Anti-D Question

[Caz1974]

This is hypothetical, so I don't necessarily need advice, although I suppose it may be useful to potential mothers. I just need a factual answer to the following question...

Mother is -ve, father is +ve but 1st child was -ve. Therefore with 1st child being negative, there could have been no risk of positive antibodies being produced in first pregnancy due to mixing of blood to add additional risk to the subsequent pregnancy, regardless or not of if that second child turns out to be +ve or -ve.

Only if the second child is +ve is there then an increased risk in a possible third pregnancy.

Is that hypothesis correct? I've searched for an answer and found none. Perhaps the mums net community can help answer?

Don't think that scenario could happen as the rhesus antigen(protein)carried on the blood cell is a dominant one - in other words if one parent carries it and is therefore positive the child will also be positive. The child can only be negative if both parents are too. Please feel free to correct me if I'm wrong.

I'm negative and my partner is positive. Apparently baby can be either, so I need the jab : (

Thanks Giraffe and Panda (not often you type that!).

You have the jab, not for the current pregnancy, but to prevent problems in any subsequent pregnancy, right? Due to potential mixing of positive and negative blood between mother and baby creating antibodies.

So the question is, if a first child turns out to be negative, there's been mixing of +ve and -ve, and therefore no increase in risk on the second pregnancy?

I know it's quite a specific question.

No, I don't think your hypothesis is correct, Caz - sorry! I'm currently pregnant with my first child (and first pregnancy) and found out a month ago that my baby has Rhesus disease. I'm Rh- and my husband is Rh+, so I was scheduled to have the routine prophylactic anti-D jab at 28 weeks. Sadly, they discovered before that that I had developed anti-D antibodies in my blood - despite there being no antibodies in my booking bloods. So, although this may be very rare, it is possible for there to be sufficient sensitisation events in the same pregnancy to create these antibodies. (I should add that I have had no bleeding or other traumas/injuries - but something like 1 in 100 women experience a "silent bleed" during pregnancy that can be enough to sensitise them if they are Rh- and carrying a Rh+ baby.)

It's also not true that a baby will always be Rh+ if one of the parents is. Yes, the Rh antigen is dominant, but all that means is that one of the parents could carry a +ve and a -ve antigen - i.e. they could be heterozygous - in which case they would themselves be Rh+ but would have a 50% chance of passing on either gene to their children. On the other hand, the Rh+ parent could be homozygous (they have two copies of the Rh+ antigen), in which case they would always pass on the +ve antigen. In your hypothetical situation, the father is obviously heterozygous, since he has already fathered a Rh- child.

Sorry, I'm not sure if I've explained that very well!

Panda Im negative, dh is positive
dc2 turned out to be negative as well, its rare but it happens.
the jab is not only for future pregnancies, but also in case you get injured during pregnancy (chance of bloods mixing) or need blood transfusions in the future.

Panda each parent carries 2 genes. THe child will get one form each of the parents. You are right that the positive is dominant but a positive parent could also carry a negative gene.

If you are rh neg then the only combination for you is ne:neg so your child will inherit neg.

If you are rh pos then you could be pos:pos or pos:neg. Your child could inherit your pos or your neg.

So clearly in the case described by Caz the father is pos:neg and the child has inherited his neg gene in addition to the neg from the mother.

So yes, I believe that if the child is neg, there is no need for the jab after the birth and so no risk for a second pregnancy. However, the mother would still be neg so in a future pregnancy would have the jabs during the pregnancy in case the second child turned out to be positive. Of course if the second child is positive then you would get your jab after the birth thus protecting a 3rd pregnancy in teh future.

And grumperina has brought up the other possibility, that you could have a bleed in any pregnancy before you get your jab and affect the baby you are carrying.

My mum is negative and dad is positive and I am negative. I understood it that everyone carried sort of two blood types so you could have mum neg, neg and dad pos, neg and that would make a negative baby.

I think there could still be a risk in a second pregnancy as blood could cross over before the baby is born and cause a problem, it doesn't have to just be due to childbirth. I'm not an expert though!

You only produce antibodies against a protein you don't have.

If you don't carry the rhesus D antigen you are rhesus -ve and if the baby is -ve too that means you won't produce antibodies against them as they don't have the antigen either. So if the first baby is -ve you won't make any antibodies against them. If the second baby is rhesus antigen+ve that means they're carrying the protein and you mount a reaction by producing antibodies which in theory would only be a problem in a 3rd pregnancy against another rhesus +ve baby as the antibodies would attack them. That scenario would only happen though if the father of the first and second babies was different and the second father was rhesus +ve.

The problem is you see that if the mother is negative the only way they know what the baby is likely to be is by testing the father which i don't think is done routinely as it 1) could open a can of worms regarding paternity and 2) due to expense. The easier and cheaper thing to do is to just give the mum anti-d to prevent her mounting a response and the assumption is made that the child is positive.

Hope that makes some sort if sense!

I asked about this, as I'm Rh- and had Anti-D at 28 weeks. It was a bit ouch to say the least, so I asked if the next one (post birth) could be done while epidural was still in (I know, I'm such an utter wimp). MW reckoned although it wouldn't do me any harm, they would probably have to wait till baby blood type result came back, and that knowing DP was +ve didn't mean DC would be.

ime they only give the anti-d after birth if you need it. the baby is tested and if baby is positive you will get the jab. if not there is no need.

Ladies i stand corrected! Completely forgot about the heterozygous factor! I knew someone would come along who had a better idea than me- slumps back onto sofa and nurses little grey cells!

Grumperina- hope your pregnancy's otherwise going ok :)

Sorry to bang on about this, Panda, but I'm afraid that's not right. Yes, it's only a risk for a Rh- mother who is carrying a Rh+ baby. But a man who is Rh+ can father a Rh+ baby or a Rh- baby if he is heterozygous (i.e. if he has a Rh+ gene and a Rh- gene). He will still be Rh+, but he would have a 50% chance of passing on either gene. And you wouldn't know whether the baby is Rh- or Rh+ until it is born, unless you did some sort of invasive testing in utero. They can take fetal blood to check the baby's blood group, but it carries a small risk of miscarriage. (I think they can now also determine the likely blood group from a special sort of maternal blood test.)

And it's also not true that it would only be a problem in subsequent pregancies - I'm proof that this isn't the case! Personally, I wouldn't take the risk and would have antenatal anti-D if offered it. I would love to be able to do this (it's too late for me) - and any risks of the jab are tiny compared with the risks to current and future pregancies once you already have antibodies in your blood :(

Ooh, X-post there, Panda - sorry, I'm just a slow typist.

The pregnancy's going ok so far, but I have to give blood samples and have a scan every two weeks. Fortunately, they picked up the antibodies so late in the pregnancy that they reckon there's not much chance it will have affected the baby this time. But it's much more severe with every subsequent pregnancy, so that's a bit of a worry. And I'll have to be induced early this time - bit scared about that, to be honest!

Ooh sorry to hear that Grumpina- not sure i wouldn't be a little nervous too about it. Does being induced mean you at least have a date to plan around so you know when your leave can start etc? -sorry I'm a silver lining kinda girl!

No, sadly no date yet - the plan is to keep monitoring (I'm nearly 33 weeks now), with the idea of keeping going as long as possible, but whipping the baby out if my antibody levels get too high or if it shows signs of distress in the scans. So it could be any time between now and 40 weeks! (But I won't be allowed to go overdue.) Most likely 38 or 39 weeks, I think - it would be nice if we were home for Christmas, though! :o

Sorry for hijacking the thread

Hi ladies

Grumperina, you're right re the maternal blood test: I'm in a study for Rhesus neg women who have extra blood tests during pregnancy to predict babies blood group. Just had my 28 wk check and baby is predicted to be negative so haven't been given any anti-D. Since my husband is also Rh neg, I know baby couldn't be anything else, but it's nice not to have to have the injections!

I hope everything is ok with your baby? How are they managing your pregnancy differently now they know about the rhesus disease? Hope you don't mind me asking, just curious as to how this will affect the rest of your pg, type of birth etc.

I'm also Rhesus negative so finding this thread really interesting. My husband is also Rh- so I had just assumed that it had basically turned out to something I didn't really need to worry about.

But now I'm wondering and this is probably a really stupid question, is it possible for the Rh+ to be recessive in the same way Rh- can be? i.e. could two negative parents make a positive baby? If I still have to have anti-D that's just the way it is.

grumperina good luck with everything sounds like you're being well looked after.

I'm -ve and husband is +ve. First and second children are both -ve (they could have been either) and so I didn't need the Anti D after birth, although had had it during pregnancy. Now due with 3rd baby, and will probably have the Anti D again, even though this baby is certainly our last!

Also, during my first pregnancy I slipped in the bath and there were found to be fetal cells in my blood and I had extra Anti D at that time. I remember being terrified by it all and totally confused as there didn't seem to be much information. Was happy to find out that both children were -ve also and reduced risk etc.

I'm RH- and my husband is RH- also, so we can't have a Rh+ baby, my GP confirmed this but advised me to have the anti-d anyway and remain within the system as they monitor other antibodies in the blood (maybe he didn't take my word for it that all my pregnancies were to DH...). The only way a Rh- baby is guaranteed is if both parents are Rh-.
I've had anti-d a few times and can honestly say it doesn't always hurt, on 1st occasion it really did (like a shard of glass being pushed into arm) but never been as bad since, if that eases your mind a bit.

Hello ladies,

I don't mind at all your asking about how my pregnancy is being managed, Ba8y1 - in fact, I'd be glad to share, as I've found it so hard to find out this information myself!

The main differences are:

1. I have to go to the hospital every two weeks, where I'm under the care of a Fetal Medicine consultant, to give a sample of blood for antibody testing and to have an ultrasound scan.

1. They're monitoring the levels of antibodies in my blood to assess the risk of anaemia in the baby. The ultrasound scans look at the velocity of the blood flow through the middle cerebral artery, which is also a good indicator of whether the baby is anaemic (i.e. has been affected by my antibodies crossing the placenta, as they would destroy the baby's red blood cells and cause anaemia).

1. If the baby had shown signs of anaemia before 32 weeks, they would have considered treatment in utero (including a blood transfusion for the fetus!). After this time, they would consider induction and early delivery. As long as the monitoring suggests a low risk of anaemia/haemolytic disease of the newborn, they've agreed to leave it as long as possible before induction (although I'm not going to be allowed to go over my due date), in order to give the baby the best chance to mature.

1. I'm going to have to give birth in the consultant-led delivery unit, almost certainly induced (with everything that that implies: continuous fetal monitoring, no water birth, limited movement, etc.). I'm not very happy about this as I had been looking forward to an active birth in the midwife-led unit, but that can't be helped :)

1. There will be a paediatrician standing by at the birth to assess how badly affected the baby has been by my antibodies. I've been told that we'll be in for a couple of days while the baby is monitored for jaundice or anaemia. Future treatment will depend on how early the delivery is and how severely affected the baby has been.

1. I was expecting to be told that I couldn't have any more children (especially as my husband's blood has been tested and he is homozygous Rh+ - i.e. all children we have will definitely be Rh+). However, the consultant seemed quite relaxed about this, especially as the Rhesus disease has developed relatively late in this pregnancy. Apparently it will develop a little earlier in each subsequent pregnancy, so I don't think I could have another 10 children!

Sorry again for the blatant thread hijack - I'm finding this all really interesting (despite the worry!), so I hope that others might also find it interesting/useful! :)

There's no/very little danger to that baby, but you should still take anti-d in case that baby is positive, because there will be a risk to future pregnancies (if they are positive) if that baby's blood mixes with yours at birth, as only then will you be producing antibodies against the rhesus antigen.

And the rhesus antigen is not dominant - if you are negative and your partner is positive than there is an equal chance of you having positive or negative baby. x

Hi,

As someone has already said, there can still be unforseen circumstances that mean you can have a problem with a first pregnancy or in a subsequent one despite the first being -ve.

I am Rh- and DH is Rh+. With my first pregnancy, I had no bleeds or complications but DS1 was Rh+ and had Rhesus disease and we didn't find out until he was 2 days old. I still don't know why I produced the antibodies. I reckon i must have had a silent bleed or a previous early miscarriage that I didn't know about.

DS1 required 5 days of phototherapy treatment and we were in hospital for 10 days overall.

I had the anti-D injections during pregnancy no.2, but DS2 had Rhesus disease too and ended up with the same treatment. They did find out earlier this time and we were only in hospital for 7 days.

I'm now pregnant with DC3 and as we don't know if DH is ++ or +- there is a 60% chance (I think I've worked that out right?!) that DC3 will be Rh+ as well and will require the same treatment.

Thankfully all the DCs have been absolutely fine after treatment and are now very healthy. Grumperina - hope this puts your mind at rest that you will be able to have more children (if you want!)