Rh Isoimmunization in Pregnancy

Question 1

What is Rh Isoimmunization?

Answer 1

A pregnant woman has developed antibodies to foreign red blood cells (RBCs), most commonly against those of her current or previous fetus(es), but also caused by transfu- sion of mismatched blood.

Question 2

Mention the risk factors.

Answer 2

Transplacental haemorrhage as in:
1- Abortion.
2- Ectopic Pregnancy.
3- Medical procedures: Amniocentesis, chorionic villous sampling.
4- Placenta previa.
5- Placenta abrptio.

Question 3

Mention a protective factor.

Answer 3

ABO incompatibility

Question 4

What are the prerequisite for development of isoimmunization?

Answer 4

1- Rh -ve mother.
2- Rh +ve father.
3- Presence of atypical ab
4- Ab associated with HDN
5- Ab titer > 1:8

Question 5

Investigation?

Answer 5

1- Amniocentesis (Lily’s Curve):
to check bilirubin concentration.
2- Fetal blood sampling (PUPS):
The most accurate but the most invasive procedure.
3- MCA-PSV:
The standard tool for prediction and determination of fetal anemia .. not invasive.

Question 6

Treatment?

Answer 6

if there is a severe anaemia detected by investigation the management will be:

• < 35 GA –> IUT
• > 35 GA –> Deliver