Every woman who's pregnant should get the Rhesus factor test. It's one of the first and most important tests you'll have during pregnancy.

What Is The Rhesus Factor And What Does The Test Do?

How the rhesus factor affects pregnancies
How the rhesus factor affects pregnancies

Rh factor is a type of protein on the surface of red blood cells. Your blood type has two parts: the blood-type group (A, B, O, AB) and the Rh factor. When this protein is present, your blood type is Rh-positive. And when the Rh protein is absent, your blood type is Rh-negative.

Normally, being Rh-negative has no risks. But during pregnancy, being Rh-negative can be a problem if your baby is Rh-positive. If your blood and your baby's blood mix, your body will start to make antibodies that can damage your baby's red blood cells. This could cause your baby to develop anaemia and other problems.

When Your Pregnancy Is At Risk Due To The Rhesus Factor

How the rhesus factor affects pregnancies
How the rhesus factor affects pregnancies

While the mother's and fetus's blood systems are separate, there are times when the blood from the fetus can enter into the mother's bloodstream. If this happens, the mother's immune system identifies the Rh-positive blood as an intruder and responds by making antibodies to destroy it. This response is Rh sensitization.

The antibodies in a Rh-sensitized mother can cross the placenta and attack the fetus's Rh-positive blood. These antibodies can break down and destroy the fetus's red blood cells (haemolysis), leading to anaemia. This condition is called haemolytic disease or haemolytic anemia.

In severe cases, the haemolytic disease can cause high levels of bilirubin in the blood (hyperbilirubinemia), brain damage, and even death of the fetus resulting in a miscarriage, and still birth.

Sensitization can happen during a blood transfusion, miscarriage, abortion, ectopic pregnancy, and certain procedures like amniocentesis.

The antibodies rarely cause a problem in first pregnancies. But they do not disappear, so it is very important to be screened and give an accurate medical history to your doctor or midwife.

Can Rh problems be prevented?

How the rhesus factor affects pregnancies
How the rhesus factor affects pregnancies

Yes. The goal of preventive treatment is to stop an Rh-negative woman from making Rh antibodies in the first place. You'll need to find out if you are Rh-negative early in pregnancy (or before pregnancy) and, if necessary, you will be given a medication to prevent antibodies from forming.

If you are Rh-negative and your baby is Rh-positive, try not to worry. At around 28 weeks, your doctor will give you a shot of Rh immunoglobulin (RhIG). This drug stops your body from making antibodies for the rest of your pregnancy. You may need a dose after delivery, too.

If you get pregnant again, you will need further shots of RhIG. If you have any spotting or bleeding during pregnancy, your doctor may choose to give you a shot of Rh immunoglobulin at that time as well.

Be sure to check with your doctor if you do have any spotting during pregnancy, especially if you are Rh-negative. If you already have Rh antibodies, the drug won't work. Instead, your doctor will monitor your baby's health closely. Your baby may need a blood transfusion after delivery - or sometimes while still in the womb.

What Happens After The Rh-Positive Baby Is Born With Haemolytic Anaemia?

How the rhesus factor affects pregnancies
How the rhesus factor affects pregnancies

Some babies who have the haemolytic disease will have uncomplicated pregnancies and be born at a normal gestation. Other babies will have difficulty and may have to be induced earlier.

Doctors can give blood transfusions both before and after birth for these severely affected infants. Complications associated with Rh-positive babies born to Rh-negative women include anemia, brain damage, heart failure, jaundice, stillbirth, and death after birth.

If you have questions about the Rh factor or whether or not you are in this group of women, ask your doctor or midwife for the results of your blood work.

Web MD

Also read: 6 Causes Of Bleeding In Early Pregnancy

This article was first published on AfricaParent.com