I was thinking earlier today that I should do a post about what it means to have a negative blood type during pregnancy and what the rhogam shot does. I considered doing this post because it isn’t well known and it added to my confusion and grief during a traumatic time in my life. If only someone had taken the time to explain it to me back then! But you know what? Even people in the medical community don’t know what it’s all about! I majorly questioned the nurse who gave me the shot while I was miscarrying, but my questions went way beyond her scope of understanding to the point where she just said “I don’t know, I didn’t major in obstetrics.” I called the 1-800 Telehealth Ontario phone# and questioned them. The nurse there had to pull out her manual and could not answer my questions using all of the resources available to her. I asked my friend, a nursing student, who went through all of her nursing books as well as the medical sources available to her as a med student that aren’t available to the general public. My questions went beyond the answers. I have read up on it like crazy, as best I could. I feel like I know so much more about it than many people in the medical community and definitely more than the general public – who are completely oblivious to the issue, unless they have a negative blood type and have been pregnant before.
RH- blood does not like RH+ blood. If RH- blood comes in contact with enough RH+ blood, the RH- blood will begin producing antibodies to fight off the RH+ blood because it sees it as a foreign and dangerous invader. It is a natural response like an immunity response. If an RH- woman is pregnant with an RH- baby, everything is wonderful and honky dory. If both the mother and father are RH-, then the baby will also be RH-, however, doctors may very well treat the pregnancy with the assumption that the baby is RH+ anyway, on the chance that the mother may have been messing around, etc. The doctors don’t want to take the risk that the mother is lying or withholding information. If the father is RH+, there is a good chance the baby will be RH+ as well because RH- is a recessive gene, meaning usually the RH+ wins over the RH-. I could go into this more if you are interested, but like the docs will do, I will just assume the baby will be RH+. Better safe than sorry. When an RH- woman is pregnant with an RH+ baby, things become interesting. The first pregnancy is generally considered safe. During a healthy pregnancy, the RH- blood never meets up with the baby’s RH+ blood. It only happens if something goes wrong, and it happens during childbirth. Once the RH- blood meets with RH+ blood, it begins producing antibodies within the next 72 hours. These antibodies will continue to reproduce. Once the RH- blood begins producing the antibodies, there is no going back. The antibodies are there for life. As I said, the first pregnancy is generally safe. The antibodies are unlikely to damage the current baby that initiated the production of antibodies. The future pregnancies are the ones that are in danger. The antibodies can “attack” future babies who have RH+ blood types. There are different effects on a large spectrum. At it’s worst, the antibodies can kill a future baby. At it’s best, there are no effects to the future baby whatsoever. A common effect is jaundice. Jaundice is VERY common in new borns and is usually treatable. Unfortunately in the case of RH- antibodies induced jaundice, it could potentially be a very bad case of jaundice to the point where blood transfusions are necessary. I’ve even read of cases where blood transfusions were performed within the womb! (successfully). I hope you haven’t stopped reading yet because there is good news! And lots more good news then you have probably ever heard regarding this whole scary negative blood type thing!
First of all, there is the rhogam shot. Usually in the USA and Canada they give a rhogam shot at 21 weeks of pregnancy. This is because before that time, the risk of the RH- blood coming into contact with the RH+ before 21 weeks, is slim. As I said, unless something happens, the chances of the blood coming into contact during a healthy pregnancy is low. The rhogam shot puts antibodies into your blood stream letting the RH- blood know there is no need to produce antibodies, because they are already there (from the shot). The thing is though, the antibodies in the rhogam shot are basically duds. The antibodies in the rhogam will not harm your baby. After giving birth, the rhogam shot is given again within 72 hours (likely within 24 hours). If there is any sign of trauma within the pregnancy, the rhogam shot is given as a precaution. If there is a miscarriage or a threatened miscarriage, the rhogam shot is given. When it is an early miscarriage, the shot is given as a precaution. From what I have read, it is given during an early miscarriage based on the theory that the blood interacted. I have not read anything that demonstrated to me that an early miscarriage without the shot has actually caused the antibodies to begin production. This is good news because many early miscarriages aren’t even known to have taken place! It is actually pretty common for a woman to not know she is pregnant until she miscarries, or even when she does miscarry that early, she just thinks it’s an extra bad period.
When I miscarried the first time, I was only about 6.5 weeks. The hospital gave me the shot, as I explained. What I haven’t mentioned yet is that with this current miscarriage, my OBGYN did NOT give me the shot. I asked him about it, and he affirmed what I had concluded from my own research, that at such an early stage, the baby is MUCH too small to even have enough blood to interact with my blood. I don’t know how much blood needs to interact but it must be more than a tiny droplet or we would be more concerned about building up these antibodies through regular accidents you might come into contact with throughout your life (or through the old childhood practice of blood brothers/sisters). My OBGYN knew that the gestational sac was only 2mm in size, and he told me that it would not have enough material to it to cause an issue. After all of research I have done on my own, I was pleased with his response. And I did NOT get the rhogam shot this time around.
Don’t go away yet, I have more info!
After my first miscarriage, I asked my family doctor about my risks of not having got the shot soon enough or if the shot didn’t work, or if I should have got a second one after the miscarriage, etc. My family doc sent me for blood tests to tell us how much antibody was showing up in my blood. This was a month or two after the miscarriage and the shot at this point. The blood tests came back showing that there were antibodies in my blood. But there was no way to know if they were from the shot or if my body had produced them, so another blood test was necessary. The second test should have shown the level decreasing if the antibodies were just from the shot, not my own blood. Well, the number hadn’t changed at all. Months later I did the blood tests again and the antibodies were completely gone. So although it was weird the way they had stayed in my system, I know they did go away eventually so my RH- blood was still safe and clean from the scary antibodies.
So this mysterious rhogam shot… it has some controversy surrounding it. Up until a few years ago, it was common for the rhogam shot to have thermisol in it (aka, that mercury preservative that people are afraid of in the vaccines). Perhaps our adult bodies can handle that amount of thermisol, but can our little unborn babies handle that amount? That’s a fear out there. You have the right to ask for mercury free rhogam. From what I have read, for the last few years, the rhogam shots in the USA are mercury free. But it doesn’t hurt to ask anyway, if it is a concern for you. I haven’t found any info on whether Canada’s rhogam shots are mercury free. And I haven’t asked anyone in the medical field here. I will ask when the day comes again that I must face the rhogam shot in my butt. There are some stats out there that are really really scary. They relate the occurrence of autism in children born to an RH- mother who had the rhogam shot. Scary. Look into it yourself. Who knows how thorough the research was that put together those stats. I have read that in some European countries, they do not give the rhogam shot at all during pregnancy unless there is trauma that could increase the risks of blood interaction (such as a car accident). In those countries, they give the rhogam shot after delivery. Some people in North America request this as well.
What are the risks of blood interaction anyway? Slim during a healthy pregnancy. During delivery, you are almost guaranteed to have blood interaction. I think it is like 95% likely that the blood will interact during childbirth. That percent is a little lower in home births, however. This is due to it being a more relaxed environment at home then often found at the hospital. It isn’t low enough to convince me to forgo the shot, whether I did a home birth or not (although it is an argument for home birth…).