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Anti m antibodies

(15 Posts)
Curlywurli Mon 10-Mar-08 19:50:11

Hi, I was wondering if anyone has heard of these and knows if there are any implications/ what they are. I'm 29 weeks and they found them when I had my first blood test. I had my bloods redone last week and apparently they are still there, but my midwife said they had to be titered or something. I'm still waiting for the results over a week later and am beginning to stress. I can't find any info about them and no one is telling me anything. Thanks

justjules Mon 10-Mar-08 21:11:55

sorry i cant help but bumping for someone who might be able to

madmumNika Mon 10-Mar-08 21:54:21

Hi Curlywurly, I have Anti E antibodies which were discovered in my first pregnancy after the first blood test. Have they tested your partner yet for his blood antigens? Essentially your antibodies will react to blood antigen 'm' so if your partner has this blood antigen there is a chance your baby has it too, and if your maternal blood was to mix with the fetal blood (the placenta stops this happening directly) your blood antibodies could attack your baby's blood which can cause serious problems (called Haemolytic Disease of the Newborn- HDN). Normally your blood won't mix with your baby's unless you have a bleed e.g. from placenta praevia or trauma e.g. a bad bump to your bump. To check that your blood isn't reacting just in case it has mixed the docs re-check your antibody levels usually every 4 weeks from 28 weeks (in the third trimester maternal-fetal blood mixing is more likely). The titre essentially assesses the amount of antibodies in your blood- so hopefully they will stay the same (ie. your blood is not reacting to your baby's). If the levels do start to rise they will increase monitoring by taking more frequent blood tests and possibly more scans. They usually have a threshold that once the antibodies go over calls for action (i.e. your blood is reacting to the baby's). In severe cases they have to do a blood transfusion in utero to your baby. BUT this is VERY rare. I have had two pregnancies, in my first my antibody levels did start to rise (my partner has the blood antigen I have antibodies to) so it seemed my blood might have been reacting with the baby's somehow (in spite of no trauma, bleeding etc) but they didn't reach the threshold for further action- saying that DS was born at 30 weeks due to pre-eclampsia (completely unrelated) so the antibodies didn't have much chance. He did have severe jaundice though which was in part due to the action of my antibodies on his blood.

With my second pregnancy my antibody levels didn't rise at all and I had a healthy girl at 36 weeks.

There's some more info at:


Please try not to be scared by all of this, it is VERY RARE that anti-M antibodies cause HDN but the docs are doing the correct monitoring just in case.

Good luck with the rest of your pregnancy- hope it all goes smoothly!


waggledancer Mon 10-Mar-08 21:54:43

Just googled and found this, Hope that's helpful.

Curlywurli Tue 11-Mar-08 19:17:16

Thank you for your help. I've been really worrying about this, but you've managed to give me some interesting info- which is more than my doctor's have!I'm still waiting for my results so I think I'm going to phone the hospital tomorrow. They ordered the tests so they should know the results. Thanks again

addictedtoharibo Tue 11-Mar-08 19:30:49


I had anti M (well still have anti m lol). Nothing to worry about - my consultant and the blood work team dont seem to know what it is but know it doesnt cause hemolytic disease so that is the great news. Well technically it really really rarely causes it.

Very little is known about it - few studies but they are not bothered.

My titre (level) was very low - almost non existant or very low. As long as it doesnt reach over a certain point they are not bothered by it. I think if it goes high it may cause jaundice?

The problem comes for you if you need a blood transfusion they will want to match the blood with anti m blood - probably need to get it from a bigger blood bank. But you are unlikely to need it and im sure there is some blood they can give everyone (not sure of details).

The first pregnancy they monitored me every 4 weeks (very annoying) to see what would happen. They also said i couldnt have the home birth i wanted because of it but didnt seem to be able to give me a reason why.

This time they barely seem bothered - are measuring it again and if its low they will check infrequently. I am also allowed my home birth with no questions at all - so that says something!

Dont worry about it - it really isnt anything to concern yourself about. Dont google it - there is very little anyway and the very very occasional scare story (which just isnt the case). As a first time mum i was really concerned but had forgotten i had it until your message


w1don Mon 08-Jun-09 20:51:15

I also today found out i have Anti m in my blood, When asking the nurse who took my second lot of blood today what it was she looked as confused as i did lol. By the sounds of what i've heard and read people don't seem to know much about it or worry about it. This is my 1st baby and im 12 weeks gone and i thought getting pregant was going to be the hard thing but every couple of weeks there seems to be something new to worry about!.

I wasn't going to join this wed site and just wanted to read peoples replys but its nice to know other people are going through the same thing and your not the only one.

Thanks for all your comments its made me feel better.

Don. x

peppapighastakenovermylife Sat 04-Jul-09 21:37:46

I had Anti M - they wanted to monitor me more in my first pregnancy. The second pregnancy they just took blood every 4 weeks and although I needed to be under consultant care I still had her blessing for a home birth.

Both babies and myself were fine. They dont seem to know much about it just that it doesnt seem to cause any problem - especially if it has a low titre. Any questions just ask - I almost went mad in my first pregnancy so understand if you are worried - for me though it was nothing to worry about xx

bethylou Mon 26-Oct-09 21:33:31

You lot are brilliant. I came home from the midwife today feeling really concerned and upset, having heard that I have anti M antibodies, as the midwife really didn't know very much and wanted me to wait 5 weeks to see the consultant. I've looked on the internet and haven't found much but am very reassured by your posts (as always).

I went to the appointment on my own (thinking it was just a case of weeing in a pot and listening to the heartbeat as usual!) and tried to take in what I was being told. You mention the titre (level) - do any of you remember what the threshold is? I think she may have said 32 and my level is currently 16 (well, it was 13 weeks ago when they found out and forgot to tell me... angry) I think that was supposed to be low risk but if any of you can confirm that it would be great (or send me in the direction for any more info).

GrandmaBarb Wed 18-Aug-10 01:06:56

My daughter is 23weeks and has just tested positive to anti m antibodies. The post birth complications she has been told to expect are identical to when she was born. Jaundice, low birth weight, difficulty feeding (she was fed with a tube for almost a week) Should I presume that I have passed this on to her and if either of them need blood transfusion, would they accept my blood (I would also have the anti m antibodies wouldn't I)

peppapighastakenovermylife Wed 18-Aug-10 05:59:22

It really depends on her titre level - so how much of the antibody she has. I only have trace levels and have had big healthy babies who fed well with no problems. I have even had a home birth with no problems. Certainly never got to the point of needing transfusions or anything.

She will most likely have regular blood tests to measure the titre level. If it is under 32 (and this is high, mine has never risen over 2) then it might cause issues. Typically though it is only something to worry about if either of them need blood - and then it is only a case of matching her with anti m blood.


thefatladyscreams Wed 18-Aug-10 08:31:46

Another anti M person here. I'm 34 weeks with my first and have been told that it shouldn't be a problem and that "as far as antibodies go it's not a bad one". Very rarely causes HDN which is the thing they worry about in the main. So far they have retested once to check the levels hadn't risen, referred me to a consultant as standard practice (got seen by their assistant as everything was so routine and got a growth scan as a precaustionary measure) and been told I'll need cord bloods taken at birth. I initially googled when I found out (and read all sorts) but I'm pretty relaxed about it now. I've just got a new midwife and asked her if it affected my choice of where to give birth - she said not at all and that anti M was nothing to worry about.

I think a key thing is the titre level as peppa says. If you're worried, book an appointment with your GP or midwife to talk it through. I did this and my GP went away to look into it and came back very reassuring.

Didn' realise there was were so many Mumsnetters out there with anti M!

NannyTreeSally Thu 26-May-11 18:05:20

I have anti M too and it's very reassuring to read all of your comments... i hope that i can get my homebirth too x

GothMummy Thu 26-May-11 19:30:17

Hi there
I have blood group A rh negative with antibody M. I found this out when donating blood prior to pregnancy. I saw a heamatologist during pregnancy, and he said that it was unlikely to cause problems, and I was allowed a home birth. No problems occured with my son.

I am pregnant again now, 36 weeks, and my letter from my red cell serology report in notes says "antibody M is unlikely to cause heamolytic disease of the new born however at delivery a cord DAT should be performed and if positive the baby's Hb and bilirubin monitored"

It also says the titre is low as is less than 32.

Im not having a homebirth this time for other reasons but my notes also say I have to inform the labour suite when in early labour of my blood type etc so that appropriate blood can be brought in. Good luck Im sure you will be fine, no one has ever suggested it might be a problem in my pregnancies and its the one thing I have not worried about!

Vikster87 Thu 14-Jul-16 20:15:23

Hi everyone,
Hope ok to restart this thread as have just received a vague letter from the hospital to say my blood has been sent to the nhs blood and transplant reference lab for further investigation.
I had two blood tests one as my original bloods showed a trace of anti m antibodies and the other was my combined screening for downs.
I've messaged my midwife but haven't heard back. Just worried as to why my blood has been sent off for further investigation.
Anyone had similar letters? Just really confused as the letter is so vague.

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