Conservative therapy for hyperbilirubinemia
The mainstay of non-invasive HDN treatment is a combination of infusion support and light exposure.
Phototherapy aims to break down unconjugated bilirubin in the skin into water-soluble derivatives. The procedure is performed in an incubator using daylight or blue lamps (the optimal wavelength is 460–480 nm). The irradiation regimen can be either continuous or pulsed.
Infusion therapy is calculated based on the physiological requirement of the newborn (100–150% of the norm is administered). The following solutions are used:
- 5% albumin solution: 8–10 ml/kg;
- Plasma: 10–15 ml/kg.
In moderate HDN, therapy is supplemented with fluid administration to prevent cholestasis and reduce intestinal bilirubin absorption. The total volume is 50–100 ml/day. The infusion includes 5% dextrose solution, magnesium sulfate solution (5–8 ml/kg), and 4% potassium chloride solution (5–8 ml/kg).
Exchange blood transfusion (EBT)
ET remains the primary method for treating severe hyperbilirubinemia. The strategy depends on the timing of the procedure:
- Early ET (1st–2nd day of life): aims to remove toxic bilirubin and erythrocytes blocked by maternal antibodies from the bloodstream, as well as to increase hemoglobin levels.
- Late ET (from the 3rd day of life): the main goal is to prevent severe bilirubin encephalopathy.
Indications for early ET:
- Total cord blood bilirubin exceeds 100 µmol/L.
- Hourly bilirubin increase of more than 10 µmol/L in full-term infants.
- Hourly increase of more than 8 µmol/L in preterm infants.
Indications for late ET:
- Total bilirubin above 308–340 µmol/L in full-term newborns.
- Total bilirubin above 272–290 µmol/L in preterm infants (with a body weight over 2000 g).
Rh incompatibility features: transfusion uses either group-specific Rh-negative blood or a mixture of Rh-negative packed red blood cells with plasma of the same blood group as the child.
Management of hydrops fetalis
The hydropic form requires emergency volume replacement of circulating blood volume (CBV) and correction of severe anemia.
Action algorithm:
- Immediately after birth, partial ET is performed until the hemoglobin level reaches over 140 g/L.
- Then, total ET is performed using packed red blood cells and fresh frozen plasma (calculated volume: 150–180 ml/kg of body weight).
Symptomatic therapy:
- In pulmonary edema and severe respiratory failure, mechanical ventilation (MV) is indicated until complete stabilization of the condition.
- In severe ascites, ultrasound-guided paracentesis is performed. Ascitic fluid must be removed extremely slowly to avoid sharp hypotension.
- In myocardial dystrophy and heart failure, inotropic drugs are prescribed.
- Early prevention of cholestasis is mandatory.
Important: phototherapy in hydrops fetalis is strictly limited. This is due to the risk of massive conjugated bilirubin accumulation, which can lead to bronze baby syndrome.
Prevention of immune sensitization
Basic principles include strict adherence to Rh compatibility during blood transfusions and preservation of the first pregnancy in Rh-negative women. Specific prevention consists of administering human anti-Rh Rh0(D) immunoglobulin. The drug contains antibodies that bind fetal antigens in the maternal bloodstream, which inhibits her own immune response.
Postnatal prevention: Indicated for women without sensitization signs after delivery of an Rh-positive infant, as well as after any pregnancy termination (abortion, ectopic pregnancy).
- Dose: 1500 IU (300 µg) intramuscularly, single dose.
- Timing: for postpartum women — no later than 72 hours after delivery (optimally in the first 2 hours); after pregnancy termination — immediately upon completion of the procedure.
Antenatal prevention: Transplacental passage of fetal erythrocytes begins at 28 weeks. Prevention is indicated for all non-immunized pregnant women with Rh-negative blood (if the father is Rh-positive).
- Timing: 28 weeks of gestation.
- Dose: 1250–1500 IU (250–300 µg). A special drug that does not cross the placenta is used.
- If the timing is missed, the drug is administered as soon as possible (in the absence of antibodies).
- Upon the birth of an Rh-positive child, a repeat dose must be administered within 72 hours.
Additional indications for administration: threatened abortion with bloody discharge, abdominal trauma, embryo reduction in multiple pregnancies, and invasive procedures (amniocentesis, cordocentesis, chorionic villus sampling, cervical cerclage for cervical incompetence).
Briefly: answers to topical questions
What blood is used for exchange transfusion specifically in ABO incompatibility?
A combination of packed red blood cells and fresh frozen plasma is used for exchange transfusion in ABO incompatibility.
According to media selection rules, in case of ABO incompatibility, the following are used:
- Packed red blood cells — universal group 0(I) red blood cells.
- Plasma — AB(IV) plasma or the same group as the child.
What clinical symptoms are characteristic of the icteric form of ABO incompatibility?
The icteric form of ABO incompatibility is characterized by the appearance of clinical symptoms shortly after birth, usually in the first week of life.
The main manifestations of the disease include:
- Jaundice of the skin — associated with the formation of unconjugated bilirubin as a result of hemolysis.
- Hepatosplenomegaly — enlargement of the liver and spleen due to stimulation of extramedullary hematopoiesis.
A severe complication of hyperbilirubinemia is kernicterus with bilirubin accumulation in the basal ganglia.
What laboratory signs confirm the diagnosis of ABO incompatibility in a newborn?
The diagnosis of ABO incompatibility is confirmed by determining the blood groups of the mother and child, as well as detecting IgG antibodies.
The main laboratory signs include:
- Maternal blood group — type I (0) blood group.
- Child's blood group — in the described clinical case, A(II) Rh+ with maternal 0(I) Rh+.
- Presence of antibodies — anti-A and anti-B IgG class antibodies capable of crossing the placenta and causing erythrocyte destruction.
The specified blood group combination corresponds to an ABO immunological conflict.
To quickly memorize the indications for early exchange blood transfusion, use the "100-10-8" rule: cord blood bilirubin greater than 100, hourly increase in term infants — 10, in preterm infants — 8 µmol/L.
Class and exam questions
What is the fundamental difference between early and late exchange blood transfusion?
Early exchange blood transfusion (in the first two days) is performed to remove bilirubin and antibody-coated erythrocytes from the bloodstream. Late exchange transfusion (from the third day onwards) is aimed exclusively at preventing severe bilirubin encephalopathy.
Is it necessary to monitor the antibody titer after antenatal prophylaxis at 28 weeks?
No. If anti-Rh0(D) immunoglobulin prophylaxis was performed correctly, subsequent determination of Rh antibodies in the pregnant woman's blood has no clinical significance.
How to properly manage pronounced ascites in the hydrops form of HDN?
Paracentesis under mandatory ultrasound guidance is indicated. Ascitic fluid should be drained very slowly to prevent the development of hypotension in the newborn.
Why is the use of phototherapy restricted in the hydrops form of HDN?
In such patients, phototherapy may lead to excessive accumulation of direct bilirubin. This is a triggering factor for the development of a specific complication — bronze baby syndrome.
What else to study on this topic
- Mechanism of indirect bilirubin transformation under the influence of 460–480 nm light.
- Pharmacodynamics of drugs for the prevention of cholestasis in newborns.
- Technique of partial and total exchange blood transfusion.
- Features of the management of pregnant women after invasive procedures (cordocentesis, amniocentesis).
- Pathophysiology of the development of bronze baby syndrome.
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