| Question |
Answer |
| Hemolytic disease of the newborn is? |
destruction of RBCs of the fetus & neonate by AB produced by the mother |
| Th mother is stimulated to produce ABs by? |
curent or previous pregnancies or by transfusion |
| HDN is most commonly caused by |
anti-D and other Rh blood group ABs |
| During pregnancy there is fetomaternal hemorrhage |
which are RBCs from fetus enter the mothers circulation, 0.1ml |
| Mother forms antibodies against |
paternal antigens |
| IgG antibodies cross placenta |
and bind to fetal RBCs |
| D hemolytic disease |
caused by anti-D alone or in combo with anit-C or anti-E |
| Other hemolytic disease |
caused by other Rh ABs or blood group ABS, anti-K, anti-c |
| ABO hemolytic disease |
usually caused by anti-A,B in O women |
| FHM occurs in # of pregnancy |
75%, usually immediately after delivery |
| Other causes of FHM |
amniocentesis, abortion, chorionic villus sampling, cordocentesis,etopic preg, blunt trauma to abdomen |
| Since advent of Rh immune globulin |
< 1% of D neg mothers exhibit immunization |
| Incidence of 'D' HDN = |
18% in untreated D neg mothers of D pos infants |
| Prevalance of non-anti-D HDN = |
<0.3% |
| Transfusion of D pos red cell products |
to women of child bearing age should be avoided |
| IF D pos transfusion necessary |
then Rh IG prophylacic treatment |
| Hemolysis & Erythropoiesis |
Maternal IgG AB attaches on fetal RBCs; AB/AG complex removed by macrophages in spleen; fetal bone marrow & hempietic tissue in liver & spleen increase RBC production |
| Anemia |
moderate to severe depending on #RBCs destroyed; severe anemia may lead to hydrops fetalis from enlarged liver and spleen; |
| Anemia cont |
RBC destruction continues after birth as long as maternal AB in system |
| Hydrops fetalis |
severe edema, effusions, ascites |
| Bilirubnemia |
RBC lysis casuse release of HgB which is metabolized into indirect bikirubin; then may be transported across placenta & conjugated in maternal liver to direct bilirubin & then excreted |
| Bilirubnemia cont |
total bili elevated in fetal serum & amniotic fluid, but not harmful; after birth, accumulation of indirect bili to toxic levels & can cause brain damage |
Biology Lab Midterm
