Rh Incompatibility in Pregnancy – Causes, Symptoms, Diagnosis and Treatment

What is Rh Factor?

There are four basic blood types. A, B, O, and AB. All these blood types carry a particular protein known as the Rh factor on the surface of each blood cell. However, the blood cells of a small percentage of people do not carry the Rh factor.

Rh+ refers to the presence of the Rh factor, while Rh-negative refers to its absence. As in the case of the blood group, the Rh factor is also hereditary.  One gets it from the parents.  The majority of people have Rh-positive blood.

Cause of Rh Incompatibility During Pregnancy

Once the pregnant woman has an Rh-negative blood type and her unborn baby has an Rh-positive blood type, then the pregnant woman’s body will mistake the Rh-positive protein in the blood of the unborn baby as an outside substance. The blood from the baby can get into the mother’s bloodstream, any time during pregnancy, labor, or (most probably) delivery.

If this happens, the immune system of the mother will develop antibodies against her own unborn baby’s red blood cells. These antibodies might cross the placenta to attack the baby’s red blood cells.

These antibodies, generally, do not create issues if the woman is pregnant for the first time. It is due to the fact that the baby is usually delivered before the antibodies in the blood increase.

The antibiotics stay in the woman’s body. The body will make more Rh antibodies in successive pregnancies. Therefore, Rh incompatibility tends to cause complications in the next pregnancy.

Complications Due to Rh Incompatibility

Rh incompatibility will cause hemolytic anemia in the unborn baby. This means the destruction of red blood cells happens sooner than the body’s ability to replace them. The RBC carries oxygen to different body parts. So if the red blood cells are not sufficient, the baby fails to get enough oxygen. It can cause significant problems.

• As a result of breaking down RBC, hemolytic anemia can develop. Depending on the severity of the hemolytic anemia, it can be lethal as chances of edema and heart failure increase.
• Breaking down of RBC can result in the formation of a chemical called bilirubin, which can give rise to jaundice in newborns.
• An increased amount of bilirubin after birth – hyper-bilirubinemia – can result in an enlarged liver and spleen, severe jaundice, and even can prompt cerebral palsy in some cases.

Symptoms of Rh Incompatibility That is Seen in Unborn Baby

As explained above, Rh incompatibility affects the unborn baby, and some symptoms will be seen in them. Some of the signs that show up in the baby are:

• Low muscle tone
• Symptoms of jaundice like yellowish color of the skin and the white part of the eyes
• Lethargy

Who Are at the Risk of Rh Incompatibility?

Before pregnancy, if by any chance the mother-to-be is exposed to Rh positive blood, then she is at a higher risk of Rh incompatibility. This exposure may happen:

• If the mother to be has bleeding or abdominal pain during pregnancy.
• Pregnancy which is ectopic.
• Miscarriage or even an abortion that has been induced.
• An incompatible blood transfusion.
• Using an injection whose needle had blood which was Rh-positive.
• Amniocentesis test and also chorionic villus sampling (CVS) test can expose the pregnant woman to Rh positive blood.

If the mother fails to get a RhoGam shot, she will be at risk of Rh incompatibility in her existing pregnancy and all subsequent pregnancies.

[Read: Negative Effects Of Induced Abortion]

Diagnosing Rh Incompatibility in Pregnant Women

A blood test will likely be undertaken during the first prenatal visit to check if the pregnant woman has Rh-positive or Rh-negative blood.

• If the expecting mother is Rh-negative, the doctor may ask for the father’s blood group. However, in case the father-to-be is also Rh-negative blood type, there is nothing to worry about.
• If the blood type of the father is Rh-positive and the mother is Rh-negative, then the baby can have a higher chance of being an Rh-positive blood type. Certain screening tests will help the doctor determine whether the mother to be is at any risk of Rh incompatibility.
• A positive direct Coombs test is an indication of Rh incompatibility. This test uses a blood sample to check for antibodies that are attached to the surface of your red blood cells.
• Diagnosing higher-than-normal levels of bilirubin in the infant’s blood shows Rh incompatibility.
• Signs of red blood cell destruction in the baby’s blood are signs of Rh incompatibility. Examining the size and shape of the RBC of the baby under a microscope helps to find it out.

[Read: What Prenatal Tests Are Done in The First Trimester]

Treating Rh Incompatibility

The objective of treating Rh incompatibility is to make sure that the newborn is fine. Besides, the treatment helps to reduce the risk of Rh incompatibility in subsequent pregnancies. In the case where the mother possesses a risk of developing Rh incompatibility, the doctor, along with the treatment, will closely monitor the mother and child throughout the pregnancy. The doctor may prescribe an injection called Rh immune globulin, or RhoGam.

This shot will keep the mother’s blood from making any Rh antibodies that attack the baby’s blood. In the case where a woman with  Rh-negative blood receives a RhoGam shot, it reduces the chances of her blood getting mixed with the Rh-positive type of blood.

Treatment for a baby who has hemolytic anemia will vary with respect to the severity of the condition.

For mild and moderate hemolytic anemia, the treatment involves

1. Phototherapy

Special lights are used to treat the baby in case the amount of bilirubin in their blood is not reduced.

2. Medicines

Certain medicines and supplements are given to the baby, which help the baby’s body to create RBCs.

For severe hemolytic anemia, the treatment involves:

3. Blood transfusion

Doctors may recommend a blood transfusion for the baby.

4. Inducing labor

If the baby can stand a preterm birth, the doctor induces labor and a blood transfusion is given to the baby. In this process, the newborn’s blood will be gradually removed and replaced with new blood.

Read Also: RhoGam Shot During Pregnancy – Everything You Need To Know

FAQs

1. How Does Rh Incompatibility Affect The Baby?

Rh-negative Mothers’ immune systems treat Rh-positive fetal cells as foreign. The mother’s antibodies attack fetal blood cells. These antibodies may enter the fetus through the placenta. They kill the baby’s red blood cells. The baby’s red blood cells may enlarge and rupture leading to hemolytic neonatal Rh disease. It can drop a baby’s blood count.

2. Can The Rh Factor Cause Miscarriage?

Miscarriages may be brought on by the Rh factor. When the mother’s blood type is Rh-negative and the fetus’s blood type is Rh-positive, a miscarriage may occur.

3. Can Rh-Positive Parents Have A Negative Baby?

Yes. Red blood cell antigens define Rh status. Rhesus D antigen on RBCs makes you Rh-positive or and its absence makes you Rh-negative.  Rh status is inherited from parents. Rh-positive people (85%) inherit the dominant Rhesus D antigen from their parents. Rh-negative people (15%) lack the Rhesus D antigen from either parent.  So, can two Rh-positive individuals have an Rh-negative child? The answer is yes, but only if neither parent transmits Rhesus D.