The Rh Factor: How It Can Affect Your Pregnancy

Rh Factor (Rhesus Factor)

A certain type of protein found outside the blood cells is called the Rhesus factor, or Rh factor. People are either Rh-positive or Rh-negative (they have the protein) (they do not have the protein).
This distinction matters primarily when your child is Rh-negative and you are Rh-positive.

What is RH factor?

Rh factor is a protein typically found outside red blood cells and is also called a rhesus factor. The protein is inherited genetically (passed down from your parents). You are Rh-positive if you have the protein. You are Rh-negative if you haven’t inherited the protein.
Around 85% of the people will be Rh-positive.

How important is the Rh factor?

This protein does not affect your health as a whole, but if you are pregnant it is important to know your Rh status. If you are Rh-negative and your child is Rh-positive, the Rh factor may cause complications during pregnancy.

Risks of incompatibility of Rh?

A woman who is Rh-negative happens to be incompatible when she is pregnant with Rh-positive baby blood. The immune system of women reacts and creates Rh antibodies with Rh incompatibility.
These antibodies help drive an attack on the baby by the immune system that the mother’s body considers a foreign object.

Blood transfusions or fetal blood enters the mother’s blood can result in the formation of antibodies:

  • Complications of early pregnancy, such as ectopic pregnancies, or miscarriages.
  • Stomach damage during pregnancy
  • Pregnancy bleeding
  • Tests require a pregnant woman to remove cells or fluids (like amniocentesis and chorus villus sampling)

Who is in danger of being incompatible with Rh?

A woman with an Rh-negative risk of becoming pregnant for Rh incompatibility. Doctors routinely do not test the status of Rh in men.

Causes and Symptoms

How does Rh incompatibility occur?

The Rh incompatibility is a consequence of a blood difference between the child and the pregnant woman. If children inherit the protein from their fathers, even when their mom is Rh-negative children can be Rh-positive.

Testing and diagnosis

How is Rh incompatibility diagnosed?

Most women are diagnosed with Rh incompatibility with simple blood tests. Your obstetrician will test you to determine if you are Rh-negative when you become pregnant.

This test is usually performed by doctors in the first quarter of your routine. If you have vaginal bleeding, it can be done earlier.

You may order another blood test called an antibody screen if you have Rh-negative blood. This test checks if Rh antibodies are present in your blood. You are at risk for Rh incompatibility when your screen returns positive.

You will receive immunoglobulin Rh (RhIg) to prevent antibody build-up. This is usually done approximately 28 weeks and 72 hours after delivery. If you have bleeding or other complications, you may receive a dose during early pregnancy.

Treatment and management

What are the complications of incompatibility with Rh?

Rh incompatibility does not affect women in pregnancy. Hemolytic anemia may occur in a baby. Hemolytic anemia leads to faster destruction of a baby’s red blood cells than replacement can be.

There are mild to severe effects of hemolytic anemia. These effects may include jaundice, heart failure, and liver failure. Doctors quickly treat this condition according to its severity.

No therapy may be required in mild cases.

A baby can be transfused through the umbilical cord in severe cases.
It helps replace the red blood cells of the baby.

Special lights can be used to treat babies that have jaundice, or a large amount of bilirubin, to reduce bilirubin levels.


Is it possible to prevent incompatibility of Rh?

Since the Rh factor is genetic, the type of Rh that your baby has cannot be selected.
However, you can prevent Rh Incompatibility by receiving RhIg at specific times during your pregnancy if you are an Rh-negative woman with an Rh-positive infant. It’s an important topic to talk to your doctor about.

Forecast Outlook

What are Rh-negative blood prospects for women?

Although Rh-negative women are not harmed by Rh-positive blood contact, RhIg injections are necessary to reduce risks to babies for future pregnancies after each contact with Rh-positive blood.

In the following events:

Pregnancy including abortion and miscarriage
Transfusions of blood
Blood or marrow transplantation
Rh-positive blood accidental needle sticks