European Journal of Cardiovascular Medicine

An exchange transfusion involves the gradual removal of small aliquots of a patient’s blood and its replacement with donor blood to eliminate abnormal components and circulating toxins, while maintaining adequate blood volume. [1,2] This procedure is primarily performed to remove harmful antibodies and excess bilirubin in cases of isoimmune disease, such as hemolytic disease of the newborn (HDN). [2] Recent advances in the prevention and prenatal management of alloimmune hemolytic disease, as well as improved strategies for treating neonatal hyperbilirubinemia, have contributed to a significant decline in the incidence of exchange transfusion.[2]

Hyperbilirubinemia is more commonly seen in preterm and low birth weight neonates and they are more prone for development of kernicterus if intervention is not done on time. [3] Neonatal hyperbilirubinemia, particularly in relatively healthy term or late preterm infants (greater than 35 weeks’ gestation), can still carry risks for chronic sequelae, including kernicterus and acute bilirubin encephalopathy. [4,5] While mild to moderate elevations in serum bilirubin are generally considered benign, dangerously high levels can lead to bilirubin crossing the blood-brain barrier, potentially resulting in neurotoxicity. The threshold for bilirubin neurotoxicity varies based on factors such as birth weight, gestational age, and overall health. [5,6]

Severe neonatal hyperbilirubinemia is typically defined by a total serum bilirubin (TSB) concentration greater than 340 µmol/L (20 mg/dL) within the first 28 days of life. Critical hyperbilirubinemia is marked by a TSB exceeding 425 µmol/L (25 mg/dL). Approximately 60% of term newborns develop jaundice, and around 2% reach the severe hyperbilirubinemia threshold of 340 µmol/L.[4,6]

The evolving global and national healthcare landscapes have necessitated this study. Specifically, there was a need to clarify potentially related factors, such as the newborn's Rh status, due to the limited information currently available. This research aims to address these gaps by investigating key clinical factors involved in neonatal hyperbilirubinemia.

Research in fundamental areas such as Transfusion Medicine lays the groundwork for advancements in other medical fields. The present study is designed to explore the impact of neonatal maturity on various blood parameters before and after blood transfusion in cases of neonatal hyperbilirubinemia.

The findings of this research will provide valuable insights for clinicians, paediatricians, and healthcare professionals in diagnosing and treating neonatal hyperbilirubinemia. Additionally, the results will contribute to the broader scientific understanding of the condition, aiding researchers focused on neonatal health and hyperbilirubinemia management.

Study Type:    Interventional study without control

Study Design:   Longitudinal study

Study Period: 6 months

Study Area: The study was undertaken at the Department of Immunohematology & Transfusion Medicine and laboratories of SMS hospital, J K Lon Hospital and Mahila Chikitsalya, Jaipur.

Sample size: Sample size was calculated at 95% confidence level assuming a standard deviation of 9.7% in fall of serum bilirubin as preference study, at the precision of 3% fall in serum bilirubin minimum 40 cases were required as the sample size of the present study.

Inclusion Criteria: 

1. All neonates with Neonatal Hyperbilirubinemia requiring exchange transfusion and/or if requiring multiple exchange transfusions.2
2. Those giving consent for participation in this study.

Exclusion Criteria: Patients who may get benefit from phototherapy and blood transfusion and    

1. Don’t fall in the range of exchange transfusion criteria.
2. Major congenital malformations.
3. Those refusing consent for participating in this study.

Selection of study population was done as per inclusion and exclusion criteria. The detailed personal and medical history of the donor was recorded as per the proposed Performa. Information recorded were age, weight, and sex of the newborn neonate’s and Volume of Blood Transfusion. Investigations conducted in all neonates requiring exchange were total serum bilirubin (TSB), conjugated and unconjugated fractions of TSB, ABO, and Rhesus blood group; direct Coombs test (DCT), reticulocyte count and peripheral blood smear examination. Glucose-6-phosphate dehydrogenase (G6PD) levels, thyroid profile and sepsis screen were done wherever indicated.

Traditional guidelines suggest exchange transfusion in the following circumstances:

Within 12 hours of birth if

• Cord blood bilirubin concentration exceeds 3 to 5 mg/dL for preterm infants, 5 to 7 mg/dL for term infants, or the rate of increase is >0.5 mg/dL/hour.
• Severe anemia: hemoglobin 10 g/dl combined with hyperbilirubinemia.

After 24 hours of birth if

• Total bilirubin concentration >20 mg/dL or a bilirubin increase of >0.5mg / dL / hour or   hemoglobin     10g / dL   combined   with hyperbilirubinemia.

The study centre at SMS / JKLon hospital / Mahila Chikitsalya blood bank is licensed and fully equipped for component preparation with the facility of deep fridge centrifuge, laminar flow, plasma extractor, dielectric tube sealer, deep fridge of -40°C and -70°C, sterilized connecting device, cryo water bath etc. Whole Blood was supplied to neonatal hyperbilirubinemia cases requiring exchange transfusion, hospitalized in Newborn Care Unit attached with the present institute. All the cases of HDN were diagnosed by testing cord blood/neonate blood for ABO grouping and Rh typing (Tube technique), Direct Coomb's test (DCT) by Polyspecific AHG Column technique, total, direct and indirect serum bilirubin  (Autoanalyser method) along with mother's sample for ABO grouping, RhD typing (Tube technique).

Neonate’s Rh factor wise grouped was Rh+ve=37 (92.5%) and Rh−ve=03(7.5%). Neonate’s Rh factor wise grouped then the changes in haematological and biochemical parameters before and after exchange transfusion (Table-1 and Figure 1) When the When Neonate’s blood group was Rh +ve, then the Hb (g/dl) mean value before exchange transfusion was 12.87±0.16 and after exchange transfusion was 13.69±0.13. The P-value was 0.091. When Neonate’s blood group was Rh-ve, then the Hb (g/dl) mean value before exchange transfusion was 11.40±0.12 and after exchange transfusion was 12.30±0.40. The P-value was 0.705.

When Neonate’s blood group was Rh+ve, then the Haematocrit means value before exchange transfusion was 36.50±0.47% and after exchange transfusion was 40.16±0.39%. The P-value was 0.016. When Neonate’s blood group was Rh -ve, then the Haematocrit mean value before exchange transfusion was 38.45±0.79% and after exchange transfusion was 36.15±0.97%. The P-value was 0. 162.

When Neonate’s blood group was Rh +ve, then the Total bilirubin (mg/dl) means value before exchange transfusion was 21.87±0.41% and after exchange transfusion was 11.09±0.23%. The P-value was 0.001. When Neonate’s blood group was Rh-ve, then the Total bilirubin (mg/dl) mean value before exchange transfusion was 21.48±0.39 and after exchange transfusion was 14.40±1.43. The P-value was 0.300.

When Neonate’s blood group was Rh +ve, then the Direct bilirubin (mg/dl) mean value before exchange transfusion was 3.48±0.36 and after exchange transfusion was 1.04±0.04. The P-value was 0.032. When Neonate’s blood group was Rh -ve, then the Direct bilirubin (mg/dl) mean value before exchange transfusion was 0.78±0.00 36 and after exchange transfusion was 0.72±0.01. The P-value was 0.437.

When Neonate’s blood group was Rh+ve, then the Indirect bilirubin (mg/dl) mean values before exchange transfusion was 21.53±0.30 and after exchange transfusion was 10.08±0.22. The P-value was <0.001. When Neonate’s blood group was Rh -ve, then the Indirect bilirubin (mg/dl) mean value before exchange transfusion was 20.70±0.39 and after exchange transfusion was 13.68±1.42. The P-value was P <0.299.

Table-1: - Neonate’s Rh factor wise changes in haematological and biochemical parameters before and after exchange transfusion

*^{–Denotes significance difference in the Table}

Figure.1 Neonate’s Rh factor wise changes in hematological and biochemical parameters before (Pre ET) and after) Post ET) exchange transfusion

Neonate’s Rh factor wise grouped was Rh+ve=37 (92.5%) and Rh−ve =03(7.5%) whereas according to Singla, et al, 2017 [7] Neonate’s Rh factor wise grouped was Rh+ ve =48 (98 %) and Rh− ve=1(2 %), which was comparable to our results.

The present study was undertaken to establish if Rh status would play a role in altering the neonates' blood parameters who received exchange transfusions for hyperbilirubinemia. The parameters like hemoglobin (Hb), hematocrit, total bilirubin, direct bilirubin, and indirect bilirubin levels following exchange transfusion were included.

Comparing Hb values before and after the exchange transfusion, the differences were statistically not significant in both Rh+ and Rh- neonates with P = 0.091 in Rh+ and P = 0.705 in Rh-. This means that the effect of the exchange transfusion was insignificant on Hb values irrespective of the Rh status of the neonates. Since the main goal of an exchange transfusion in such a situation is the reversal of bilirubin, and not correction of anemia per se, Hb not having shown a marked change is within the expected clinical scenario.

Values of hematocrit underwent significant alteration in Rh-positive neonates prior to and post-exchange transfusion (P = 0.016), thus suggesting there was an effect of this procedure concerning blood volume and red cell concentration within those babies. In the Rh-negative group, there were no significant alterations regarding values of hematocrit (P = 0.162). This might be due to differences in the pathophysiological underlay between Rh-positive and Rh-negative hemolytic disease. Neonates who are Rh-positive and born to a RH negative mothers have a higher risk to suffer from HDN because of Rh incompatibility.

We observed that there is significant reduction of total bilirubin levels of Rh-positive neonates after undergoing an exchange transfusion (P < 0.001). This indicates that it could significantly reduce the cases of bilirubin toxicity as well as kernicterus, usually because they have a more severe hyperbilirubinemia caused by hemolysis. On the contrary, total bilirubin decrease was not significantly different in Rh-negative neonates (P = 0.300); hence the hyperbilirubinemia of this group could be less severe and driven by other factors apart from the basic reason of Rh incompatibility, thereby reducing the impact of the exchange transfusion.

The study also shows significant differences regarding bilirubin subtypes. Indirect bilirubin fell significantly at levels that were highly significant in Rh-positive neonates; thus, it put more emphasis on the efficiency of the exchange transfusion process in the removal of unconjugated bilirubin, which constitutes the primary cause of neurotoxicity in this setting. Direct bilirubin, however, was shown to alter nonsignificantly in Rh-positive (P = 0.032) as well as in Rh-negative (P = 0.437) neonates. This would indicate that the unconjugated bilirubin fraction is the most significant fraction impacted by exchange transfusion, consistent with its clinical goal of blunting the potential risks imparted by the accumulation of indirect bilirubin. [8]

For Rh-negative neonates, both direct and indirect bilirubin levels were not markedly altered from the preliminary measure after the performance of the exchange transfusion. This could therefore suggest that the root cause of hyperbilirubinemia for Rh-negative neonates is less severe hemolysis so there is less of a need to intervene with its treatment using exchange transfusion. Furthermore, in situations where Rh-negative babies are linked with hyperbilirubinemia, then pathogenesis may arise from mechanisms such as genetic disorders like Gilbert syndrome and not Rh incompatibility that partly explains why exchange transfusion would have such an insignificant effect.

The findings of this study help in establishing the role of Rh status on being vital to predict the outcome of exchange transfusion in neonatal hyperbilirubinemia. Rh-positive neonates, particularly with RH incompatibility appear to benefit most in terms of reduction of bilirubin, more importantly indirect bilirubin. Such is pivotal in the prevention of bilirubin encephalopathy and long-term neurodevelopmental impairment.

Limitation of the study: The sample size is small and based in only one center. Further research needs to be undertaken on other factors of great importance, such as ABO incompatibility, gestational age, and other genetic predispositions that may influence the effectiveness of exchange transfusion. Long-term outcomes post-transfusion can also provide more value-added information towards clarifying the clinical relevance of these findings.

In conclusion, in comparison to Rh-positive neonates with severe hyperbilirubinemia, the role of exchange transfusion in Rh-negative neonates may be reviewed or alternative treatments individualized based on specific causes of hyperbilirubinemia added to the therapy.

1. Hall CP, Lightfoot JK. Exchange Transfusion. [Updated 2022 Oct 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563179/
2. Carl P.The Exchange Transfusion Newer Concepts and Advances in Technic, Clinical Clinical pediatrics. 1968:7(7)383-388.
3. Watchko JF, Maisels MJ. "Jaundice in Low Birth Weight Infants: Pathophysiology, Prevention, and Treatment." Semin Neonatol 2002;7(2):101-108.
4. Stevenson DK, Fanaroff AA, Maisels MJ, MJ, Young BW, Wong RJ. Prediction of Hyperbilirubinemia in Near Term and Term Infants. Pediatrics,; 2001:108(1):31-9.
5. Maisels MJ. "Managing Hyperbilirubinemia in the Newborn Infant >35 Weeks of Gestation." Pediatrics 2004;114(1):297-316.
6. Bhutani VK, Johnson L, Shapiro SM. "Kernicterus: Epidemiological Strategies for Its Prevention through Systems-Based Approaches." J Perinatol 2005;25(10):700-712.
7. Singla, Deeksha A, Seema S, Milap S, Sanjeev C. Evaluation of Risk Factors for Exchange Range Hyperbilirubinemia and Neurotoxicity in Neonates from Hilly Terrain of India.International Journal of Applied and Basic Medical;2017: Research | Vol.7(4).
8. Reddy DK, Pandey S. Kernicterus. [Updated 2023 Jun 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559120/