Why is it important to know your Rh factor?

During pregnancy, it is common to hear about blood groups and the Rh factor. For most women, this information will not have any impact on their pregnancy. However, if your blood group is Rh negative, your healthcare team will pay special attention to this aspect.

To help you understand better, imagine your immune system is like a security guard at the door of a building. It usually recognises everything that belongs to it. But if it finds something it considers different, it can react as if it were an "intruder".

In some situations, an Rh-negative mother can come into contact with the blood cells of an Rh-positive baby. If this happens, the mother's body can produce antibodies against these cells. Usually, this does not cause problems in this pregnancy, but it can affect a future pregnancy if preventive measures are not taken.

This is precisely why, at around 28 weeks, an injection called Anti-D immunoglobulin is given to Rh-negative pregnant women. This medication prevents the body from producing these antibodies, protecting this pregnancy and, above all, future pregnancies.

After birth, the baby's blood group will also be tested (usually only in the case of Rh-negative mothers). If the baby is Rh-positive, another dose of Anti-D immunoglobulin may be needed within the first 72 hours after birth, ensuring protection for future pregnancies.