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Discussion Starter · #1 ·
I'm probably thinking about this too much. <img alt="" class="inlineimg" src="/img/vbsmilies/smilies/dizzy.gif" style="border:0px solid;" title="Dizzy">: I have an assignment for my bio class where I need to write a short paper about Rh incompatibility. I know that when an Rh- mother gives birth to an Rh+ baby, some of that baby's blood enters the mother's body and the mother produces antibodies against future Rh+ babies. But what I don't understand is that when that mother was a baby herself and born, and if <i>her</i> mother was Rh+, she must have had her blood mix with her mother's at birth and already developed the antibodies. It's not like she had never been exposed to the + blood before. So why would hse not have them already in her when she gets pg with an Rh+ baby? Why is the first baby not affected?<br><br>
Any other words of wisdom or interesting facts I can add to the paper?
 

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what you are saying is possible-- a mother's blood could enter a child's blood stream and then that child could develop antibodies from the exposure to mom's blood -- I do think that an infant's immune system is not well developed and that may be why it doesn't happen much- there have been studies done on this-- Rh- infants delivered of Rh+ mothers (Incidence of sentization 0.1%)<br>
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not in every pregnancy does an infant's blood enter the mother's bloodstream to a degree that would cause sentization- so it is not a given that the first pregnancy an Rh- would result in sentization ----- here is some stats<br>
If Husband is Rh Nega & inf Rh Neg Rate = 0 If husband Rh + Homozygous and ABO compat Rate = 16% If husband Rh + Homozygous & ABO Incompat Rate = 7 % If infant is Rh + ABO Incompat Rate = 1.5 - 2 % If Husband Rh + heterozygous & ABO Compat Rate = 8 %*<br><br>
*is from Conn's Current Diagnosis And Manning's Fetal Medicine
 

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I think that the baby's blood can potentially mix with (into) the mother's blood at birth if she has tears or maybe where the placenta detaches, but the mother's blood would not become mixed with (into) the baby's unless the baby had an open wound somehow.<br><br>
(I don't think the umbilical cord/placenta counts here, the placenta protects the baby and the mom from sensitization throughout the pregnancy).<br><br>
I am by no means an authority but this is my theory.
 

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It seems like the most important missing piece of info here is that at birth, mom and baby's blood have the potential to mix, but do not always mix. Rh- mothers choose to receive RhoGam because of this potential. I believe that in an unhindered birth and immediate postpartum, the mother's and baby's blood will not mix at all in the vast majority of the time.<br><br>
In regards to a Rh+ mom birthing a Rh- baby.....just thinking about the mechanics of the blood mixing, it is usually from the placenta to the mother through the uterus, often during 3rd stage. So, it would seem to me that the baby wouldn't really be getting mom's blood if their blood were to mix at birth, but that some of baby's blood would be entering mom's body.
 

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<div>Originally Posted by <strong>Prensa</strong> <a href="/community/forum/post/7893242"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">(I don't think the umbilical cord/placenta counts here, the placenta protects the baby and the mom from sensitization throughout the pregnancy).</div>
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It does unless there is some sort of trauma: car accident, a major fall, a managed 3rd stage with cord traction, etc.
 

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Discussion Starter · #6 ·
Thanks so much for the thoughtful answers! I'm learning so much! It's interesting that mom's antibodies can pass through the placenta and protect the baby from pathogens, and also through breastmilk. But I am guessing this is passive immunization and eventually the baby willl have to make its own antibodies in order for the effects to last.<br><br>
So, if an Rh- woman gives birth to an Rh+ baby and does not know the blood type of the baby, or chooses not to get the Rhogam, does that make all future babies at risk assuming they have the same father? If she has second thoughts about it 6 months later it's too late, right? There's nothing she can do to protect future babies. Have you ever seen this happen in your practice?<br><br>
Is ABO incompatibility ever a really big problem? According to my sources the effects are usually mild such as jaundice.
 

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<div>Originally Posted by <strong>Lennon</strong> <a href="/community/forum/post/7893262"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">It does unless there is some sort of trauma: car accident, a major fall, a managed 3rd stage with cord traction, etc.</div>
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right, but is it a two way street? meaning: can the baby become sensitized in any of those instances or just the mom? I honestly don't know...
 

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<div>Originally Posted by <strong>USAmma</strong> <a href="/community/forum/post/7893331"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Thanks so much for the thoughtful answers! I'm learning so much! It's interesting that mom's antibodies can pass through the placenta and protect the baby from pathogens, and also through breastmilk. But I am guessing this is passive immunization and eventually the baby willl have to make its own antibodies in order for the effects to last.<br><br>
So, if an Rh- woman gives birth to an Rh+ baby and does not know the blood type of the baby, or chooses not to get the Rhogam, does that make all future babies at risk assuming they have the same father? If she has second thoughts about it 6 months later it's too late, right? There's nothing she can do to protect future babies. Have you ever seen this happen in your practice?<br><br>
Is ABO incompatibility ever a really big problem? According to my sources the effects are usually mild such as jaundice.</div>
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rarely is ABO incompatibility a problem --- and if an Rh+ baby of an Rh- mom were to have ABO incompatibility it protects against Rh sentization- yes mom/baby will react to the different blood type but not necessarily the Rh factor. -- Yes 6 months later would be too late to give a shot, what you are hoping to do with an immune globlulin shot is to short circuit mom's body if there was blood mixed and it made it's way into her blood stream- then having immune globulin added to her system is a way to engulf the infant's blood and get rid of it before mom's body is imprinted with the task of tagging and destroying the infant cells, once mom's body has produced antibodies then the body is more sensitive to the presence of blood mixing and so slight mixes that do happen can and most likely will trigger a reaction to a baby with a similar Rh+ status. there is evidence that some times this occurs during pregnancy that is why rhogam is also offered prenatally- it is still only protecting 2-5% depending on the source but that is still a consideration - blunt trauma- crappy nutrition/ average nutrition(low vitamin K which protects/prevents extensive bleeding via good clotting and vessel health as well as vitamin C and flavinoids), connective tissue disorders how deeply the placenta embeds, HELLP or blood mixing in labor/birth hard contractions can do this, rapid birth and abruption that can cause a bleed back- all natural causes that are not "provider" cause.
 

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<div>Originally Posted by <strong>USAmma</strong> <a href="/community/forum/post/7893331"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">But what I don't understand is that when that mother was a baby herself and born, and if her mother was Rh+, she must have had her blood mix with her mother's at birth and already developed the antibodies.</div>
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Normally, blood does not cross the placental barriers, the circulatory systems of mother and baby are seperate, neither's blood is exposed to the others, even though materials carried in the blood do cross. The fetus is never actually in contact with the mother's tissues, it's safely inside two layers of membranes, the chorion and amnion, surrounded by it's own amniotic fluid, the only point of interchange being the placenta, which has 4 layers of barrier cells protecting the fetus from the mother's blood cells. The <i>fetus</i> itself is an adorable bundle of foreign cells growing in a woman's body, and can trigger an immune response in the mother without all the protective barriers. The cells in the placenta are fetal cells, so if there's a partial seperation of the placenta before the placental vessels shut down (such as maternal injury or premature tugging of the placenta during a managed thrid stage), it can cause fetal cells to enter the maternal blood stream at the point of seperation (endometrium), but the barriers of the placenta will prevent maternal blood cells from entering the fetus' blood stream. However, antibodies can be exchanged, which is a positive function of the immune system, except when the mother's body attempts to destroy the foreign cells of the baby, as in Rh sensitization.<br>
Also, the baby's immune system is undeveloped, so if any maternal cells enter the fetal blood stream, it is usually not enough to trigger a response, and the fetus' immune system is not able to produce antibodies. Those cells eventually die a natural death.<br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">So, if an Rh- woman gives birth to an Rh+ baby and does not know the blood type of the baby, or chooses not to get the Rhogam, does that make all future babies at risk assuming they have the same father? If she has second thoughts about it 6 months later it's too late, right? There's nothing she can do to protect future babies. Have you ever seen this happen in your practice?</td>
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Future babies are at risk only if mother has been sensitized, pregnant rh- mamas should be screened with an indirect Coomb's regardless of whether they received Rhogam or not. About 2% of Rh- women who recieved the Rhogam will still be sensitized. But yes, if mom has been sensitized, there are no preventative measures that will protect the fetus. The mom will have her titers taken regularly to watch antibody levels, baby will be monitored for well-being and especially swelling and delivered pre-maturely as soon as it is safe and before the disease can progress.<br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Is ABO incompatibility ever a really big problem? According to my sources the effects are usually mild such as jaundice.</td>
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ABO incompatabilty happens the same way Rh sensitization occurs, when fetal A or B blood cells enter the type O maternal blood stream and the maternal immune system produces anti-A or anti-B antibodies. Jaundice is usually mild and easily treatable with phototherapy and time, but it can be quite severe depending the amount of antibodies produced by the mother, how many fetal red blood cells have been destroyed, and how much bilirubin is produced. It can also cause anemias that require treatment and rarely transfusion. Types O and A are most common in the US, and AO incompatabilty is generally very mild, B is rarer and BO incompatiblity can be more severe.<br><br>
Fascinating stuff.
 

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<div>Originally Posted by <strong>Prensa</strong> <a href="/community/forum/post/7893358"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">right, but is it a two way street? meaning: can the baby become sensitized in any of those instances or just the mom? I honestly don't know...</div>
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From everything that I have read and studied on the topic, just the mom.<br><br>
An excellent book on the topic which I highly recommend:<br><br><a href="http://www.amazon.com/gp/redirect.html?ie=UTF8&linkCode=ur2&camp=1789&creative=9325&tag=motheringhud-20&location=http%3A%2F%2Fwww.amazon.com%2FAnti-D-Midwifery-Panacea-Sara-Wickham%2Fdp%2F0750652322" target="_blank">Anti-D in Midwifery</a>
 

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"and if an Rh+ baby of an Rh- mom were to have ABO incompatibility it protects against Rh sentization- yes mom/baby will react to the different blood type but not necessarily the Rh factor. --"Mwherbs<br><br>
I am a rh sensitized mama, actually a rhogam failure ( I had it only postpartum, not prenatally--but had a huge bleed after a severe shoulder dystocia). I know a lot about rh issues, but I also know there are a lot of unknowns.<br><br>
The quote above, I'm wondering if you could clarify for me, do you mean that an rh sensitized woman who has A- might not have issues regardless of her rh titer if her partner is 0+ for example. I think I may have read it wrong, just correct me <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/smile.gif" style="border:0px solid;" title="smile"> The way I understood it is that if both parents are the same letter, both O's say, then the severity of anemia could be less for the baby.<br><br>
I have an interesting case, in my first isoimmunized pregnancy I started the pg with a titer of 1:1. Then, at 28 weeks I had a sudden jump to 1:32. My son was born at 36 weeks (c/s) and had instant jaundice--mild anemia, 7 days on the lights and then no issues. My second iso pregnancy was 3 years later, I had hoped that time would give my immune system time to accept and maybe lower my titer. Well, my titer was 1:8 at the beginning and stayed there the whole time. I had a healthy boy at 38 +1 weeks and he needed absolutely no lights and had no anemia at all, although did test coombs positive & both boys were o+. My dh and and I are both O's & both c/s I had a est. blood loss of 500 cc's.<br><br>
So, that's my rh story! I hope that helps add to the info here.
 

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Discussion Starter · #12 ·
liseux that's interesting that they can monitor blood titre when you are pg. I was reading how sometimes the baby can be saved in utero by blood transfusion through the cord but I didn't know how they were able to detect the need for one.
 

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Yes, its amazing what they can do to monitor iso pregnancies these days! As recently as 2001 if you showed up pregnant with a titer the only way to check on the baby was to do weekly or bimonthly amnios (!!!!!) When I found out I was sensitized in 2003, I was devastated b/c I had lost my second baby and then got pg right away only to be labeled high risk b/c of rh. I was actually low risk until my titer rose to 1:32, 1:32 is right about where babies run a higher risk of being affected. And they rarely get affected before the 3rd trimester, b/c before that the circulatory systems are very distinct and not as much blood is even in the baby yet.<br><br>
So... now they do ultrasounds called mediocerebral artery velocity doppler, MCA's. They measure the velocity of blood flowing thru the brains biggest artery & have a curve they measure baby by. Cordocentesis and cord Itntrauterine transfusions can be done if baby gets sick. More later...
 

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I'm A- and dh is a-, so we didn't have to worry about this one, but at first (till I realized he was also A-) I was concerned about it.<br><br>
I had talked to my friend (she's a pediatrician) to ask her why some of the information I foudn said it doesn't effect the 1st baby and other information implied that rhogam shots were standard for ANY rh- birth, regardless of birth order.<br><br>
What she told me is that even a very early miscarriage that is undetected could (possibly) cause the RH factor risk in the NEXT baby to term, and since the mother didn't know she miscarried what was thought to be a 'first' baby really wasn't her first. Hence, now doctors made it standard for the first birth too, just in case.<br><br>
I hope that makes sense, just wonder if theres a thread of truth to it, or if it is just another "excuse" used to justify standardizing a procedure despite a true need for it.<br><br>
Jessica
 

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Even the first sensitized pregnancy can possibly cause anemia in the baby. And the second pregnancy may not. Some women have even had their titers disappear. The thing is most OB's have very old knowledge about rh. Perinatologists have the latest data, but even some of them are scared of rh. I luckily had a peri from Italy who specialized in rh pregnancies and was very laid back.
 

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<div style="margin:20px;margin-top:5px;">
<div class="smallfont" style="margin-bottom:2px;">Quote:</div>
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<div>Originally Posted by <strong>liseux</strong> <a href="/community/forum/post/7901571"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Even the first sensitized pregnancy can possibly cause anemia in the baby. And the second pregnancy may not. Some women have even had their titers disappear. The thing is most OB's have very old knowledge about rh. Perinatologists have the latest data, but even some of them are scared of rh. I luckily had a peri from Italy who specialized in rh pregnancies and was very laid back.</div>
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Yup... during my first sensitized pregnancy (with anti-kell, like anti-D, only its a different antibody), my titer went from 1:16 to 1:32 and by the end of my pregnancy it was nontraceable. But my second sensitized baby didn't spend any time under the lights and was much less jaundiced than the first sensitized baby (although i did have the second one a few weeks earlier too)
 

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<div>Originally Posted by <strong>sevenkids</strong> <a href="/community/forum/post/7894206"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">ABO incompatabilty happens the same way Rh sensitization occurs, when fetal A or B blood cells enter the type O maternal blood stream and the maternal immune system produces anti-A or anti-B antibodies. Jaundice is usually mild and easily treatable with phototherapy and time, but it can be quite severe depending the amount of antibodies produced by the mother, how many fetal red blood cells have been destroyed, and how much bilirubin is produced. It can also cause anemias that require treatment and rarely transfusion. Types O and A are most common in the US, and AO incompatabilty is generally very mild, B is rarer and BO incompatiblity can be more severe.<br><br>
Fascinating stuff.</div>
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Everything said was accurate up to the ABO sensitization. ABO antibodies are present VERY VERY early in life (there is actually some debate as to if they are the only antibodies to be actually of genetic origin--many sources say that exposure to certain environmental things). The thing with MOST ABO antibodies is that they are just too dang big to cross the four cell layer, whereas the Rh and kell type are smaller. I forget what's what IgG and IgM. . .anyway in some cases some people produce antibodies for A or B that are the small kind (whichever that is) and those can cause HDN. Overall 15% of all pregnancies are ABO incompatable. In 3% (of that 15%) *mild* HDN will occur and in 1% there can be severe HDN.<br><br><br><div style="margin:20px;margin-top:5px;">
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<div>Originally Posted by <strong>liseux</strong> <a href="/community/forum/post/7899101"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">"and if an Rh+ baby of an Rh- mom were to have ABO incompatibility it protects against Rh sentization- yes mom/baby will react to the different blood type but not necessarily the Rh factor. --"Mwherbs<br>
. . .<br><br>
The quote above, I'm wondering if you could clarify for me, do you mean that an rh sensitized woman who has A- might not have issues regardless of her rh titer if her partner is 0+ for example. I think I may have read it wrong, just correct me <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/smile.gif" style="border:0px solid;" title="smile"> The way I understood it is that if both parents are the same letter, both O's say, then the severity of anemia could be less for the baby.<br></div>
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What happens in a Rh- mom who is O type is that if a transplacental hemorrhage happens the body is VERY quick at responding to the A or B of the baby (Because that immunity is already there) and she destroys the fetal cells before her immune system can learn what Rh+ is.<br>
If a woman is already Rh sensitized it would already be too late because those antibodies are capable of crossing the placenta. TPH does not need to occur to affect the baby.<br><br><div style="margin:20px;margin-top:5px;">
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<div>Originally Posted by <strong>liseux</strong> <a href="/community/forum/post/7901571"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">And the second pregnancy may not. Some women have even had their titers disappear.</div>
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Ah ha! I heard that Rh isoimmunization can fade over time (meaning that well spaced pregnancies might be somewhat adaptive), but I *cannot* find scientific data on it. Actually, you are the first person to post this or who has seem to have heard of this since I learned it from my origional source. Do you know of any documentation of this? I would love to have it <img alt="" class="inlineimg" src="/img/vbsmilies/smilies/loveeyes.gif" style="border:0px solid;" title="Loveeyes">:
 

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Here's a brand new piece of reseach I posted in another thread a while back<br><br><a href="http://www.mothering.com/discussions/showpost.php?p=7623557&postcount=8" target="_blank">http://www.mothering.com/discussions...57&postcount=8</a><br><br>
It's about HDN. The citations are there too and might be good for more info if you're a nerd like me.
 

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Mom with a baby with O blood is not going to have ABO incompatability going on-- now an O mom - will react to A, B, and AB<br><br>
an A mom will react to B and AB -- O+ will give you a reaction to the Rh factor<br><br>
O negative blood is universal donor<br><br>
ABO incompatability is not 100% protective but as someone said before the mom reacts to the blood type first and doesn't have much time to react to the Rh factor- most of the time.
 

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Discussion Starter · #20 ·
I'm still confused about the ABO thing because I'm mostly focusing on Rh for my paper. For the experts though<br><br>
My dh is O+ and I am A+. Our first dd was born and had moderate jaundice. I had always wondered why. Our second dd did not have jaundice. Both of them had similar birth experiences and birth weights. I don't know the blood types of the kids.
 
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