If you are rh negative, it means that you lack the D protein of the Rhesus system. There are actually many different blood systems that combine to give you your own specific type. The two systems that are considered to be most important are the ABO System, and the Rhesus System.
In the Rhesus System, there are currently 50 recognized blood antigens, and among which the 5 antigens D, C, c, E, and e are the most important ones. (wikipedia)
An ANTIGEN is simply anything that is recognized by your body as SELF or NOT SELF- or anything that can cause an immune response. The antigen that the medical community is referring to when they say someone is rh negative is the D antigen of the Rhesus System. You are rh D negative.
Are there health risks associated with being rh negative?
YES! There are definite health risks associated with being rh negative! First and foremost is blood type incompatibility. Everyone is susceptible to blood type incompatibility, but people who are rh negative have the strongest immune response against incompatible blood. (Of course the compared response depends on how much blood is exchanged.) The antibody response associated with the D antigen is considered to be one of the most aggressive immune responses. At one time, many babies died because the consequences of mixing blood types was not known.
What happens is, the rh negative body detects blood that is not it's own, specifically it senses the D antigen. An rh negative person does not have D antigens, so it responds with antibodies to fight off the invader. It's just like what your body does when it fights a cold, except the consequences of mixing rh negative blood with rh positive blood can be deadly. The D antibodies aggressively attack the "foreign" blood cells, wrapping themselves around the cells and essentially smothering them. That process is called hemolysis. A Hemolytic reaction, or Hemolytic disease can be dangerous in any situation, but it is particularly a concern in newborns.
When an rh negative woman is pregnant with an rh positive child, there could be a serious situation if there is any blood exchange. Unless a sensitizing event has occured, it's usually not a problem in a first pregnancy for a couple of reasons. First and foremost, most blood exchange happens during delivery. Some midwives believe that the medicalization of birth has a lot to do with that statistic. Episiotomy, damage to the placenta from pushing, the forced delivery of the afterbirth, and cutting the cord too soon are just a few of the factors that can cause a blood exchange in a delivery situation.
Another reason rh incompatibility is not usually considered a problem in a first pregnancy is that it's believed to be an initially slow response. It's the subsequent exposures that cause the quicker and most severe reactions.
In a blood transfusion, the same rules apply. If it's a very small amount, and the very first time, the reaction will be slight. But, it will be a reaction, so another exposure may cause a dangerous hemolytic reaction. It's best to always be transfused with your own blood that you have donated, or a matching type.
Should I wear a medical I.D. bracelet?
It is highly recommended that you have something that identifies your ABO type and rh negative status whether that be jewelry, a card for your purse or wallet, or stored in the I.C.E. (in case of emergency) section of your cell phone or mobile device. Some people have gotten tattoos. It's important that you be identified as having rh negative blood early on in an emergency situation.
Can two rh positives have an rh negative child?
Yes! Your rhesus status is determined by both of your parents through the donation of alleles or proteins which are the building blocks for genetic expression.
Everyone has two alleles that determines rhesus status because each parent gives you an allele. An allele can be positive or negative for the D antigen in the Rhesus System. The positive (D) allele is considered dominant, and the negative (d) allele is considered recessive.
If both parents had rh positive blood, but conceived an rh negative child, then they EACH carry the rh negative recessive allele. A recessive allele will only express itself if it is paired with another recessive allele. For example, you are rh negative so you are -/-. A person who is rh negative recessive would be -/+.
To illustrate this, refer to the following tables-
For more information about inheritance and blood type, please read the following articles on this network-
The Rh Blood Type System
Blood Types, Inheritance and Paternity
Can a persons blood type change?
YES. Although it is rare.
Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease. An example of this rare phenomenon is the case of Demi-Lee Brennan, an Australian citizen, whose blood group changed after a liver transplant. Another more common cause in blood-type change is a bone marrow transplant. Bone-marrow transplants are performed for many leukemias and lymphomas, among other diseases. If a person receives bone marrow from someone who is a different ABO type (e.g., a type A patient receives a type O bone marrow), the patient's blood type will eventually convert to the donor's type.
Also, a more common reason for a persons blood type to "change" is a mistake in the lab where the blood is being tested- and OR different protocol is used by the lab to determine blood type. For example, one lab may type a heterozygous (+/-) person as a positive, and the other lab will type the same person as a negative!
Can rh negatives get AIDS?
There has been a raging internet battle for years about whether rh negatives can get the AIDS virus or not. You're not going to find the answer to that question here, but I can say that certain blood types and factors of blood types DO AFFECT your health and immune system. So, it's not completely implausible that a certain part of the population may be immune to AIDs- we just don't know for certain who these people are yet.
The latest research seems to show that the HLA-B27 gene appears to be resistant to the AIDS virus. Most people who have this gene are rh negative... but not ALL rh negatives have the gene.
HERE is a great article that you can read about the HLA-B27 gene and the AIDS virus.
Does an rh negative have "alien" genes?
There are many websites out there exploring the concept that people who are rh negative are aliens, reptillians, hybrids etc. Some of those website will explicitly state that we are definitely reptilian. Usually the crux of their belief system surrounding this thought process is that rh negative women reject their offspring.
The problem with saying that we are aliens because of blood incompatibility is that everyone, regardless of rh status, is prone to the same situation. A person with type A+ blood cannot accept B+ blood regardless of if it came from a transfusion, or their own offspring! So, a pregnant woman with type A + or O+ blood had blood exchange with a type B+ fetus, there could very well be a hemolytic reaction! Granted, the Anti D antibodies of the Rhesus System are known for being particularly aggressive once stimulated, but blood type incompatibility is something that everyone should be concerned with, not just people with rh negative blood.
So, I guess if blood type incompatibility is the basis for the argument, then all humans are aliens.
Others say that we are aliens or hybrids because many of us seem to have "special" abilities. The most common abilities are~ empathic ability, electrical disturbance, and ESP. There needs to be more studies done on this. There is no scientific poll out there to answer this question. I have personally met rh positive people who have exhibited the above abilities, but are those rh positives heterozygous (+/-) or homozygous (+/+)? Until we actually study the phenomenon, all the talk about it is conjecture.
The fact is, no one knows for certain where rh negative blood comes from. Heck, we don't know where the different blood types come from either, nor do we know for sure how life was created on this earth. We're just guessing and hypothesizing about that stuff. There are a LOT of theories, but none have been proven beyond a shadow of a doubt. So, bottom line is- we don't know. Period.
Thanks to: http://rhnegativeblood.ning.com