Hi. Can get a little complicated w antibodies, is this the first time you have had antibodies detected this pregnancy? And you’ve had all your routine bloods?
If it wasn’t detected in early pregnancy, then usually the assumption would be that the pregnancy has caused it. Everybody has lots of different antigens on their red blood cells. If your baby is e antigen positive (which it could be given husband positive), and you don’t have that antigen, then your body can react to that by creating E antibodies. Over time if the antibodies increase enough, they can cross the placenta, attach to baby’s e antigen and cause the baby’s red cells to be destroyed. That can lead to anaemia. It’s not super common with E.
The specialist may offer a NIPT blood test to check baby’s blood group, depends a little on your previous results and your husband’s results, how many weeks you are when you see them etc.
Seems the most likely scenario is you will have your “antibody titre” checked. That tells you basically how many Antibodies your body has created. Above a certain level then the baby may be at risk, below that level then the baby will be fine.
If the antibody titre is high, they will do scans that can screen for anaemia in the baby. If fine, all good, if the scan is abnormal then sometimes they will consider extra treatment. It’s not common to require that if antibodies have only been detected at 32 weeks. Again - it gets complicated! The specialist will talk you through everything.
You may be familiar with “Rhesus negative or positive” and anti-d injections - the d antibody is just another example of blood antigens that people may have (the most common one).
Re your previous pregnancies being fine - this can be a common scenario, and would depend on what blood group antigens your other children have and whether your body has had a chance to make those antibodies before.
As long as you have some extra tests and monitoring as needed, then your baby will almost certainly be absolutely fine :)
Long post but hopefully that helps!