Type O Negative Blood

April 8th, 2009

I have type O negative blood. I really gave this little thought up until yesterday when my mother and I started talking about blood type. I told her I was O negative and she remembered something about the negative Rh factor. My eyes glazed over. Rh? Huh? Antigens who? Uncle what?

So last night I started digging around on google (I KNOW!) and discovered all sorts of weird stuff about my O negative blood type and how seemingly incompatible and uppity it is. 

Here’s the breakdown of ABO and Rh blood type by nation. 


And here’s a laymen’s understanding of my blood type:

  • I am a universal donor. Anyone can use my blood but I can’t use any other blood type except for my own.
  • I’m recessive. (Yeah, yeah. I get that a lot.) 
  • Two O positive blood carriers can have O negative offspring. (My brothers and I are proof of this.)
  • O negative blood carriers cannot take any other blood type because they lack the antigens involved and will therefore fight with it. Or something. (Someone smart needs to mom it down for me.)

Can two O negatives make an O positive? Is that even impossible? Also, are all the negatives eventually going to die off? It appears that way, right? Were there more at one point in time? I need a crash course on blood types. I’m so intrigued. 

But I digress. As I was searching and reading and learning about Rh factors and whatnot, I discovered a corner of the Internet dedicated to second and third pregnancies and O negative blood types. Here’s where things get a little wacky. If an O negative woman has a baby with an O positive man, and the baby is O positive, the woman can develop a problem. And since positive blood types are the dominant ones, there’s a good chance the baby will end up positive. A first pregnancy is usually not a problem because the woman most likely hasn’t come into contact with the antigen before. However, during birth, blood types often mingle, causing the O negative carrier to come in contact with the O positive blood type. The O negative person starts to fight said blood type—treat it as a problem, a foreign body. So, any future pregnancies can result in big problems.

The hell is that about? And why didn’t anyone tell me?

Naturally, I’m prematurely freaking out here and my husband is ready to cancel our Internet access. We don’t yet know Toby’s blood type because we weren’t required to have one before we were married. And I am not yet sure of Em’s blood type either. Maybe we’re super rare and all of us are negative? But I’m not holding my breath on that one.  (Emory is O positive.)

And I’m assuming my doctors had this in mind throughout my pregnancy and the moment Em was born. (Apparently there are shots mothers are given if the blood is mixed so they don’t develop these antibiotics. Look at me try and pretend I have the slightest idea what it is I’m talking about here.) At least I hope they knew about this. They are incredible, after all.

One thing is for sure, someone should take away my Internet connection.

Edited to add: I feel like such a moron. I’m actually O positive. I just called my doctor to find out why they didn’t give me this shot, ready to lose my mind about it, and she proceeds to tell me that I’m actually O positive. (My brothers, however, are negative.) I feel like the biggest O positive idiot ever. 

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95 Comments on “Type O Negative Blood”

  1. Cathy said at 9:57 am on April 8th, 2009:

    I’m so surprised to hear that your ob/gyn didn’t do anything to check your husband’s blood type. My ob INSISTED that my husband have his blood typed; his telling them was not enough. I’m O- and my husband is A- so there was no need to have the Rh injection which they need to during pregnancy by the 28th week and immediately after delivery. http://www.mayoclinic.com/health/rh-factor/AN00566

  2. Andre said at 10:30 am on April 8th, 2009:

    Actually this is only a problem in rare cases where the placental barrier is not fully functional thus permitting contact between the mother and fetal blood. This is a very rare occurence, as evidenced by the fact that we see different blood types within the same populations. Don’t forget, our genes have evolved during a long period where we did not have access to modern medical facilities and mothers would have many more than 2 children.

    To prevent such complications, the mother will be injected with anti-idiotype antibodies that specifically target her anti-rhesus Ab.

  3. Bobbi said at 10:43 am on April 8th, 2009:

    Long time reader, first time poster! ;)

    My mother is type O-. My father is type B+. My (younger) sister and I are both type B+.

    My mother had the Rh shot for both babies. Everything at birth for both my sister and I turned out fine… My mother had more things to worry about than the Rh factor. She vaginally delivered both of us and we were both TEN POUNDS. Yes, both her babies were 10 pounds. My mother is a saint.

  4. Milissa said at 11:19 am on April 8th, 2009:

    Really glad you posted the edit at the bottom because I was about to get really, really angry with you.

    You see, I am O- and my husband is O+, so I had to have 80 billion shots to make sure I wouldn’t die (I could be exaggerating in that last bit, slightly). I had to make special trips to the doctor to get shots, and then I had more shots in the hospital, and on and on. No one would stop talking to me about it. I had to show my special, handy-dandy Rh shot card to everyone. Constantly.

    So imagine my outrage when you tell us that you didn’t have to deal with any of that particular brand of crap! But I can now spare you my anger, seeing as how you’re actually a +. Not that I’m not jealous of you being a +. Because I am.

  5. Lana said at 11:20 am on April 8th, 2009:

    I’m an O+ too. The hubby had a surprise blood sample taken on our first trip to the doctor to see if he was a + too. Luckily he was so we didn’t have to do the shots.

  6. erica said at 11:40 am on April 8th, 2009:

    Not sure how true this is, but I have heard that the blood type issue is why Anne Boleyn kept having miscarriages after she gave Henry VIII their first daughter. Or maybe this was just in The Other Boleyn Girl.

    This also happened to Elissa Wall, who was one of the women who escaped from the fundamentalist Mormons. She had many many miscarriages with the man they forced her to marry because they didn’t allow her to see a doctor. I know this because I read her memoir.

  7. mihow said at 11:47 am on April 8th, 2009:

    That’s the thing, Erica. That’s where my head went. I wonder how common this was. Back before medicine got to be where it is today, I bet blood mingling happened more often. (Troubled births, etc) So it’s conceivable that babies and/or mothers would have died from it. Or mothers who are O negative were unable to have more than one child. (Is this why the numbers are so much smaller?)

    I guess even though I feel like an idiot, I did learn something new. So there’s that.

  8. Stacia said at 11:58 am on April 8th, 2009:

    It’s really any blood type that’s negative… not just O-. I’m B- and my husband is A+ (he did not have to get his blood checked we only know that from his mom) but since I’m B neg the doctors didn’t really care what my husband was, regardless I had the get the shot. At like 28 weeks I think? And then if the baby tests as a blood type positive then you get another shot while you are in the hospital. In my case my daughter is A- so since she’s negative like me I didn’t need another shot. BUT the shots are for the health of future babies. Say she was positive and our blood mixed in the delivery. My blood would build an antigen (i think is what it’s called) and any future pregnancies my body would fight off because of this antigen my blood built up from the first baby. The shots prevent that antigen from building up in my blood. Very technical, I know… it’s how my doc explained it to me.

  9. Somer said at 12:26 pm on April 8th, 2009:

    It was a good chuckle, at least after you found out you’re actually O+. I am A- so I had to have the rhogam shot before my son as born. After he was born and they discovered he was A+, I got another shot..which I don’t remember because I was sky high on morphine from the C-section. I know in later pregnancies I just have to suffer through another little shot in the butt and after the baby is born. Nothing big.

  10. Wendy said at 12:39 pm on April 8th, 2009:

    I knew I was O, but not sure about + or -, so they blood typed me as soon as I found out I was preg last time. Luckily for me, I am O+, so my husband never had to be typed. We are not even sure what type he is??

    It’s weird, as both my parents and sisters are A+, and have green eyes, but I am O+ and have brown eyes.
    Genetics are funny! However…it seems both my grandfathers were O/brown too, and I do look a LOT like my father, so I’m pretty sure I’m not from the mailman!

  11. mj said at 12:46 pm on April 8th, 2009:

    Eek. I don’t think I knew about this. I’m O- and so is my mom, but my pop is O+. Both of my older brothers are O+, but I don’t think my mom had major mega problems with her pregnancy with my middle brother.

  12. Mary@Holy Mackerel said at 1:00 pm on April 8th, 2009:

    Yikes! That’s a scare you’d rather not have had, I bet.

    I remember going through that rigamarole when pregnant. I’m O+, but hubby is A- or something like that. Both kids are O+ though.

    Such fun, eh?

  13. Brenda said at 3:38 pm on April 8th, 2009:

    I was one of what they called Rhesus babies. I am the youngest of 3 kids, and there were no problems with my brother and sister, but when I was born I almost died and needed a transfusion. The fact that they christened me first in the hospital and then later in church, seeing as how I survived and all, is my only claim to fame in my family. Mind you, this is going back to 1965, eons ago, so presumably things (medical know-how/can-do) have moved on since then.

  14. Thérèse said at 4:06 pm on April 8th, 2009:

    This is my first time here (came via dooce), and I would like you to know that I kind of love you a little for leaving this post up, despite its conclusion in red.

  15. jenB said at 4:34 pm on April 8th, 2009:

    I think you are awesome. Charlotte was in the NICU for 10 days because her blood type wasn’t the same as mine and she was severely jaundiced and all hating on my blood type. I cannot remember what blood type EITHER of us are now. Forgot. My husband probably remembers. 10 days NICU, I am a dork.

  16. Pascha said at 6:07 pm on April 8th, 2009:

    I was confused reading your post thinking, “Her doctor is an idiot for not giving her the rhogam injections.” Then I got to the part you added and felt relieved that your doctor is not an idiot after all. :)

    I am type AB+, meaning I’m a universal recipient. If I ever needed it, I can receive any type of blood. Is it weird that I consider myself lucky because of that?

  17. Sarah S said at 8:44 pm on April 8th, 2009:

    Oh my! I’m O Negative! I haven’t had a baby yet….but I don’t even know what blood type my fiance is. I don’t want to go through a bunch of shots!!! I’m going to go ask him what he is now.

  18. Judy said at 9:30 pm on April 8th, 2009:

    My father is O- and was born in the 1940′s, he had to have a transfussion at birth and his mother sadly died the next day. Modern medicence is a miracle! Loving reading all the stories!

  19. Kerry said at 10:49 pm on April 8th, 2009:

    I just read this and blood types completely intrigue me too. So funny that you are not the blood type you thought!
    I’m B- and have had soooo many of “those special shots” it’s not even funny! 3 babies and two of them I had spotting so I had to have a freaking shot for that too. And 2 amnios. One at 26 weeks and then after the birth. Because all my babies are B+. Fun times. That’s 10 shots….did I mention it goes in the bum fat??!!??
    Rh factors suck.

  20. Karen Sugarpants said at 11:17 pm on April 8th, 2009:

    I’m O negative and got the shot in the ass, both times. Believe me, you didn’t miss much. Want me to pinch ya? :)

  21. Sammie said at 11:47 am on April 9th, 2009:

    Just thought I would clarify for you, in genetics two recessive parents (i.e. negative) cannot make a dominant (positive) child. Sorry it’s a bit off the subject, but hey its good to learn something new everyday.

  22. mihow said at 11:51 am on April 9th, 2009:

    Sammie: Thanks! This stuff is clearly outside of my jurisdiction, but I do so love to mingle a bit with it from time to time. It does make my head spin though.

    Sarah S: Believe me, darlin’ when you’re pregnant, getting a shot or two will be the last thing you concern yourself with. :]

  23. Sarah S said at 4:02 pm on April 9th, 2009:


    I’m glad I read this. I will have to refer back to it later when I am preggers. :)

  24. Jessica said at 4:03 pm on April 10th, 2009:

    I had to laugh a little when I read this. I work in a laboratory and know all kinds of fun stuff about blood, which annoyed my OB to no end, I’m pretty sure. Anyway, I’m O neg, and so is my husband. My doc told me I should have the shot anyway. I told him no, and gave him my husband’s blood donor card, showing his blood type. He didn’t EXACTLY question my baby’s parentage, but did say that if I wasn’t 100% percent sure that the baby’s dad was my husband, I should really get Rhogam. I refused again. My baby is O neg. Not surprised!

  25. Marinka said at 8:29 am on April 12th, 2009:

    Nothing makes me happier than being able to one-up someone! I am AB-. Which means that at any given moment there are people hunting for my blood, because it is so rare and precious.

    And yes, I’ve been Rhogamed a lot.

    I’m laughing at your update, though.

  26. Rosanna said at 5:47 am on April 20th, 2009:

    I had four children and am O-. I found out of course with my first. She was born O+ and so I was given the Rhogam shot at 28 weeks and at birth. My second pregnancy, my daughter was born A- but they still gave me the shot at 28 weeks and at birth.. the last two kids are both O- so I only got the shot at 28 weeks for both and not at birth. I was tested prior to getting the shot to see if there were antigens in my blood and there were thanks to my first and was given the shot. It really is nothing. At that point in the pregnancy, it is like a pinch in the ass!

  27. Lily said at 10:43 am on May 13th, 2009:

    Have 3 children, my husband is B positive, I am A positive.
    Is it posible that our son is O negative?

  28. patricia courtney said at 5:46 pm on May 27th, 2009:

    a friend of mine is curious abot how it is, that both her parents are o neg. and that she is o neg. as well,ok here is the thing she has been told her dad is not her dad, so can two o negs, make an o neg. baby can any one answer this…

  29. cristina said at 11:52 am on May 28th, 2009:

    I have a daughter, and I don’t know what type of blood she is. I am O+ and her father is O negative, it’s possible our daughter is O+ ?

  30. noreen said at 2:12 am on May 30th, 2009:

    im 0- and my live-in partner is 0+ and were now on our 8months were both ready to have a baby but tell now im not preggy. im always on delays but never been pregnant. is there any possibility for me to get pregnant?

  31. Sammie said at 8:50 pm on May 30th, 2009:

    Lily, overall it is possible that your son is O negative but it’s quite a small chance. Without blood typing I can only say that he could be all blood types and all rhesus factors.

    Patricia, two O- parents can only make an O- baby. No other combination is possible.

    Cristina, yes your child could be O+ but she could also be O- too.

    I hope this is of help to you all. For anyone else who is worried I have found the website below which allows you to enter the blood type of parents and it will give you the possible blood types of the child. I havn’t had time to take a proper look at it, but it seems ok after a few tries.


  32. Wanda said at 9:30 am on June 12th, 2009:

    I have B-neg. blood type………I had to have the rho-gram shot. (yes, shot they only gave one in the 70′s when my daughters were born) My husband is A-positive, Our first daughter is also A-pos. Our second daughter is AB-neg. Our third daughter is A-pos. I had to have the shot after the first and 3rd. child back then, but not after the middle daughter because she was also neg.
    Anyone that is worried about their blood type being neg. and husbands being positive, just make sure you have the rho-grams shots and all will be fine. I did not have any problems with any of my 3 pregnancies………and Good Luck to all that are expecting!!!!

  33. Rhonda said at 1:11 pm on June 23rd, 2009:

    Patricia, positive is dominant factor. If you are o- and hubby is o+ most likely your little one is o+ also

  34. Rhonda said at 1:13 pm on June 23rd, 2009:

    I am A+ and my daughter is o-. We don’t see her dad so I am wondering what his blood type would have to be. He would most likely be – any suggestions?

  35. Mai said at 10:39 pm on June 23rd, 2009:

    Enjoyed the commentary. My question: can parents with 0+ blood (mother) and B+ (father) have an offspring with 0-?

  36. Melanie Byrne said at 6:26 pm on July 5th, 2009:

    If father is O Positive, and Mother is O Negative, which will child be? O positive, because of the father? Or can the child be O negative like the Mother? Please help! I’m going crazy here!

  37. 11:11 said at 12:29 am on July 11th, 2009:

    The Rh factor gets way more interesting…

    Does anyone know what rh stands for? It’s rhesus factor…as in monkey. All primates, including humans are linked by a protein in the blood.. except rh neg people. It is thought to be a mutation. My question is mutation away from, or towards what!?

    There are many other interesting qualities about rh neg blood. To me it is so surprising that it has even survived this long. (O being the original “pure” blood).

    I would love to see the scientific or even New Age community do some research into the origin and evolution of this bloodtype.
    If there is no link to primates (the basis of Darwin’s theory of evolution) could it be possible O- came from an entirely different species?

    Another interesting thing….I read the shroud of Turan’s blood was tested- Jesus was A-.

  38. reneeisonegative said at 5:01 am on July 14th, 2009:

    I’m O- Negative and have 3 children, all positive, their father was positive so I feel it is the dominate. There is a debate as to whether you need a rhogam shot at 28 weeks, if you are 100% sure that your baby has negative blood also. Then there would be no reason for the rhogam shot. The absolutely most important shot is the one you get after the baby’s birth because it protects the next baby. Especially if you have a different mate, this new man could have positive blood, that is why you need the Rhogam shot after your baby is born, after a miscarriage, abortion, anything like that. I have a myspace site with my name, go there for much more information. Even babies who have had the Rhogam shot can have a high bilirubin count, so even if they do not look jaundiced (yellow) I would have the bilirubin checked at least once after leaving the hospital, about 2 days later. A condition called Kernicterus can happen if the bilirubin count is too high it will cause brain damage. Go to my myspace page to see more. Also, have the Rhogam shot at 28 weeks if there is any doubt that your baby could have positive blood. When a negative blood woman becomes pregnant, her body sees the positive blood in the baby as an intruder and tries to expel it by releasing antibodies, a negative womans body sees it as a foreign substance and tries to naturally abort it. You need a good doctor, and if you’re poor and going to a clinic, do your own research and make sure they are treating you properly. I have found that poor people are the ones in today’s society that are mostly affected. Some free clinics don’t even blood type the mother!!! If you want to know your blood type for free, go donate at the Red Cross and they will give you a card with it on. Best of luck to all. Sincerely, Renee’

  39. Beccah said at 5:32 pm on July 19th, 2009:

    I don’t really have a reply but does anyone know if there is any risk in having children when both the father and mother are O negative?

    I have been looking everywhere and all I’ve seen is where the woman is O negative and the man is O positive…

  40. yasmara said at 3:03 pm on July 23rd, 2009:

    Another AB- here! I had the Rhogam shot w/both my babies (both boys, both B+).

    Beccah, there’s no risk at all if the parents have the same (negative) type – the only type your baby can be with 2 O- parents is O-. Some dr’s are concerned that the identified father isn’t really the father, so that’s why they may still advocate the rhogam shot as a precaution (imo).

  41. Paula said at 7:08 pm on August 4th, 2009:

    I’m ancient….daughters are in their mid to late 20s…and I was an “older” mother. I am O negative…so nice to be a universal donor, but can only get the same in return. When my oldest was born, home nurse had to come and give her a Vitamin K shot….I also kinda remember getting a shot after she was born in case I got pregnant again. Don’t even know the blood types of my daughters, but I’m guessing in the A category, since my husband is…does it matter if you know your blood type since it will always be typed when you’re donating or in an emergency situation.

  42. Stewart said at 9:45 am on August 20th, 2009:

    Can 2 O Neg parents have an A neg baby?

  43. Mina said at 4:07 am on August 23rd, 2009:

    You are very lucky, I have O Negative blood type. I have known my blood type my whole life, I was 18 when I became pregnant with my one and only child. The doctor the HMO assigned to me was a complete idiot. They NEVER asked me my blood type or my husbands…nor did they ever type my blood because if they had they would have given me the shots.

    Well this doctor was fresh out of her internship, I didn’t find that out until later. Her partner should have never left her to practice alone. She almost cost me and my child our lives due to her negligence. She did not check to see if my pelvis was correct for a vaginal birth (turns out I cant deliver naturally). She made me push for 5 hours, then when we were both in such distress her partner decided to check on my condition. After checking my pelvis he took her into the hall and yelled at her. He came in and said I had to have a c-section NOW. They pulled out the epidural because our blood pressures dropped so low. I had a C-section with no pain medication AT ALL. If her partner had not stepped in, we both would have died. A week later I was still in the hospital and she was gone from the practice. Moved to another state where I could not sue her. Since we both made it thru okay I gave up on making her pay for the most horrible moment of agonizing pain that any person could possibly suffer. I was flayed and disemboweled, with no anesthetic until after the delivery. Over 15 minutes of agony, and months of recovery. I have Fibromyalgia now [chronic overactive pain response] due to that trauma.

    But I felt lucky since we both made it thru. She is perfect in every way. No harm done. Only 5 pounds at birth, so really vaginal should have been no problem. Except my doctor was a moron, because every gyno since then has confirmed that my bones will not allow natural delivery.

    But really of all the things that went wrong, I find out another thing was overlooked…my blood type. I had tried several times to have another baby but i kept miscarrying. I only have my one child. If it weren’t for my daughter surviving that fubar delivery I would have never had a child.

    So don’t believe their lies, I wish i had known 17 years ago that my blood type made a difference. I was robbed of unborn children…all you have to do is take a home blood type test and you will know for sure. Order it its called an eldon card kit.

  44. Thayssa said at 7:40 pm on September 3rd, 2009:

    I’m getting kind of freaked with the whole O- thing just like you did. I am O- (‘m sure) and it worries me because the one other prson in my family that is also O- is my Uncle and he has AIDS so he can’t help me if something where to happen (God forbid). Also the fact that i have to be aware of what my future husband’s blood type is, is just kind of scary….to think that i could have problems with my pregnancy (when i am pregnant..which hopefully isn’t happening anytime soon due to the fact that i’m only 16). It’s just something that’s hard to think about…

  45. Mama Kalila said at 11:30 pm on September 4th, 2009:

    Haven’t read through all the comments but I keep seeing a common theme in some of them that I need to correct. Rh neg moms are not at risk by developing the antibodies… We can live with them/doesn’t kill us or hurt us in any way… Its our future children that it puts at risk.

    I am B neg… my husband is either A pos or AB pos… I have a A pos daughter… Been through all the shots and get to get tested soon to make sure I don’t have any antibodies still… if I do they’re gonna watch my pg extra close. Hopefully I don’t :-)

    Also to Thayssa, nothing will happen to your first pg. If you get antibodies during this one (and they will give you shots both before and after birth to try to prevent that) then something can in a future pg. Try not to worry about it.

  46. Adeoye Adewale Akeem said at 6:55 am on September 10th, 2009:

    Please help!! My wife is O- and I am A+. She got Anti-D injection after her first delivery to prevent any future problem for the next child.
    The 2nd child was delivered in a mid-wifery’s house and there was no Anti-D injection given to her to prevent future problem for the next child. This 2nd child is more than 1 year now.
    What can we do to avoid future Problem on the next child to come later.

  47. Lori Haave said at 11:00 am on October 4th, 2009:

    i have type O negative blood..I know that now…however when I was pregnant I had an amnio and the dr. did not give me the RH blood thing. my blood type was unknown at the time so he took my blood and said he was going to test it for type but said i was probably going to be okay..NOT..I got a frantic message on my voice mail saying I needed to go to the ER..four hours in waiting because they had to retest..what a bunch of bull. however, Annika Autumn was healthy and so am I..

  48. Lorry said at 3:18 pm on October 7th, 2009:

    I don’t believe I ever listened in biology when it got to the blood types – I do remember not knowing any of the answers. I am A- and my hubby is A- so of course I ASSUMED both my boys would be A-. The older had A- written on his little baby card on his crib, the younger had just the “-” on his so Mommy assumed the “A” was a given since both parents were “A”. NOT SO FAST……It took me until 2 years ago when my younger went into the army and had a child to find out………….He is O-!!!! Gawd I felt like such a bad mother!!! My dad was O- so I guess that’s where it came from. All I know is that it is all so confusing.

  49. Shawn said at 9:57 pm on October 12th, 2009:

    Lorry to explain how your son is O negative. Everyone carry’s two recessive genes your blood type and O. A have A/O, B type B/O, O has double O/O and AB I do not remember off hand how the AB works.

  50. renee said at 4:29 pm on October 28th, 2009:

    you can also find out if you have diego blood system – positive and negative… rare but only found in a b ab and i am looking forward to finding out if there any others like myself—o – and +,,, very interesting. they said my whole life i was o-(rhogam stuff) and now i find out i am “o+” or some weird thing were I am O- with o+ antigins? and basically that make me o+.. course iam new to this too… good luck if you read this i will look forward to a reply..

  51. Lucy said at 11:36 am on November 6th, 2009:

    I have just had my second miscarriage and am o- my husband is positive, my idiot doctor just thought to check and decieded I needed the jab hopefully by body won’t fight my next pregnancy and all will be well but the wonders of uk doctors really does amaze me how they actually became doctors in the first place, I think I’ll move elsewhere!!!

  52. christine hummel said at 11:20 pm on November 16th, 2009:

    can i have an A negative child is my husband is Apositive and i am o negative?

  53. cara said at 6:48 am on November 18th, 2009:

    am confused what are the most fatel results from amom with negative blood type and a father with a positive blood type(and vise verse)

  54. D Thal said at 10:37 am on November 28th, 2009:

    They give you rogahm for a the rh – factor in preganant woman. I’m O- my hub is O +. Our baby is O+. I will say that my delivery was difficult but i don’t think it had much to do with the difference in blood types. back before rogahm it was a huge concern but i think they are on it now.

  55. Kathy said at 1:03 am on December 23rd, 2009:

    I have three 0- children and one B+. I lost four other children to this RH factor. My husband is B+ and I am O neg Du neg which is very rare and causes a lot more problems. I carried to 20 weeks before I misscarried twins. The immune injections were not given when I delivered negative babies; thus, I lost the next pregnancy. Today, doctors give the immune globulin whether the mother has a negative child or not. My B+ child had to go under the special light because of this factor…..

  56. Terry said at 2:20 pm on December 30th, 2009:

    My son was just told he might be the father of a newborn. My son has A- blood and the mother has O- blood…the baby has O+…is that possible. I guess a DNA test will be done shortly, but I am stressed out thinking about this. Any help?

  57. Janice said at 7:50 pm on January 4th, 2010:

    a friend of mine needs a kiney transplant, he is only 47 but has o- blood type. Is there anyone willing to donate a kidney for him? We live in Washington State. Thanks!

  58. Jamie said at 3:00 am on January 6th, 2010:

    O – blood also having a baby with A+ father (lucky guy) assuming baby will be O+!! Sorry about the guy needing a kidney it’s hard to find

  59. Stacey said at 12:54 pm on January 21st, 2010:

    For those interested in how genetics of this work:

    Everyone carries two copies of each gene (one from your mother and one from your father). Depending on which gene it is there is usually a dominant gene and a recessive gene. If you have a copy of each (meaning you are heterozygous) the dominant gene will prevail and that is what your trait will be. If you have two dominant copies that will be your trait. If you have two recessive copies then you will have the less common recessive trait. Therefore, those people with the dominant trait can be carriers of the recessive trait. This is how it works with the rh factor.

    I am A- and my husband O+, both kids are O-. This means my husband is heterozygous for RH factor, he carries both the + and – gene and that is why our kids are -. I however have to be homozygous or I carry both – genes because – is recessive and + is dominant. Therefore, two + can make a – (because you can be + and carry a – gene) but two – cannot make a +.

    Hope this helps, sorry I was late to the party.

    Terry, with the info you have, I don’t think your son could have fathered the o+ child.

    christine hummel, yes you could have an A- child if your husband carries the recessive – gene.

  60. Essie Davis said at 12:38 pm on February 13th, 2010:

    What blood group would a child possibly have if both parents have 0 negative blood types?

  61. Gaybrielle Towner said at 6:17 pm on February 23rd, 2010:

    I found out I was o-negative when I got pregnant, which I mis-carried, my doctor on the second pregnancy said I had no antiboties, which this did not cause the miscarrage, so I find out now the only two people in my family with o-negative blood are my grandmother and uncle. My father is o-negative. With my son Garrett I took the shots through my 28 week and so on, what I want to know is how can my parents be positive and I am negative? What risk do I have having a negative blood type? forgive me this is all new too me as well! I need someone to explain all of it to me, I dont remember learning about any of this..please help!

  62. Gaybrielle Towner said at 6:23 pm on February 23rd, 2010:

    Sorry, i was wrong my father is o-positive! my uncle and grandmother are the only o-negative in my family, my dad constanly picks on me that he is not my dad, my uncle is because we are both 0-negative…now it is starting to get to me, and I am trying to do my own research, which is just making it all confusing if anyone has the time please explain all this thanks!

  63. Lynne said at 10:14 pm on February 23rd, 2010:

    My older sister was born in 1948 and after she was born, my mom’s dr told her not to have anymore children because my mom was O- and my dad was A+.

    My mom tried not to get pregnant again, but she accidentally did in the late 1950′s, and I was born.

    Her dr told her not to get her hopes up because so many Rh disease babies were miscarried or stillborn, or had mental retardation.

    However, I was born 100% healthy, and I’m A+.

    Knowing all of this gives me the feeling that there is a reason why I lived, and that my life has a special purpose (if only I can figure out what it is!)

  64. andrea said at 9:40 am on March 3rd, 2010:

    i am b- , hubby a+. my first born(daughter )was a-, no issue. second born(son) was a+…issue. i had the shots with daughter at 28 week, not at delivery since she was -. with son, had shot at 28 weeks, had extremely severe allergic reaction all over my body starting at 34 weeks, got so bad i had to be induced at 38 weeks after taking oral steroids. i believe as does my doc this is because i was negative and baby positive. i had the rh shot right after he was born too. an hour after delivery my whole rash and hives …gone! any future positive baby i’m not sure what will happen, but i had the shot twice so the docs say all would well. but, who knows, the rash i had only aflicts 1% of pregnant women with negative blood types (oddly enough).

  65. Rachel said at 2:05 pm on March 31st, 2010:

    Ahh, I have O negative blood too! I kinda was creeped out, my dad is A negative and my mom is O positive. And somehow I ended up with O-. Hmmm. The only thing that worries me is if I marry someone with an incompatible blood type and I have to get a shot any time I want to have a kid. :/

  66. Kelly said at 11:45 pm on April 10th, 2010:

    I am o- and my husband is o+ but I only had to have 1 rhogam shot right after my son’s delivery so I’m not sure why some women had to have several shots throughout their pregnancy. My son was a healthy 11 pound baby and 23 years later is still very healthy!

  67. Debbie said at 7:47 pm on April 24th, 2010:

    I’m O negative and wondered if my miscarriage for second child in first trimester could be caused by not having shot early enough? I keep hearing that the shot is given in the 28th week. Is that soon enough?

  68. Julie said at 6:57 am on April 30th, 2010:

    I’m O- and hubby is O+ and we have five children. I had the Rhogam shot with a couple of my kiddos but it really wasn’t a big deal. Just makes me thankful for modern medicine, because had I lived a century ago, I’d probably not have experienced motherhood. ~ cheers

  69. nj said at 4:47 am on June 9th, 2010:

    i have blood group B+ve and my husband’s is O-ve.
    is there any problem in conceiving as i already have one abortion..

  70. Victoria said at 1:21 pm on July 19th, 2010:

    I am O+ and my husband is O- and I am pregnant. Is there going to be any risk at all for me or the baby?

  71. mihow said at 3:30 pm on July 19th, 2010:

    Victoria: No. It’s been a while since I read up on this, but no. I think it’s if YOU have the O- that’s when there’s a problem. Might google it, tho. If I’m wrong, I’ll post again.

  72. Samantha said at 10:40 pm on August 18th, 2010:

    Guess what guys! Me and my husband are both O- and my little girl came out A+ so two O- can make a + and yes I have to get the shot when I was pregnant the ro gam or what ever it’s called. My husbands mom Is A+

  73. Cherie said at 3:53 am on October 26th, 2010:

    I’m confused. Both my parents are O positive, my siblings O positive and I am O negative. I have had 3 pregnacys, which were all very difficult, labor at 5 months, bed rest and medication to stop delivery, induced at 8 months, but I was never made aware of any shots I needed. My childrens father is O positive. Could this be why I had such hard pregnacys and deliveries as well. And could I really be O negative when my entire family is O positive and be related to them? I do not understand all of this and I do not understand why so many woman had to get shots when they were O negative and pregnant, I was never made aware it was an issue.

  74. oneg said at 4:00 pm on November 4th, 2010:

    Samantha- If you and your husband are both O negative then it’s impossible for your child to be A+. I know this sounds extreme but I wonder if there was a mix-up at the hospital. These things happen sometimes. Good luck!

  75. Jamie said at 3:24 pm on March 15th, 2011:

    i am 0- also and i have had 4 kids my husband is a+ and i am fine they give me a shot called rhogam around 20 weeks into being prego then they give you another after you have the baby if the baby is + blood type the rhogam stops the + blood from entering the – blood if you dont get the shot the blood can mix and that is what the call RH sensitized and the – blood will fight the + blood type and that can end up killing the baby or the baby can have other mental prob. I just want you to know that i am fine and have 2 kids that are a+ and 2 kids that are 0- just get the shot and every thing is fine you can have as many kids as you would like

  76. christy said at 6:02 pm on March 22nd, 2011:

    pls what happens when you are o-,and you have had 2 miscarriages, and you are yet to receive the shots?

  77. Biyo said at 8:45 pm on April 1st, 2011:

    Sorry to hear that, Christy. I would suggest you get the shot before your next pregnancy and during as directed by your ob/gyn. A miscarriage implies your body has developed antibodies against rh + (D), and would likely react to a pregnancy with similar factor in the future.

  78. Biyo said at 9:01 pm on April 1st, 2011:

    To Judy from April 8, 2009: just wondering if you don’t have that backwards, i.e., My reasoning is that, if your dad ‘s type o-, then being a “universal donor” blood type, this should have not triggered a reaction from his mother regardless of her blood type, unless of course, there were other circumstances? Perhaps someone can clarify. Thanks. Great website!

  79. Casey said at 6:16 pm on June 14th, 2011:

    I’m 25 weeks pregnant and just the other day they told me at the doctor I need the rhogam shot. I’m type o negative, but they didn’t even bother testing my boyfriend (the father) just because I’m negative and they probably don’t trust my word on paternity because we’re not married. I’m dreading this!

  80. Sam said at 8:24 pm on July 7th, 2011:

    Here is an interesting fact I learned. I recently donated blood the the American Red Cross. They asked me what my blood type was and I said O + because both of my parents and sisters are. A few weeks later I get a card in the mail telling me I am O-. I asked my parents if they were sure of being O+ and they said yes. So I call the American Red Cross, and asked them to double check. They said they always do and that I am indeed an O -. Someone please tell me how I am an O- when both parents are an O +? They both had RH factors of +

  81. Suzy said at 8:01 am on July 23rd, 2011:

    Sam, my mum asked the red cross how I could be O negative blood group as my mum is AB+ an dad is not O negative.

    Red Cross Blood Bank told mum it is grandparents blood group that I am O negative in this case.

    I am definitely my dad’s as I look exactly like him and all family.

    Hope this helps answer your question.

  82. Michael said at 1:35 am on August 11th, 2011:

    Just bringing this back to the year 2011. I really enjoyed this thread. Hilarious & learned something.. o-

  83. Jill said at 7:33 am on September 22nd, 2011:

    Our mom was Rh- it comes from both sides of the family. Two +’s can have a – child. the genes are recessed from both sides of the family.
    Iam the only child from our moms 2 marriages and 7 children that test positive for rh- although my sibs or their children can have a rh- child because all of them have the reccesed gene.

    My first born is + and I had to have the shot in the butt after I gave birth.
    I had one miscarriage and a dnc and a second full term pregnancy and had to have the shot after each.

  84. Bayley Riddle said at 11:18 am on November 22nd, 2011:

    hey this is something i never knew about my mom blood type.i am ten years old but im preety facinated.My mom was talking about her getting shots during her pregnencies while i was reading and she said that if she didnt take the shots she would get sick.

  85. sky said at 8:30 pm on December 6th, 2011:

    I am only nine. So in my fifth grade class we had to study a subject of science I studied blood type o negetive. I studied it and by a weird affect my mom told me I was it. I told my health teacher i dont need to learn about hiv. I am curious in it cause oddly no one in my family had it. This is interesting. I shall use it for my report.

  86. Mary said at 8:06 pm on December 28th, 2011:

    So here’s one for you mom’s and medical people out there; my middle daughter, child #3 was born O+ but when she was pregnant with her birst baby she fliped and became O- and now that she is preganat again she is O+ the Dr’s say she is double O negative or was it double –O has anyone out there ever had that one come up? email me at marymduff2005@yahoo.com

  87. Sarah said at 5:56 pm on January 25th, 2012:

    So I am o- and my boyfriend is o+ and I have been told that I couldn’t have children with him. He is the love of my life and I don’t know what to think about what I have been told. Hope it’s not that we can’t have children together, just is a little harder then others. Advice? Should I get the Rh shot before we try to concieve?

  88. Kristie said at 12:45 pm on July 18th, 2012:

    I am a mother and I am o-, both of my children are 0 positive, and my ex husband is 0 positive. The doctor can give you a shot for RH factor, which will help your body to not reject a baby should he/she have an o positive blood type. As far as I know the shot should help greatly, so it is good you are aware of your partners blood type. My kids are fine and healthy.
    Just being educated to your blood type and your partners blood type will help you be aware of what steps need to be taken. Since 0- is somewhat rare, it is not unusual to have a partner with a positive blood type. Good Luck.

  89. Helen said at 4:36 am on August 11th, 2012:

    Am facinated by this o neg subject since having boyh my children, I am o- and both my children are o-, dont know what blood group my husband is, i am assuming that he is also 0-, will i be correct in this. My Dad is o- too. It freaks me out with the percentages of o- in the world that we have met in the first place! Another question, inbetween both my healthy children I had two miscarriages, after the first one nothing happened, after the second one I was given the anti D injection. Why would I need this if my hubby is o- too (again only assuming). It was a really hard time in my life and I think more research should be done on this subject, can anyone answer my questions? x

  90. anna said at 2:40 am on September 16th, 2012:

    Hate to interject, but but two people with O+/RH Pos. blood types cannot have children born without the RH factor, it’s physically impossible-and had it been possible you and your brother would not be alive today, I can assure you. The RH pos. factor would work against itself on the fetus and destroy it. One of your parents had to be An RH negative factor [whether O-, AB-, B- or A- for you to have a neg. factor.

  91. anna said at 2:41 am on September 16th, 2012:

    …and blood types can’t mutate from pos. to neg or any variation of those…

  92. Mary said at 3:19 pm on July 4th, 2013:

    Someone posted here she felt special because she has AB type blood and everybody wanted it. Correction: AB is special because they can receive blood of any type. They can only give to others with AB. The only blood type that can be given to any other blood type is O negative. We O negatives are lucky we can give to everybody, but we are the only type that can receive only from other O negatives.

  93. colleen said at 6:28 pm on November 11th, 2014:

    hi please can someone answer me im desperate my mum was Opositive dad ONEGATIVE MY SIBLINGs are all O I am APOSITIVE AM I THERES????

  94. mihow said at 9:29 am on November 12th, 2014:

    Colleen: I’d say that warrants a test.

  95. Marlo Kuhnmann said at 6:16 pm on March 2nd, 2015:

    My maternal grandmother is Blood Type A
    Negative, my mother is Type O Negative, and I am Type B Negative. Both my grand-
    mother and my mother had difficulties in
    pregnancies because of their Rh Negative
    blood types. Because of their experiences,
    I would greatly prefer to have an Rh Negative partner regardless of his race,
    religious, or ethnic background. The existence of Rhogam shots does not change my opinion.

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