Rh Factor

[prsndwg]

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Can someone please explain this whole concepts and the erthroblastosis fetalis please..

 

[276640]

Ok, it's really simple actually... The Rh facgtor is just an antigen which may be present on the surface of RBC. If an individual is Rh+, then they possess the Rh antigen, and if an individual is Rh-, then they do NOT possess the Rh antigen. What happens in erthroblastosis is this... A Rh- woman can be sensitized by an Rh+ fetus if fetal RBC enter maternal circulation during birth. Therefore, she will now have the antibodies to Rh and recognize it as non-self. If she has another fetus with Rh+, the anti-Rh antibodies she developed with her previous pregnancy may cross the placenta and destroy the fetal RBC. So in summary, if a Rh- woman has an Rh+ fetus, that first fetus will be unaffected. However, if she develops the Rh antibody during this pregnancy, and she has another Rh+ fetus, erythroblastosis fetalis can occur and kill the fetus. Hope this helps!

 

[prsndwg]

Ok, it's really simple actually... The Rh facgtor is just an antigen which may be present on the surface of RBC. If an individual is Rh+, then they possess the Rh antigen, and if an individual is Rh-, then they do NOT possess the Rh antigen. What happens in erthroblastosis is this... A Rh- woman can be sensitized by an Rh+ fetus if fetal RBC enter maternal circulation during birth. Therefore, she will now have the antibodies to Rh and recognize it as non-self. If she has another fetus with Rh+, the anti-Rh antibodies she developed with her previous pregnancy may cross the placenta and destroy the fetal RBC. So in summary, if a Rh- woman has an Rh+ fetus, that first fetus will be unaffected. However, if she develops the Rh antibody during this pregnancy, and she has another Rh+ fetus, erythroblastosis fetalis can occur and kill the fetus. Hope this helps!

Thanks, but how does she get an Rh + fetus if she has a Rh-?

 

[txchexmex]

Thanks, but how does she get an Rh + fetus if she has a Rh-?

That means the father is Rh+

 

[dentene ice]

so you are saying that the clumping between the rh antibodies and the rh + kid skips a generation??

In simpler terms if mother is Rh - and father is Rh + and has an Rh + kid, the kid is in the clear...but 2 years down the line they have another kid and the new kid is Rh+, this new kid will be affected?

 

[276640]

Yup, that is the general jist of it! Sorry, I forgot to mention that the father would have to be Rh+ in my previous post (obviously for them to have a Rh+ baby).

 

[Streetwolf]

so you are saying that the clumping between the rh antibodies and the rh + kid skips a generation??

In simpler terms if mother is Rh - and father is Rh + and has an Rh + kid, the kid is in the clear...but 2 years down the line they have another kid and the new kid is Rh+, this new kid will be affected?

It doesn't "skip a generation". It just CAN'T happen with the first child because the mother WON'T have antibodies against Rh+ until the first child comes along. The antibodies probably won't be produced quickly enough to affect the first child. But they'll DEFINITELY be around to affect the second child. Just remember that the mother HAS to be Rh-. The first child that is Rh+ (even if it's a miscarriage or abortion) can lead to antibody formation. The second child and beyond that are Rh+ will be attacked by the antibodies if they cross the placenta.

 

[bearandmonkey]

Antigens are proteins on the surface of cells that help the immune system differentiate self from nonself.The Rh Factor is an antigen.It is important to note that the Rh antigen is an autosomal dominant trait.If an individual has the Rh antigen he is considered Rh positive if not Rh negative.If R is dominant over r than RR and Rr yield Rh positive and rr yields Rh negative.

A woman that is Rh negative (rr) maybe susceptible to having a child with Erythroblastosis Fetalis (EB) provided the father is RR or Rr.However because fetal circulation never mixes with maternal circulation this incompatibility will not manifest itself in the womb.EB becomes an issue during a vaginal deliverywhen the blood of the fetus mixes with the blood of the mother.If mom is Rh negative and the baby is Rh positive than the mothers immune system will recognize the foreign antigen from the newborn and begin to produce Rh antibodies in her body.These Rh antibodies are of the IgG type which are the only ones capable of crossing through the placenta.Thus if mom has another baby that is Rh positive these Rh antibodies will begin attacking the second babies erythrocytes resulting in the EB.Therefore EB is only an issue potentially affecting Rh positive babies if the a woman is Rh negative and dad is Rh positive.Again the first child is never affected by EB even if the aforementioned conditions are met.Sensitization during vaginal delivery must occur before its an issue.

Rhogam and immunosuppressive therapy is usually given to women who may be having EB children thus woman nowadays have nothng to worry about provided they see their obstetrician early in their pregnancy.

Hope this helps.