Why I Have To Have Anti D Injections During Pregnancy

I’ve mentioned in previous pregnancy diary posts that I have to have something called Anti D injections during pregnancy. Explaining it in an already long pregnancy diary post was going to take too long so I said that I would talk about it in its own post if people were interested. A couple of people commented saying they would like to find out more about it so here goes. There are many things we never get told about pregnancy and I never realised that there was a possibility that if I got pregnant, I’d need to take specific injections throughout!

My blood type is something called rhesus negative (RhD-negative). All rhesus negative mums to be have to have an injection during their pregnancy in case the baby they are carrying has a positive rhesus status (RhD positive). This will mean there’s a mismatch between your rhesus status and your baby’s rhesus status. But what harm could a mismatch do?

During your pregnancy and your labour, there may be points when baby’s blood will mix with yours. Even if bloods don’t mix during pregnancy, they almost certainly will do during birth. Unfortunately when your body detects your baby’s blood within your own circulation, it will treat it as a foreign invader and your immune system will produce antibodies to destroy blood from your baby that it finds in your circulation. This is incredibly dangerous as your antibodies may cross the placenta and attack your baby’s blood, which can cause a condition called haemolytic disease of the newborn (HDN). This can lead to your baby developing anaemia, jaundice and sometimes may even cause brain damage in the most severe cases.

In Jack’s case, he has the same blood type as me so I needn’t have worried but I had the injections anyway as they stop your body from becoming sensitised to RhD-positive blood. Anti-D destroys any blood from your RhD-positive baby before your body has a chance to make antibodies. Whilst Jack eventually turned out to have the same blood type as me, I of course didn’t know that during pregnancy so took the necessary precautions.

Anti-D itself is made from the plasma of human blood given by donors who are screened for various diseases. Since Jack was born, you no longer have to have it as often during your pregnancy – I had it 3 or 4 times during my pregnancy with Jack however I had my one and only one for baby girl at my last midwife appointment. I’m not too sure why it has changed but maybe it is a bigger dosage?

I don’t need to worry now until my labour. Once I’ve had my baby girl, they will quickly test her blood to see if she is negative herself or positive. If negative, no further action will be taken. If positive, she will have to have her own Anti-D injection within 72 hours to prevent anything happening. I’m keeping my fingers crossed that she’s negative like me but we’ll see.

I hope this gives a slightly better understanding of why I have to have these injections throughout pregnancy. They aren’t pleasant but they are a necessity and if it keeps my baby safe, I am all for it.

Had you heard of these injections before?