Rhesus incompatibility problems can only arise when a woman’s blood is rhesus negative and her baby’s blood is rhesus positive. This in turn can only happen if the baby’s father’s blood is also rhesus positive. Generally speaking there are no problems during a woman’s first pregnancy with a baby whose blood is rhesus positive. But during childbirth, as opposed to during pregnancy, when there is potential mixing of maternal and foetal blood, the baby’s blood can sensitise the woman to rhesus positive blood and if she has a subsequent pregnancy with a rhesus positive baby there is a risk of haemolytic disease of the newborn. This occurs because the mother will have made antibodies to the rhesus positive blood of the baby, which will react much more strongly in a subsequent pregnancy.
Thankfully the anti-D injection you had immediately after having your first baby will have prevented any risk of this haemolytic disease of the newborn happening. The blood tests you have on a regular basis throughout each pregnancy will make sure there are no antibodies and that no problem exists at all.
Haemolytic disease used to be a big problem in years gone by, but thankfully with modern obstetric intervention, this is something that you can comfortably forget about.
The Medical Team