Q: Hello doctor, please what will happen to an O- mother that didn’t take the Rhogam injection after delivery but took it when she was seven month pregnant?

A: Thanks for writing in. The challenge here is that of Rhesus incompatibility…the fact that the mother is O negative and it would appear the father is O positive.

Usually in pregnancy, your blood and your baby’s blood do not mix. However, during the process of delivery (and some procedures during pregnancy), some degree of mixing of mother’s and baby’s blood happens. When this occurs, if your baby is O positive, your body starts to produce antibodies against your baby’s blood….literally. But, because your baby is being delivered or has been delivered, the antibodies have very little time to do any damage to the baby. They can only get rid of the small amount of baby’s red blood cells in your own body. So, baby number 1 is not a problem.

The challenge though is that these antibodies are now waiting for another opportunity to attack foreign blood cells. If you give birth to a baby that is O negative like you, this is not a problem. If, however, the next baby is O positive, those antibodies kick in and start to attack your baby’s red blood cells. It is for this reason that the Rhogam injection is given within 72 hours of delivery to ensure that your body does not mount the regular response of producing antibodies against Rhesus O positive blood. The injection deceives your body into thinking it has already produced antibodies, thereby protecting your baby as the particles of Rhogam cannot cross the placenta.

I hope in your case, that your first pregnancy involved a Rhesus negative baby…in which case the injection you didn’t take wasn’t needed anyway. Whatever the case, I’m glad you’ve taken the injection now.

Don’t beat yourself up over the injection that you didn’t take. It’s past. Let’s focus on the present and be sure to prevent future issues like this. Your doctor already knows what complications are likely to be expected and I trust that he will have the right team in place to handle these as best he can.

If there is a case of incompatibility though and it’s severe with the baby in danger, the baby can get special blood transfusions called exchange transfusions either before birth (intrauterine fetal transfusions) or after delivery. Exchange transfusions replace the baby’s blood with blood with Rh-negative blood cells. This stabilizes the level of red blood cells and minimizes damage from Rh antibodies already in the baby’s bloodstream.

I wish you the very best.

Lots of hugs!