What Is Neonatal Anemia?

1. Prenatal hemorrhage is mainly transplacental blood loss, including fetal-placental hemorrhage, fetal-maternal blood transfusion, and twin-to-natal blood transfusion. Due to the concealed bleeding, the amount of bleeding varies, and the bleeding rate can be urgent and slow, so the clinical manifestations are different.

Neonatal anemia

Neonatal anemia refers to venous hemoglobin (Hb) below 130g / L (13g / dl), or capillary Hb <145g / L (14.5g / dl), which can be diagnosed as neonatal anemia. With the in-depth understanding of the pathophysiology of neonatal anemia, the treatment plan for anemia has been continuously updated.

Causes of neonatal anemia

2. Most of the blood loss during childbirth is caused by obstetric accidents during delivery, malformations of placenta and umbilical cord.

(1) Abnormal placenta: Severe blood loss often occurs in placenta previa, early placental dissection, or misplaced placenta during cesarean section, which results in blood loss. Placental malformations are more common with multilobed placenta, and each leaf issues a fragile vein branching to the placenta. The blood vessel is prone to rupture and bleeding.

(2) Umbilical cord abnormality: The normal umbilical cord may suddenly bleed due to excessive drag, umbilical cord deformities such as umbilical hemangioma, vagus blood vessels, etc. The latter is that the umbilical cord divides one or more blood vessels before it reaches the place where it is implanted. , Lack of protection of umbilical cord-like tissue, easy to rupture; umbilical cord is implanted in the placenta, blood vessels also pass between the amniotic membrane and chorion without protection, the incidence of bleeding is 1% to 2%.

3. Postpartum blood loss Postpartum blood loss is more common in umbilical, gastrointestinal, and internal bleeding. In recent years, blood loss due to diagnostic blood collection in hospitals has also increased.

Essentials for diagnosis of neonatal anemia

Neonatal anemia

Neonatal anemia can be caused by blood loss, hemolysis, and low red blood cell (RBC) production. Blood loss can occur before birth (placental-placental, fetal-fetal, fetal-maternal blood transfusion), at birth (rupture of umbilical cord, placenta previa), and after birth (intracranial hemorrhage, visceral rupture). The most common cause of hemolysis is maternal and child blood type incompatibility. It can also be caused by maternal autoimmune diseases, drugs, intrauterine infections, and neonatal RBC membrane or enzyme defects. Low RBC production is extremely rare in the neonatal period.

Clinical manifestations of neonatal anemia

Acute anemia is usually caused by blood loss, often with paleness, shortness of breath, increased heart rate, and hypotension. Hematocrit (HCT) can be normal at first, but can be reduced within 6 hours due to blood dilution. Chronic anemia may be pale, but there are no clinical distress symptoms due to compensation, liver and spleen may be enlarged, and congestive heart failure may occur in some children.

Neonatal anemia laboratory test

(1) Find the cause of anemia immediately Check the placenta; Observe the RBC morphology and net RBC count on the blood smear; Direct coombs test; Maternal blood smear calculate the ratio of fetal RBC to maternal RBC (acid elution method) to exclude the fetus -Maternal blood transfusion.

(2) Other selective tests Specific IgM antibody measurement (rubella, CMV, toxoplasma, parvovirus B19); stopping, coagulation test; RBC enzyme measurement and Hb electrophoresis; imaging examination to find the bleeding site.

Neonatal anemia physiological anemia

Hb in umbilical cord blood in preterm infants is similar to that in term infants, but physiological anemia occurs early (4-6 weeks) and is heavy (Hb 70-100g / L). The younger the gestational age, the more severe the anemia, and the longer it lasts. This is mainly due to low levels of erythropoietin (EPO) in preterm infants, and is also related to short RBC life and frequent diagnostic blood draws in preterm infants.

Neonatal anemia treatment

Emergency management for acute blood loss in neonatal anemia

If the child is in shock, immediately infuse 15-20ml / kg 5% albumin, normal saline or whole blood to restore blood volume to normal. Chronic severe anemia caused by incompatibility hemolytic disease needs to be corrected by early blood exchange.

Neonatal anemia in non-emergency situations

Anemia can be corrected by infusion of concentrated RBC. Indications for blood transfusion: Accumulated blood volume> 10% of blood volume within 72 hours; Hb <130g / L (HCT <0.4) in children with acute anemia; Hb <80 100g / L (HCT < 0.25 to 0.30) and clinical signs of anemia (shortness of breath, tachycardia, repetitive apnea, need for low flow oxygen, difficulty feeding, weight gain, etc.).

The amount of blood transfusion can be calculated according to the following formula:

Blood transfusion volume (ml) =

Expected HCT-HCT in children

Donor HCT

× weight (kg) × 90

(rHuEPO) Recombinant human erythropoietin (rHuEPO) for neonatal anemia

The use of recombinant human erythropoietin (rHuEPO) can increase Hb levels and reduce the number of blood transfusions in preterm infants, but it cannot eliminate the need for blood transfusion in preterm infants. The dose is 200 ~ 250u / kg each time, and is subcutaneously injected 3 times a week. Iron should be added at the same time 4 ~ 8mg / kg.d (at least 2mg / kg.d).

Neonatal anemia nutrition supplement

(1) The cause of physiological anemia of iron in preterm infants has nothing to do with iron, but iron reserves in preterm infants decrease after 2 to 3 months of birth. Iron supplementation should be started 4 to 6 weeks after birth at a dose of 1 to 2 mg / kg per day.

(2) Both VitE breast milk and modern formula milk contain sufficient VitE and low content of polyvalent unsaturated fatty acids, so VitE deficiency has rarely occurred.

(3) Folic acid: Both breast milk and formula contain sufficient folic acid, so it is generally not necessary to supplement it, unless the infants on special diets (such as phenylketonuria and maple diabetes) are at risk of folic acid deficiency.