorrhage before proceeding with partial exchange transfusion (PET). Intracranial haemorrhage is a severe complication that may necessitate different management approaches and has implications for the prognosis. While an echocardiogram and blood film may provide useful information regarding other potential issues, and a Direct Coombs test could exclude immune-mediated causes of anaemia, the urgency and potential severity of intracranial haemorrhage make the cranial ultrasound the most critical investigation under these circumstances.
References
- Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full-term neonates: Systematic review and meta-analysis of controlled trials. JAMA. 2007; 297:1241–1252.
- McDonald SJ, Middleton P. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes (review). Cochrane Database Syst Rev. 2008; 2:CD004074.
- 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.
- 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.
- Vlug RD, Lopriore E, Janssen M, Middeldorp JM, Rath ME, Smits-Wintjens VE. Thrombocytopenia in neonates with polycythemia: incidence, risk factors and clinical outcome. Expert Rev Hematol. 2015;8(1):123–9.
- Dempsey EM, Barrington K. Short and long term outcomes following partial exchange transfusion in the polycythaemic newborn: a systematic review. Arch Dis Child Fetal Neonatal Ed. 2006;91(1):F2–6.
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