Isoantigenic Incompatibility of Blood of Mother and Fetus. Pathologies of Neonatal Period.

Question 1

What is Rhesus isoimmunisation?

Answer 1

Immunologic disorder that occurs in a pregnant Rh - patient carrying a Rh + fetus; in which the immune system produces anti - Rh antibodies that cross the placenta causing hemolysis in the fetus.

Question 2

In which case would the first pregnancy involving an Rh - mother carrying an Rh + fetus be affected by rhesus isoimmunisation?

Answer 2

If the mother had a previous transfusion with Rh+ blood.

Question 3

What clinical symptoms would you expect to see in hemolytic disease?

Answer 3

Anaemia, jaundice and oedema.

Question 4

What are the features of the first stage of hemolytic disease?

Answer 4

Hb (g/L): 150
Bilirubin: 85.5
Subcutaneous oedema

Question 5

What are the features of the second stage of hemolytic disease?

Answer 5

Hb (g/L): 100 - 150
Bilirubin: 85.6 - 136.8
Oedema of subcutaneous fat and ascites

Question 6

What are the features of third stage of hemolytic disease?

Answer 6

Hb (g/L): 100
Bilirubin: 136.9
Hydrops fetalis

Question 7

What are the indications for haemotransfusion in a term fetus?

Answer 7

Indirect bilirubin: > 68.42 on day 1 and 300.7 on day 5;
Haemoglobin: < 150
Haematocrit: < 0.4

Question 8

What are the indications for haemotransfusion in a pre - term fetus?

Answer 8

Indirect bilirubin: > 59.9 on day 1 and 273.6 on day 5;
Haemoglobin: < 150;
Haematocrit: < 0.4.

Question 9

What complication can be caused by critical levels of indirect bilirubin?

Answer 9

Indirect bilirubin levels of 307.8 - 342 in a term fetus and 153 - 205 in a pre - term fetus can lead to nervous ganglia damage and result in Kernicterus.

Question 10

What in the patients history would indicate rhesus isoimmunisation?

Answer 10

Previous pregnancies, abortions, ectopic pregnancies, haemotransfusions.

Question 11

What laboratory diagnostics are used to diagnose rhesus isoimmunisation?

Answer 11

Assessing the Rh status of both parents and the fetus (DNA amplification). Coomb’s tets. Amniocentesis. Cordocentesis. Spectrophotometry of amniotic fluid.

Question 12

What antibody titre would be considered mild isoimmunisation and what would be considered severe? What would be the effects?

Answer 12

Mild: < 1: 16.
Severe: > 1: 16.
May lead to anaemia and hyperbilirubinaemia in the neonate and in the severe case: hydrops fetalis.

Question 13

What markers are you looking for in amniocentesis and cordocentesis?

Answer 13

Amniocentesis: bilirubin.
Cordocentesis: hematocrit, hemoglobin, blood gases and bilrubin.

Question 14

What is the optical density of bilirubin and in what test would it be necessary to know this information?

Answer 14

The OD of bilirubin is 450 nm. This information would be useful when performing spectrophotometry and using a Liley graph to determine the severity of rhesus disease.

Question 15

What signs would you look for on an ultrasound of a fetus with rhesus disease?

Answer 15

Hepatosplenomegaly; ascites; pleural effusion; pericardial effusion; skin oedema; polyhdramnion; hyperplasia of the placenta.

Question 16

What dose of RhoGAM (Rh immune Globulin) should be administered to a mother of a Rh + positive fetus?

Answer 16

300 mg

Question 17

When should RhoGAM be administered?

Answer 17

Within 72 hours after delivery; 
28 weeks gestation; 
At the time of amniocentesis; 
After positive Kleihauer - Betke test (fetal blood in maternal circulation);
After aborted ectopic pregnancy (50 mg).

Question 18

How does phytotherapy treat hemolytic disease in neonates?

Answer 18

Photochemical reaction that transforms fat - soluble isomer into water soluble isomer of bilirubin.

Question 19

What additional treatments could be performed?

Answer 19

Phenobarbital 5 - 10 mg / kg (bds / tds) (some evidence that it treats hyperbilirubinaemia);
Hemosorption.

Question 20

At what rate should blood transfusion occur in moderate to severe forms of hemolytic disease?

Answer 20

150 - 180 ml /kg. 10ml of blood should be let out to determine level of bilirubin. After every 100 ml of blood is reintroduced, 2ml of calcium gluconate should be administered.

Question 21

What are the principles of pre - term care?

Answer 21

Administration of surfactant, antenatal corticosteroids and prevention of hypothermia.

Question 22

What constitutes abnormal breathing in neonates?

Answer 22

RR > 60, periods of apnoea that last more than few seconds (may be accompanied with cyanosis and bradycardia). Tachypnoea with recession + nasal flaring may indicate either respiratory or cardiac disorders.

Question 23

What are the risk factors for the development of respiratory distress syndrome in neonates?

Answer 23

Pre - term delivery, diabetic mother, caesarean section without labour.

Question 24

What are the symptoms of RDS?

Answer 24

Tachypnoea, subcostal / intercostal recession and nasal flaring (which worsen after 60 hours) as well as ground glass appearance and bronchograms on X - ray.

Question 25

What is the treatment for RDS and what are the complications?

Answer 25

Mechanical ventilation and intensive care. 100 - 200mg of Surfactant (or 2.5 - 4.5 ml / kg) split into two daily doses and the administration of corticosteroids. The complications include: pneumothorax, bronchopulmonary dysplasia and intracerebral haemorrhage.

Question 26

Which bacteria are normally responsible for congenital pneumonia?

Answer 26

Group B streptococcus; E.coli, Haemophilus Influnenzae; Listeria monocytogenes; Enterococci and Staphylococcus aureus.

Question 27

How do you diagnose congenital pneumonia?

Answer 27

Infant presents with respiratory distress, meconium staining of the umbilical cord or skin and patchy inconsistent shadowing on X - ray.

Question 28

What are the major complications of meconium aspiration and how is it treated?

Answer 28

May cause pulmonary hypertension (–> reduced lung perfusion and hypoxaemia).

Treatment involves surfactant administration, high frequency oscillatory ventilation, administration of nitric oxide. Extracorporeal membrane oxygenation should be considered as a last resort.

Question 29

How do you treat congenital pneumonia?

Answer 29

Ampicillin: 30 - 50 mg/kg 12 hourly;
Ceftriaxone: 20 - 50 mg/kg daily;
Cefotaxime;
Gentamicin.

Question 30

What factors lead to the development and persistence of bronchopulmonary dysplasia?

Answer 30

Premature delivery; pre and post natal inflammation and infection, ventilation, oxygen and poor nutrition.

Question 31

What are the four heart defects seen in Tetralogy of Fallot?

Answer 31

1. Ventricular septal defect;
2. Pulmonary stenosis;
3. Enlargement of the aortic valve (sits on top of ventricular septal defect);
4. Right ventricular hypertrophy.

Question 32

What are the five main ways cardiac diseases present in neonates?

Answer 32

1. Cysanosis (lack of pulmonary blood flow);
2. Cardiorespratory distress (increased pulmonary blood flow);
3. Cyanosis and cardiorespiratory distress;
4. Shock syndrome (low cardiac output);
5. Asymptomatic murmur.