Blood type tests are fun and readily available on Amazon.com for less than $10 each! I suggest ordering one for an educational and interesting home experiment to determine your blood type and Rh factor. :)
Even though it was really fun, we ordered the test for an actual practical reason. We needed to check Chris's blood type. I'm Rh negative which occurs in about 15% of the population. This means that if Chris is positive, I have to get immunized against the Rh factor to prevent potential immunoincompatibility with the baby (who has a 50% chance of being positive). Rh incompatibility occurs if the baby is Rh positive and the mother is negative. Late in the pregancy or during delivery it is possible that some of the fetal blood cells can cross over into the mothers body, and sensitize her immune system to the Rh protein. This means that in subsequent pregnancies, if the baby is positive, the mothers immune system will attack the blood of the fetus and cause all sorts of problems. For example, miscarriages will be much more common, and if the fetus does manage to grow, there is a risk of anemia and neurological disorders/mental retardation (eek!). There are risks to having the immunization (inducing an immune response in the mother is generally something to be avoided), but the possible complications with subsequent pregnancies are so extreme that the benefits out weigh the minor disadvantages.
However, if Chris is negative, then I can avoid having the immunization because the baby will definetly be negative. So we ordered the Eldon blood typing kit from amazon. It consists of a blood type card, an alcohol swab for your finger, a lancet (i.e. finger poking device), 4 little spreaders for applying blood to the card and a chart to determine your type. The card has 4 circles on it. The first one has antibodies to blood antigen A, the next has anti- B, the next has Anti-D (or Rh), and the last is a control circle that has no specific antibodies on it. The first two circles tell you if you have A, B, AB, or O blood and the Anti-D circle tells you if you are Rh negative or positive. Basically, if you are positive for that antigen, your blood will react with the antibodies and get all clumpy, if you are negative, nothing will happen and the blood will just sit there.
This is what a test for A positive blood should look like. Note the clumpiness in the first Anti-A circle and clumpiness in the Anti-D circle. This is what Chris's blood type turned out to be.
This is what the actual test ended up looking like, much messier and grosser, but we could still figure out the blood type. Mine is on the left, I'm A postive and Rh negative. Chris's is on the right, he is indeed A positive and Rh positive (although this is quite hard to see in the picture). So, it turns out that I need to get the immunization. This wasn't too surprising since Chris had an 85% chance of being positive, but it was worth confirming it ourselves to be sure. And like I said above, very fun. Go science!
Your Grandmother Rita was A-, too and so is I believe, your Dad. There was no RhoGAM. Your Dad was A- so no immune response developed? However your grandparents were told not to have another child which, given Uncle Keith's arrival 11 months later, they ignored. I wonder if Uncle Keith was Rh + or - ?
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