I’ve mentioned my antibodies before in a previous post. My blood is a rare type but it’s only an issue when I’m pregnant, or, I imagine, if I ever need a blood or organ transplant. Most people know about the Rhesus issue (when a mother’s blood type does not match her baby’s and therefore forms antibodies in an immune response). I am Rhesus negative, but as yet I have not formed Rhesus antibodies (anti-D), although this is inconclusive at the moment…
My blood is carrying a rare antibody called anti-S. It is separate to the Rhesus thing. At some stage in the early days of my first pregnancy, my blood mixed with Georgia’s and I formed antibodies. Basically, my blood sees my baby’s blood as an enemy that needs to be tracked down and destroyed by an army of antibodies. Our babies will always be S+ (I am S-) because Monte is a homogenous S+ whereas I am a homogenous S-. It will be interesting to see if my sisters develop anti-S in their future pregnancies. Afterall, they have similar genes to me.
There are a few antibodies such as anti-s, anti-S, anti-e, anti-k and anti-D. Most of them are rare; anti-D is the most common and there are now injections that Rhesus negative women receive in pregnancy so their blood does not form antibodies against their baby’s blood. The principles of Rhesus incompatibility are used in the case of anti-S sensitisation. In other words, what happens with anti-D could happen with anti-S, although it might not be as severe.
When I was pregnant with Georgia (#1) my antibody level rose, by 28 weeks, to a high level of 128. I had to have a couple of amnios to check that she was not anaemic. The delightful baby was born 3 weeks early after an “easy” drug-free 3-hour labour and at a very healthy 3.66kg to boot. What a gorgeous, ruddy, chunky, pretty baby she was. There were no signs of anaemia but she was slightly jaundiced, but she did not require any light therapy. My antibodies were more stable with Matthew, only rising to 64 (which is actually high – 32 is considered high). I had to be induced early with him too. He was a healthy 4kg and was born perhaps too quickly but apparently he was not affected by my crazy mean blood.
This pregnancy, my antibodies have risen quickly, from 8 in my first blood test, to 32 8 weeks later and then to 64 a month later. No longer do I have to go through blood tests. My antibodies are considered high and they will not go down – only up, what joy. Instead of blood tests I am having fortnightly or weekly ultrasounds to check baby for anaemia. Technology is amazing. The baby’s pulse in the middle cerebral artery (MCA) is being measured. An increase in pulse will suggest baby is anaemic. MCA dopplers are much nicer than amnios. It’s less intrusive, especially if you have a nice sonographer who does not press too hard on my belly! I imagine that if baby starts getting anaemic, it will receive blood transfusions (which will potentially make my antibodies stir to an even higher level, as our bloods are mixed further). I imagine that if the stage is reached when baby is better off outside my body than in it, I will be induced.
Most people might think that I am unlucky or that I must be eternally concerned for the wellbeing of my unborn child. Of course I am concerned about my children’s health and safety. I know that baby is in good hands and as yet baby is not anaemic. I feel really totally blessed to be able to conceive a child so easily. I think that medical science is developed enough to watch my child and me closely enough to avoid problems that have, in the past, been associated with HDN (haemolytic disease of the newborn).
i just ran across your blood searching for other antibody information. i know that finding out you have an antibody (especially when your doctor is not well versed in the subject can be scary) during pregnancy can be scary. but finding a doctor that can explain it to you in terms you can understand is a great thing. these same antibodies that cause you concern during your pregnancy can also help others. i am a blogger but i also work for a company that collects rare antibodies. if for some reason you might would be interested please email me and i can give you more information.
hi, I’ve been hunting the net for any info about anti S. Early in my pregnancy I was found to have a phenotype S- s+. my husband was checked and we were told that his children would not inhertit the S antigen, this has confused us both, if our baby doesn’t have the antigen and I have never had a blood transfussion, then how and why have I formed the antibodies. I am now 32 weeks, my last titer was 1024, which from what info I have managed to find this is very high (it had doubled in 4 weeks). I have little confidence in the consultant I have been refered to as anything we have ask him tends to come back with ‘i don’t know’. I have a 32 week scan on Monday and they will do a MCA. I am concerned due to lack of info and due to the fact that this is my first pregnancy (at 38 years of age). Can anyone let me know where I maybe able to get more info from as I would also like to donate the cord blood and don’t know if this would now be possible.
+1
I am a little confused, I’m only 12 1/2 weeks pregnant with my third pregnancy. My second was a miscarraige only 3 months prior to my previous pregnancy. Could that be what is possibly causing the antibodies in my blood now? I don’t know what kind they are, all I know is my doctor told me on a scale of 1 to 8, 8 being highest, I’m a 1. But I’m still scared for my baby.
The specialist i was referred to knew much more than my women’s doctor on anti-S. Unlike my women’s doctor, who left me dazed and confused (and scared!) regarding a foreign blood mixing with my own at some point in my life (which i didn’t buy…), the specialist said simply that since i have never had a blood transfusion, then the baby must have leaked some cells early on in my current pregnancy, which means the baby carries S which means my husband also must. MY body though, recognizing S as foreign, created antibodies against S.
I am very appreciative toward this blog and comments. It has put my mind at ease. I hope intrauterine blood transfusions are not needed for my future pregnancies, but if so, at least there is a means of resulting in healthy babies:-)
I have no idea how I developed the antibodies either. I’ve never had a blood transfusion or a miscarriage. The only way I could have got the antibodies is by a cross-placental bleed in the first few weeks of my first pregnancy. My other theory is that I could have developed them after I was born, if my mother’s and my bloods mixed. It’s true that ‘they’ don’t know much about the anti-S thing, but one reassuring thing they have told me during each of my 3 pregnancies, is that it seems fairly harmless, not like anti-D.
The MCA dopplers are pretty good at measuring for baby’s aneamia. At 32 weeks, your baby has such a high rate of survivial. There is so much the medical professionals can do for you and your baby, for example, intrauterine blood transfusions and transfusions after birth as well. I think that a titre of 1024 is very high; I don’t know how high mine got in my last pregnancy because they stopped measuring after the 2-level jump of titres, if that makes sense.
If it is any reassurance, I have given birth to three very healthy babies, with very good birth weights (actually, ranging between 7lb14-8lb14 at 2-3 weeks early!). The only dramas this anti-S caused me was, firstly, the regular testing and I was induced early with all babies, meaning that I could not go into labour naturally (possibly a good thing for me, as I labour very quickly and could end up giving birth in the car…).
BEst wishes to you during your pregnancy. I hope that things go very well for you.
hi, I’ve been hunting the net for any info about anti S. Early in my pregnancy I was found to have a phenotype S- s+. my husband was checked and we were told that his children would not inhertit the S antigen, this has confused us both, if our baby doesn’t have the antigen and I have never had a blood transfussion, then how and why have I formed the antibodies. I am now 32 weeks, my last titer was 1024, which from what info I have managed to find this is very high (it had doubled in 4 weeks). I have little confidence in the consultant I have been refered to as anything we have ask him tends to come back with ‘i don’t know’. I have a 32 week scan on Monday and they will do a MCA. I am concerned due to lack of info and due to the fact that this is my first pregnancy (at 38 years of age). Can anyone let me know where I maybe able to get more info from as I would also like to donate the cord blood and don’t know if this would now be possible.
Hi! I ran across your post after extensively searching for information on anti-S. I am 29 years old and 13 weeks pregnant with my first pregnancy. Two blood tests confirmed that i have S antibodies. I have never been around any one elses’ blood, never had a blood transfusion, and never an abortion or miscarriage (which i am 100% certain about). I became pregnant on my wedding night! I asked my doctor if it is possible that my current pregnancy caused this, and she said it was highly unlikely. However, in your post and select other postings, i see otherwise. So, it is true that your current pregnancy, early on, can cause this mixing of blood, thus producing S antibodies??? Thank you so much for any confirmation you can provide on your own personal story. It is such a mystery to me (and unnevering) how i ever became infected with a foregin blood.
~ Anna