Hemolytic disease of the Newborn

Hello there,

My name is Staph and today we will be learning how to twerk.

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Can you write a single post without getting grilled by me -_-

Na, absolutely not. Anyways today we will be learning about monkeys and their effects on our lives. And monkeys do twerk, so it's somewhat related to the post ;p

Back to the subject

I know many of you might be knowing about Rh blood group inherited by our ancestral recess monkeys.

Jesus! It's Rhesus. Rhesus monkeys.

Sorry, it's recess time when I am writing my post. Kinda hungry.

Off topic.

So Rh blood group is considered to be second most important after ABO. Talking about the disease, HDN occurs when the mother is Rh negative and the fetus is Rh positive.

Let's look at it in detail.

There is a mother who is Rh negative, carrying a fetus who is Rh positive. Fetal blood cells rarely gets into the blood circulation system of the mother. But chances increase during delivery. This is when the fetal blood cells gain entry into mother's system. Due to this, the mother gets sensitized and produces antibodies against the Rh blood cells. As this sensitization occurs after the delivery, the first child is born without any harm. Difficulties occurs during the second and the subsequent pregnancies. Rh antibodies have structure similar to Ig antibodies and hence they are incomplete antibodies. Therefore, it can pass from mother to fetus by crossing the placental membrane and damage it's erythrocytes.

The clinical features can very from severe jaundice in the newborn to erythroblastosis fetalis or intrauterine death. Though the HDN is very harmful disease, it's occurrence is very less than expected.

 There are some factors that influence the incidence of hemolytic disease due to the Rh incompatibility. They are as follows:

1. Immunological unresponsiveness to the Rh antigen: I guess it's pretty clear by the name. Some individuals are nonresponders and never respond to the Rh antigens even after getting eposed to it. So they never generate antibodies against it and hence the fetus is not harmed.
2. Fetomaternal ABO incompatibility: So as iron cuts iron and poison kills poison, here incompatibility nullifies incompatibility. If the mother and fetus have ABO incompatibility, the Rh incompatibility becomes ineffective. This is because the fetal cells entering the maternal circulation are destroyed rapidly by the ABO antibodies before they can induce Rh antibodies.
3. Number of Pregnancies: Number of pregnacy matters, because the first child mostly escapes the harmful effects. The risk to infant occurs with the successive pregnancies.
4. Zygosity of the father: An individual can be homozygous or heterozygous with respect to the D antigen. If the father is homozygous all his children will be Rh positive, whereas if he is heterozygous only half of his children will be Rh positive.

I hope this explanation helps you all.

Lots of love and a high six.

-Staph :D