Question

Explain the following process (150words each) (5marks each) A) sensitisation of a D negative mother to a D positive fetus B) the movement of maternal anti D from the maternal circulation to fetal circulation C) D positive fetal cell destruction as a result of maternal derived anti D

Answer 1

A. Firstly, one need to understand

What is Rh sensitization?

=If blood mixed with Rh +ve blood, then immune system will react to a Rh factor by making antibodies to destroy it. This immune system response is known as Rh senitization.

Rh sensitization during pregnancy can only happen if a woman has Rh -ve blood and only if her baby has Rh +ve blood.

In case 1: Mother-Rh -ve

Father- Rh+ve

then there is a good chance for baby to have Rh +ve blood, and ultimately Rh senitization can occur.

In case 2: if both parents have Rh -ve blood, then baby will have Rh negative blood. Since, the mother's blood and ther baby's blood match, sensitization will not occur.

if you have Rh -ve blood, doctor will probably treat one as thoughthe baby's is Rh_ve no matter what the father's blood type, just to be on the safe side.

B. The Rh+ve RBC_s of the fetus can gain entry into Rh-ve maternal circulation through FMH(fetomaternal hemorrhage) which results into the formation of anti D antibodies, wehich pass to the fetus through placental circulation and can destroy fetal Red blood cells that produce fetal anemia.

C. In this condition of pregnancy, IgG is able to pass through the placenta into fetus, or if in condition the level is sufficient it will cause destruction of rhesus D+ve fetal RBC_s , which leads to the development of Rh disease. This further regarded as insufficient immune tolerance in pregnancy.