3 May 2017
 Categories: , Blog

While a mother's body does an excellent job of protecting her unborn child, there are some problems that can harm your baby from within the body. One such illness is rhesus disease, which can occur when a mother's rhesus factor differs from her baby's father's. Here's what you need to know to ensure that your unborn baby is protected from rhesus disease.

What is the Rhesus Factor?

To understand rhesus disease, you first have to understand blood groups. Most people are aware of the ABO blood group: you can have A, B, O or AB blood. However, many are unaware of Rh blood group and its importance. Rh is short for rhesus; everyone's blood type is either rhesus positive (O+, A+, B+ or AB+) or rhesus negative (O-, A-, B- or AB-). This is known as the rhesus (or Rh) factor. Knowing your Rh factor during pregnancy is important, because it can have an effect on the health of your unborn child.

What is Rhesus Disease?

Rhesus disease is a result of rhesus sensitisation. Sensitisation occurs when a woman with Rh negative blood (the rarer type) gets pregnant with the child of a man with Rh positive blood. The mother's body will see the Rh positive blood as an invasive substance that needs to be fought off with antibodies.

If this is your first pregnancy, rhesus sensitisation is unlikely to cause your baby any harm. However, if this is your second pregnancy with a Rh positive father, these antibodies will be produced rapidly and can cross through your placenta and attack your baby's blood cells. This is known as rhesus disease, and it can cause your baby to become anaemic and jaundiced. When left untreated, rhesus disease can lead to serious complications.

How Can It Be Prevented?

The best way to avoid such complications is to prevent your baby from every getting rhesus disease. Thankfully, this is easy with good antenatal care. Remember to book an appointment with an antenatal health care clinic as soon as you know you're pregnant. Your clinic will be able to offer you blood screening tests to find out whether you're rhesus negative and therefore at risk of sensitisation.

If you're Rh positive, there is no risk of rhesus disease, even if your baby's father is Rh negative. If your blood type is negative, your clinic will be able to offer you regular anti-D immunoglobulin injections which will protect you from sensitisation.

These injections need to be given during your first pregnancy. If this is your second pregnancy and you've already been sensitised, this means your body has already developed antibodies. In this case, your antenatal clinic will monitor your baby during your pregnancy and your baby's first few months to ensure that any signs of rhesus disease are treated with a blood transfusion, phototherapy, or intravenous immunoglobin therapy.