The Rhogam Shot and Rh Negative Blood Type

by | September 17, 2017

What do you know about the Rhogam shot and Rh negative blood type?

rh negative blood type

A commonly shared desire amongst the vegan community is the avoidance of any type of unnecessary medical intervention. Vegans, and most people really, simply want to be all natural and ingest as little chemicals as possible. Internet sources will tell you numerous different things about the Rhogam shot and what it does for people with the Rh negative blood type. It is important to understand the biology behind the shot before making any decisions. You will want to know what the shot does to not only protect you but to also protect your future pregnancies. And while many vegans do want to avoid chemicals, this is one shot you may not want to pass on.

Your Body Loves Itself

All cells, including non-human ones like bacteria and viruses, have proteins on their cell wall surface. These proteins are collectively referred to as antigens. The human body is programmed in such a way that it knows and loves its own cells. It wants nothing more than to protect itself from harm. One of the ways our body protects itself as though the creation of antibodies with specificity to some antigens. This specificity is much like two matching puzzle pieces coming together, almost with a perfect fit. Exposure to an antigen occurs and its respective antibody is created by the immune system. Once an antibody binds to its target, it releases signals to other defense mechanisms. These signals are a request to come help clear out the foreign debris.

An amazingly unique ability of the cells that create antibodies is their ability to give some of them a memory. The basic biochemical mechanism behind vaccines is exposure of a person to a known foreign antigen. This exposure from the vaccination causes the initial immune response. The immune system then not only makes antibodies to that antigen, but it also makes antibodies with a memory to that antigen. This is what allows for long-term immunity to exist and act upon any further exposures to that same antigen. Memory antibodies have the ability to respond much faster and much stronger to an antigen upon subsequent exposure. This allows your body to fight off any secondary exposures at a much faster and far more powerful rate.



A Side Note…The Role of a Red Blood Cell

Red blood cells main job are to carry oxygen to the tissues of the body. Every cell and tissue in the body requires oxygen for their survival. Without oxygen, cells and tissues rapidly deteriorate and die. Signals an antibody releases to other cells in the body calls for the destruction of the target cell. Abnormal destruction of red blood cells causes something called hemolytic anemia. As hemolytic anemia worsens, it leads to very low oxygen levels in tissues and cells. Without intervention, those cells and tissues will begin to die at an alarming rate leading to possible lethal consequences.

Another potentially lethal side effect of hemolytic anemia is excess bilirubin. Broken red blood cells release the bilirubin that inside of them. Biochemical processes exist that repurpose the bilirubin to newly created red blood cells. Excess bilirubin occurs when the destruction of red blood cells occurs faster than the body’s ability to respond. When this abnormal destruction occurs in tissues as well as the bloodstream, the body is unable to keep up and overload occurs. High levels of bilirubin, which causes neonatal jaundice, can lead to irreversible brain damage.



So What is the Rh Factor?

Roughly 15% of the human population has Rh factor negative blood. Rh factor is actually an antigen called the D antigen. Being Rh positive indicates that the D antigen is present on the surface of red blood cells. Conversely, Rh negative means lack of the D antigen on the surface of these cells. Due to a lack of the D antigen, for a person with the Rh negative blood type, their immune system will consider the D antigen of a foreign body. As such, exposure to the D antigen will cause an immune response that includes the creation of anti-D antibodies. Creating these antibodies is something called sensitization to the D antigen. When someone becomes pregnant, prenatal testing includes testing for the Rh factor (blood typing) as well as testing for sensitization to it (antibody screening).

Why Does The Lack of Rh Factor Matter in Pregnancy?

Problematic are Rh negative people that are pregnant with an Rh-positive fetus. This has a ~50-100% chance of occurring if the other parent is Rh positive. A baby will receive one gene from each parent. Each parent has two genes. If one parent is Rh negative, the genes they possess are both negative. However, if a parent is Rh positive, they could either have two positive genes or one positive and one negative and can pass either one on to the baby.

The umbilical cord and the placenta support babies in utero. Through the placenta and umbilical cord, the baby receives important nutrients and oxygen. This mechanism is generally a one-way street. The parent providing the nutrients and then acting as a receptacle for the baby’s waste. Because of this, the parent is generally not exposed to the baby’s blood. If the baby is Rh positive and the parent has the Rh negative blood type, exposure to the fetal D antigen is something that ideally should be prevented.

Exposure to the fetal D antigen can occur due to abdominal trauma, amniocentesis, chorionic villus sampling, ectopic pregnancy, abnormal bleeding, abortion or miscarriage. Indeed, there are instances in which there is no explanation for exposure. If exposure does occur, it could cause the creation of the anti-D antibody and those rather troublesome memory antibodies. Upon subsequent pregnancy, those memory cells may be activated and launch an assault on the fetal D antigen. This immune response can lead to dangerous levels of hemolytic anemia in the baby. Mild to moderate cases generally cause a milder anemia. More severe cases may lead to intrauterine blood transfusion requirements and even lead to a stillbirth.



The Invention of Rhogam

Researchers set out to create a method to prevent an Rh negative parent from creating antibodies against the D antigen. This eventually led to the design of the Rhogam shot. The shot injects synthetic antibodies into the parent. These antibodies have a strong specificity for the D antigen. If fetal red blood cells have entered the parents’ bloodstream, these synthetic antibodies will bind to the D antigen that is present on them. This binding, called neutralization of the antigen, will hopefully prevent the immune response from occurring in the parent. Although exposure to the fetal red blood cells isn’t a sure thing, 28 weeks of gestation or later is usually when this may occur as the risk of exposure roughly 16%.

Once the baby is delivered, the lab will test the baby’s blood for the D antigen. Rh negative babies will indicate no further testing is necessary. It will be necessary for further testing of Rh positive babies in order to determine if the parent was exposed to the fetal blood. Exactly how much fetal blood that has been exposed to the parent will determine how many vials of Rhogam should be administered. Up to four vials of Rhogam may be needed in order to neutralize any D antigen. By giving the Rhogam injection during the seventh month of gestation and again within 72 hours after delivery (if the baby is positive), the risk of developing Rh antibodies becomes less than 0.1%.

A Rare But Important Note

One other item to touch on that is likely a rare but also important topic. Trauma situations often require the use of emergent blood. Hospitals have strict rules in place as to what type of blood they will use in an emergent situation. Determination of what type of blood is getting to someone emergently is based on sex and being past childbearing age. Having been previously sensitized to the D antigen and then receiving an Rh positive blood transfusion could prove to be problematic. This is especially true if your body has just been involved in a traumatic event. Just something to think about if you are seriously considering declining this shot.



Hmmm…So, Should I Get The Shot?

There will always be concerns in the Vegan community about medical intervention and the use of chemicals. Severe neonatal jaundice can and does cause irreversible brain damage and hemolytic anemia in an infant can be fatal, very quickly. The shot has proven to be incredibly safe and is now packaged and formulated without thimersol. While concerns over chemicals will likely ever go away, any possible consequence of not taking the shot seems to far outweigh any risks involved.

P.S. The shot is made from human proteins instead of animals, another bonus for us! It is also on the World Health Organization’s List of Essential Medicines.


Do you have a story about your Rhogam & Rh Negative experience?  Please share it with us!




2 Responses to “The Rhogam Shot and Rh Negative Blood Type”

  1. Humberto Polian
    March 11th, 2019 @ 9:12 pm

    Howdy! I just would like to give a huge thumbs up for the nice information you’ve got right here on this post. I can be coming back to your blog for extra soon.

  2. Irene
    June 27th, 2019 @ 5:05 pm

    Rhogam shot contains glycine, most likely derived from pork gelatin.

Leave a Comment