From here:
An evolutionary oddity
Nobody knows why Rh-negative blood is as common as it is. It doesn’t produce any obvious advantage in people who have it but it can create a disease called hemolytic disease in the fetus and newborns. That can happen when the mother has rh-negative blood, the baby in her womb has rh-positive blood, and the mother previously had a baby with Rh-positive blood.
Because babies with hemolytic disease can die, natural selection ought to cause Rh-negative genes to become less common and eventually disappear. But that hasn’t happened and no one knows why.
I am a B Rh Neg male. I do not see any significant evolutionary advantage or disadvantage to that .
I am very content with the scientific reality that my Rh neg. condition is a consequence of a gene deletion many centuries ago. I am very intrigued by the (statistically) skewed distribution of Rh negs.
It is not trivial to explain that, since there are so many known and valid explanations for demographic phenomena. Much of the Rh neg focus has (understandably and reasonably) been focused on HDN and blood transfusion issues since they are practical clinical issues. I see the recent advances in inheritance genetics (non Mendelian genomics) as making it possible to get some kind of handle on the demographic issue. My daughter-in-law ( strange random chance) is also Rh neg, and had one child (and could have no more.) She and I think that the mother’s biology may “learn” from the bad experience of reverse polarity. that Rhogam now makes a safe birth possible, but that the mother’s body may then be inhibited from having more children. If true, that would be a partial explanation for some of the Rh Neg demographics.
I have RH- and with my second child I almost died at age 31years from Heart failure, the antibodies attacked my heart thinking it was a intruder, I had congestive heart failure after giving birth, my heart was pumping at 30%. they gave me very little hope, today my heart is at 85% and I live a good my life, work out eat heathy my daughter will be 23 this year.
Thanks
Paula McNeil