Parent/fetal blood types and antibodies: better see the text for clarification?

Question

(BLUSHING BIGTIME---help me out, please!) Fell asleep at a BAD time in nursing school and never took to maternity/child care anyway.... (and brain is NOT processing Google very well today)

Woman is type A blood; becomes pregnant by type B male. (Assume both Rh+, to keep it easy.) What blood types could the fetus be?

And why DOESN'T a woman develop the equivalent of antibodies to the "foreign" blood of the fetus (I assume)? With Rh incompatibility, you'd better give RHOgam or comparable, or you get increased fetal losses with each pregnancy, IIRC..... but how can a woman with one blood type successively AND SUCCESSFULLY bear living children to an "incompatible" father with different type? The placenta can't be THAT effective a barrier, can it?

Need a quick and relatively simple answer (or link) timely, pls---am digging thru refs now, but help MUCH appreciated!

It's not Rh incompat and RHOgam that's knocking me for a very confused loop---it's why a blood-type A female (for example) can repeatedly give birth to blood-type B neonates, without developing some sort of antibody problem SIMILAR to that seen in Rh disease.... (if that makes it any clearer)

Answer 1

From this information alone the offspring could be A, B, AB, O and either Rh positive or negative. It all depends upon whether the A is homozygous, AA or heterozygous, AO. Same for the B and the Rh+ could be either homozygous or heterozygous.

As for the antibodies. The dangerous ones are the IgG antibodies which the mother developes after being exposed to the foreign baby antigens at birth or after some other exposure like a placental tear, Baby blood does not cross the placental barrier easily. IgG antibodies developed at any time may cross the placenta in subsequent pregnancies, bind to the fetal RBC's if they have the correct antigen and cause them to be destroyed.

Our immune system does not form antibodies to everything we're exposed to. Also, so antibodies formed are IgA or IgM and too large generally, to cross the placenta.

Answer 2

in my opinion.. the difference between antigen Rhesus and the usual A and B antigens present on the blood cell mambrane is that the former induces ACTIVATION of immune sytem while the latter doesnt. Sensitization to Rh antigens (usually by feto-maternal transfusion during pregnancy) may lead to the production IgG anti-Rh antibodies which CAN pass through the placenta.

in the case where the mom blood and the fetus blood are incompatible (mom-A fetus-B) there isnt enough antibody from the mom to cross the placenta to cause any damage.

mom A dad B = fetus A B Ab or O

Answer 3

1. A, B, AB
2. Why women get none of foreign blood- Baby only gets mothers immune system, not the father's. It's not like the baby gets the women blood, just it's nutrients, and the immune system is all the white blood cells, not RBC's.
3. The Placenta is that good of a barrier- It's is even hard for the aids virus to get by the placenta, many times a c-section is done and the baby won't get aids.
Don't mix up the circulatory system and the immune system- they are very different- especially during pregnancy.

Answer 4

I have experienced this with all five of the births of my children. I received the injection of Rhogam after every live birth as I am Rh-. They also do this for still births and I believe miscarriages (not sure on this one though, I'm not professed on maternity nursing) There are some simplified articles listed here. I am a 20+ year veteran of nursing and I know how some of those theory days can "slip by" when sleep takes over.

http://www.justeves.com/ipl/rh_factor.shtml

http://sln.fi.edu/biosci/blood/rh.html

Good luck to you my friend and great luck in your career.
sbj

Answer 5

if the female is Rh negative and the fetus is Rh positive she gets a shot that supresses her immune response.

Answer 6

A+ B+ or AB+