ANEMIA IN NEWBORN

Considering developmentally higher hemoglobin levels in normal newborn, neonatal anemia is defined as Hb lt;13 gm in fullterm and lt;12 gm/dl in preterms, during first two weeks of life.

Etiology: Transplacental iron transfer is an active process, not affected by maternal Hb levels and maternal anemia is unlikely to cause neonatal anemia. however, since maximum iron transfer through placenta occurs in last trimester, preterms are anemic.

Rh/ABO incompatibility, perinatal blood loss and sepsis are three most important causes of anemia in newborn, apart from others (Table 12.56). Repeated blood sampling is an important cause of severe anemia in neonatal intensive care.

Fetomaternal hemorrhage, though occurs in ~50% pregnancies, is rarely enough to cause significant neonatal anemia (lt;1%).

Clinical evaluation of neonatal anemia includes:

• Family history of hereditary hemolytic anemia

• Maternal blood group (Rh/ABO incompatibility)

• Prenatal history of infections or invasive procedures

• History of multiple pregnancy (twin-twin transfusion) and cord clamping time.

• Co-existing problems: Cephalohematoma, severe edema (hydrops), hepatosplenomegaly, icterus, sepsis, etc.

TABLE 12.56: Causes of severe anemia in newborn

Increased blood loss

• Fetal: Feto-fetal or feto-maternal hemorrhage

• Placental: Placenta previa. antepartum hemorrrhage

• Cord: Early/late clamping, trauma, anomalies.

• Birth injuries: Cephalohematoma

• Bleeding neonate

Increased RBC destruction

• Hemolytic disease of newborn (Rh/ABO)

• Congenital hemolytic anemia

• Acquired hemolysis: Sepsis, IU infections, drugs

Decreased RBC synthesis

• Anemia of prematurity

• Bone marrow hypoplasia: Drugs, IU Infection

• Bone marrow infiltration: Leukemia, osteopetrosis

Iatrogenic

• Repeated blood sampling

• Post-exchange (low Hb content in adult blood)

Laboratory evaluation: Fig. 12.24 provided a practical algorithm for laboratory diagnosis of neonatal anemia, though common investigations include:

• Complete hemogram including Hb, Hct, cell counts and Reticulocyte count

• P.

• Direct Coombs' test (Rh/ABO disease)

• Sepsis screen, including relevant cultures

• Serological tests for intrauterine infections

• Bone marrow examination (in selected cases)

• Coagulation profile (in bleeding disorders)

• Kleinhauer test

Kleihauer-Betke test is used to detect presence of fetal RBCs in maternal blood in fetomaternal hemorrhage, as follows:

Collect maternal smear along with controls from a normal newborn and adult gt; Fix them with 80% ethanol for 5 minutes gt; Rinse, dry and immerse in a buffer solution (73.4% of 0.1 M citric acid + 26.6% of 0.2 M disodium hydrogen phosphate) for 5 minutes gt; Hematoxylin-eosin staining gt; Examine under microscope. On microscopy, RBCs with acid-resistant fetal Hb remain darkly stained, while those with adult Hb appear like ghost cells, due to acid elution. Presence of ~ 1% of fetal RBCs in maternal smear indicates ~ 50 ml of fetal blood loss to maternal side.

Management of neonatal anemia depends on its severity, primary cause and associated problems. Packed RBC transfusion (15 ml/kg over 2-4 hours) is indicated according to the hemoglobin levels and clinical status of the newborn as follows:

• On mechanical ventilation @ Hb lt; 11 gm/dl

• On minimum respiratory support @ Hb lt; 10 gm/dl

• On oxygen or impending CCF @ Hb lt; 8 gm/dl

• Asymptomatic newborn @ Hb lt; 7 gm/dl

Anemia of prematurity may be prevented with recombinant erythropoietin therapy (25-100 U/kg SC alternate day) with PO iron (2 mg/kg/d) from 2^nd week onwards, though rarely practiced.

12.17.3