Hiccup #1: The Rh Factor

You are forewarned...it's another long post.  And it's sort of health-technical, so if that's going to make your eyes cross...!

Once we found out we were pregnant, I went to have it confirmed at the doctor so I could begin having regular appointments.  As typical, I peed in a cup and gave blood samples and sat through a mini-orientation of “the folder”.  The folder at my doctor’s office is chock-full of all kinds of literature on anything about babies that you could think to ask about throughout the course of a nine-month pregnancy and postpartum.  I remembered going through “the folder” when pregnant with Audrey (I didn’t sit through “the folder” at the confirmation of our first pregnancy...it was the Wednesday afternoon before Thanksgiving and we all wanted to go home so I opted to come back for it at my 12 week appointment, which obviously never occurred).  “The folder” with Audrey was intimidating because I was a first time mother and the information was overwhelming.  “The folder” with this baby was boring.  There were some things I had forgotten all about, like breastfeeding tips, PURPLE crying, skin-to-skin, etc.  But as soon as the OB nurse mentioned all these things, my brain was like, “Oh, yeah...I remember all that.”  Cake.  We’ve got this.  It ain’t my first rodeo.  I went home and sorted through the folder, keeping like one thing to study because I didn’t need anything else, and got rid of the rest.  Things were going to be so much easier the second time around because neither of us were scared and we knew what to expect.  Plus, we were busy trying to keep a toddler alive, so we don’t have much time to worry...

A few days later, a nurse at the doctor’s office called with the results of SOME of the battery of tests my blood was put through.  All clear.  Everything looked good.  I humorously texted Kyle at work:  “Blood tests negative for STDs.  Whew!”  I’m sure he got a good eye-roll out of that one.  Audrey promptly got sick with an ear infection, so I took a few days off work to stay home with her.  

Audrey learned to paint during one of the periods in which her fever broke

While she was sleeping off her fever one day, the doctor called again, personally this time.

She began with reminding me that I have a negative blood type.  Yes, yes I remember that.  I’ve also shared that on the blog here.  That was the reason I went to the ER after my miscarriage--to get the Rhogam shot since I am a negative blood type.  Read more about the Rhogam shot and what it does here.  I also had the Rhogam shot during my pregnancy with Audrey at 28 weeks and 24 hours after I delivered per procedure.

“Well, it appears that the shot didn’t take.  It is a very rare thing to happen, but it’s possible.  Your blood has antibodies protecting you from the antigen found in positive blood types.”

I was dumbfounded.  I guess I knew this could happen, but I never supposed it would happen to me.  Not to me!  We were told it was so rare a thing.  I think I almost dropped the phone.  “So...what does this mean?”

I think the easiest way to do this is to tell you the questions that I’ve asked my doctor(s) along the way and the answers that we’ve been given.  Obviously I’ve done a whole lot more research on this than in my first pregnancy:

Q: Could you explain to me what all this means?

A: Everyone has two factors to their blood, the type (A, B, AB, and O) and the Rh factor (positive or negative).  If you know your blood type, you are something like AB+ or O-.  You need to know both parts, because both are important.  The Rh factor is a protein (called an antigen) located on red blood cells.  Most people have the antigen and their blood makes it naturally and has been doing so all their lives.  To not have the antigen is not a bad thing and typically does not make one bit of difference in your life, unless you are pregnant or unless you need a blood transfusion.  Just like the blood type, the Rh factor is inherited from your parents.  I inherited a B- blood type from my parents.  The negative Rh factor is a recessive trait, like attached earlobes.  This means that both my parents could technically be a positive blood type, but they both had a negative trait that they passed on to me instead of the dominant positive one.  Since they both passed on the recessive trait to me, I am recessive.  I only have recessive traits to give to my children, because that’s all that was given to me. 

Kyle, however, has a positive blood type.  Since the negative is recessive, he could have gotten a negative and positive from his parents, or two positives.  It doesn’t matter if he got one of each because the positive is dominant and will always overrule the negative trait, just like it does in my parents.  But, that being said, since the positive trait is dominant and that is what Kyle is likely to give, that means that PROBABLY all our children will end up with a positive blood type.  Mathematically speaking, if he has one negative trait, then there’s still a 50% chance of the baby being positive.  If he has two positive traits, the baby will always be positive.  Doctors always will assume that the baby will be positive in these situations and will act accordingly. 

Having a child that’s a positive blood type isn’t terrible.  In fact, it’ll probably make life easier in the long run for most positive Rh factor kids.  People with positive Rh factors can receive blood from those with positive and negative Rh factors (but don’t forget to factor in the letter), whereas people with negatives (like me) can also only receive from other negatives due to the antigens found on the red blood cells.  You can kind of think of it like those who are negative have bodies that are naturally intolerant to the antigens found on positive blood types.  Just like how giving milk to a lactose intolerant person will make him sick, during a transfusion positive blood shouldn’t be given to someone who has negative blood.

To give you a good idea of how many people this affects, my doctor estimated about 10% of the world’s population has a negative Rh factor like me.  Half of those are men.  Since issues only arise during a transfusion or pregnancy, that means that there are only 5% of people in the world (the half of the 10% who are women) who have to think about the issue my doctor was bringing up to me on the phone that day.

Q:  Okay, so if my baby is statistically likely to be a positive blood type and I’m a negative, what does that mean will happen?

 A:  Most of the time, nothing.  That’s what the Rhogam shot is for.  5% of the world’s population are female who have negative Rh factors.  Some of those women are past child-bearing years or choose not to have children, so maybe let’s say 4% of women it is realistically affecting right now or will affect in the near future.  That 4% of people could be in trouble during pregnancy years provided that the man who fathered their children is a positive blood type (which, same statistics apply...90% chance that he is).  If he’s not, everyone’s off the hook and there is much rejoicing.  Now, like in my case, I am of the 4% in child-bearing years with a husband who is a positive.  I have a 3 in 4 chance that I am pregnant with a positive baby.  What could happen is if my blood EVER mixes with that of my child (which is only a risk at a few specific times, like if blood passes from the baby to me via the placenta, delivery, abortion, miscarriage, bleeding during pregnancy, blunt trauma to the abdomen during pregnancy, manual rotation of a baby during a breech presentation, and some types of genetic testing), my blood COULD develop antibodies against the antigen carried in positive Rh factors.  Antibodies could pose a threat to the health of the unborn child because my body is working to protect ME.  I will never be at risk.  But a baby could be.

Now, provided that these aforementioned women live in developed countries with good medicine, they can be given the Rhogam shot, which is designed specifically to help prevent those antibodies from forming.  My doctor stated medically the Rhogam shot is 99% effective.  99%.

Guess what?  I was the one percent.  *hitting my head on the desk*

So you’re telling me of the 4% of people in the world this could affect, I also HAPPENED to choose a partner who was the opposite Rh factor, I also HAPPENED to conceive a positive type child, I also HAPPENED to have been the 1% in which the shot wasn’t effective, I also HAPPENED to have an incident in which Audrey’s and my blood could have potentially mixed, and my blood also HAPPENED to decide to do something about it and develop those antibodies?

“Yep.  That’s what I’m telling you,” said my doctor.

Q:  So how long have I had these antibodies?

A:  We’ll never know for sure when my body started to produce them.  But I can pinpoint a window of time in which I developed this.  I didn’t test positive for these when I got pregnant with Audrey, so it wasn’t due to the miscarriage.  I was permanently deferred from donating blood about six months after I had Audrey, but I didn’t connect the two together (yes, another side effect of this, I can no longer donate blood because they can’t separate the antibodies out of my blood...my blood can’t go to another negative person or they would face exactly the same scenario I’m facing now, and it can’t go to a positive person because my red blood cells would attack theirs).  I’m guessing contact occurred during delivery, although obviously it could have been sooner.

Q:  How do I get rid of the antibodies?

A:  I can’t.  My blood has made them and will continue to make them the rest of my life.  The interesting thing that was explained to me by my high-risk doctor is that the levels of antibodies will vary.  Sometimes they will be higher (usually during a pregnancy of a positive Rh baby) and lower at others (when I’m not pregnant and my body doesn’t recognize a threat or when I’m pregnant with a negative Rh baby and my body doesn’t see it as foreign), but they will always be there.  Rhogam is actually useless to me right now because its purpose is to prevent development of the antibodies, but it also doesn’t hurt, so my doctors are going to continue giving me the Rhogam shot on the off chance that maybe something good comes of it and it can keep my levels low, but the Rhogam won’t make the antibodies go away.  I am being monitored more carefully now because statistically levels rise closer to the end of pregnancy, when the baby is larger and their own antigens are fully functioning.

Q:  What kind of monitoring do I need?

A:  Besides my typical doctor visits, I also need monthly bloodwork to watch the level of antibodies my blood is producing, which will increase to bimonthly if the levels increase quickly or drastically.  Similarly, I also need more frequent ultrasounds to ensure that the baby is not developing anemia.  I have had about five ultrasounds so far (typical at this point is one to two) and will have another in six weeks, and from there, about every three weeks (provided the antibody levels don’t increase).  If they are found to increase, an ultrasound a week until birth.  All the information is shared between my family doctor and my high-risk doctor at the hospital, so there’s no delay in information.  Basically, a lot more doctor appointments!

Q:  What happens if the baby is also a negative blood type?  Couldn’t it happen?

A:  Since we don’t know Kyle’s specific genotype (meaning if he carries the recessive trait or not), there COULD be a 50% chance if he does carry it that the baby also turns out to be negative.  This exact thing happened to my sister, who is also a B- blood type.  Her husband is positive, she got the Rhogam shots, etc. but my nephew turned out to be negative, too.  That just tells us her husband has a 50% chance of producing negative type kids, which is good in their situation!  That means all the shots were moot, but it’s better to be safe than sorry, huh?  She is statistically unlikely to ever develop antibodies.  So there’s no way that my sister now has the antibodies I have, because if her blood did mix with my nephew’s in any way, they were the same type, see?

Q:  Can we get the baby’s blood type tested, just to see if all this worry is even necessary?

A:  My high-risk doctor explained that we can, but it’s extremely invasive and they don’t want to do that unless my titer scores increase to more than 1:8 (I explain what that means further down).

Q:  Worst-case scenario...what could happen to the baby?

A:  Unless my levels are off the charts (and so far, they’re not), with this baby, probably not anything too terrible.  Both my family doctor and my high-risk doctor said that there is a safe zone of antibody levels where the antibodies are present but are relatively harmless, and then there’s an unsafe level in which action is critical depending on how high the level, how many children I’ve had already, and what the baby looks like (determined by ultrasound).  An affected baby would have a disease called hemolytic disease, which you can read about here.  They told me probably worst case scenario for this baby since it’s the first I’ve had since developing antibodies is that it’s born anemic.  This might mean the baby gets blood transfusions while in the womb (crazy what they can do with medicine, huh?!) or after birth.  It might mean that if the baby is too anemic to be delivered vaginally that I have no choice but to have a C-section instead.  Of course, my high-risk doctor said that blood transfusions, especially in utero, are risky, but he also successfully performed TEN blood transfusions on the SAME BABY before it was born!  Can you believe that?!  I feel pretty confident in him.

Notice I said that it depends on how many children I’ve had before since developing antibodies?  The antibodies typically develop after the first baby is born or during a first pregnancy.  Since the antibodies take a little time to mature into a real threat, it usually happens after pregnancy is over and that baby is safe from the effects.  This is what happened with me.  So my pregnancy with Audrey was unaffected.  Depending on whether my levels dip or climb, each subsequent pregnancy might end up being more and more risky.  Let’s say, IF this baby is anemic due to high levels of antibodies and the levels never go down and I get pregnant again and begin with that high level, that next baby would be more at risk for, let’s say, anemia AND heart failure.  If that baby lives somehow, another baby might result in anemia then heart failure and as a result, death.  Because my blood killed it.  Unlikely, yes.  But possible?  Yes.  Know what’s also possible?  My levels rise, enough for this baby to have anemia.  Then I am no longer pregnant, and the levels dip to virtually nothing.  I get pregnant again, but they never rise again to the point where they are an actual threat to a subsequent baby.  Next baby is fine.  It just all depends.

Q:  Will you then make decisions about how many kids you plan to have based off all of this information?

A:  Yes.  For future pregnancies, we might consider getting my blood tested to see what titer score (again, in a second) I’m at before trying to get pregnant to see how bad of a risk it might be to a potential baby’s health.  I doubt this is our last pregnancy because everything is fine so far, but I guess it could be, so I’m soaking it up and trying to enjoy it as if it is.  You never know.

Q:  Am I at risk?

A:  No more than a typical positive type mother is during a pregnancy.  My body is producing the antibodies because it sees the positive Rh factor baby as a threat, so my body is working hard to protect me (and doing a good job apparently, because I feel fine!).  I am at no risk as a direct result of the antibodies.  I guess the only risk to my own health is if we need to have a procedure in which to help the baby and I develop side effects as a consequence from that.

Q:  How are the levels of the antibodies measured?

A:  Titer scores.  Every time I do bloodwork, they take a single vial of blood.  They test it for antibodies.  If it’s positive right away, I have what’s called a 1:1 titer score.  That means they didn’t have to dilute it with anything; it tested positive right away.  Then they dilute it with something (can’t remember what...the high-risk doctor told me, but I just don’t remember).  They dump out half of my blood and put in half a vial of dilution, swirl, and test again.  If the smaller amount of blood with the dilution in it tests positive again, I’m now 1:2--one part blood, one part dilution.  They dump out some more, supply another round of dilution, swirl and test again.  If it’s another positive, it’s now 1:4--1 part blood, 3 parts dilution.  Then it’s 1:8, 1:16, 1:32 and so on and so forth.  An easier way to remember the severity is give each one of these ratios a number.  If you’re 1:1, that’s level 1, 1:2 is level 2, 1:4 is level 3, 1:8 is level 4, etc.  The bigger the difference in ratio, the higher your level of antibodies is.  They will keep diluting and testing until the blood no longer tests positive, or the antibodies are so faint that they’re ineffective.  That tells you what level you are, which is called a titer score.

I am currently--and have been for this entire pregnancy--a level 2, a 1:2.  The high-risk doctor told me anything 1:8 (or level 4) or below is relatively safe...the antibodies are there, but they’re not likely doing anything...hovering around, just in case.  If I were to get to a level 5 (1:16), that’s where we would need to begin to worry, because that’s the start of a tremendous amount of antibodies in proportion to such a small amount of blood.  Remember the woman who had ten blood transfusions on her baby in the womb?  She walked in at the beginning of her pregnancy with a 1:1024 titer score (level 11).  No wonder her baby was in such danger!  But the baby lived and was healthy.

Q:  Should I be worried?

A:  Our doctor stipulated that in my case, any vaginal bleeding at all...ANY...I should come in for a rhogam shot, just in case.  I should not hesitate to call.  She made me promise.

But other than that, not really.

There was one specific instance (the other hiccup I mentioned at the end of the last post and which I will discuss in a future post) in which I was worried.  But overall I feel pretty good, I feel good movement, and the baby looks great so far...I have a positive outlook.  I think Kyle worries more than I do.  As my doctors have both said, it’s a pretty rare thing to have to worry about, but in this case, rare doesn’t mean they don’t know how to treat it.  Our issues are pretty treatable if they do get out of hand, and if they get out of hand and are not treatable...we’ll adapt.  We’ll be okay.  We’ll figure things out.  It’s no one’s fault, not my parents for giving me the blood type, not mine for having it, not Kyle’s for giving Audrey a positive type to cause me to develop these issues, not Audrey’s for putting me in a place to develop it, not the doctor’s because my body didn’t respond to the rhogam, not mine because the antibodies are developing.  It’s no one’s fault and no one has messed up.  We are getting wonderful care and I am positive things will work out the way they are supposed to work out!

For even more reading on our condition, check here and here and here.