Understanding the Rh Factor in Pregnancy

What Is the Rh Factor?

The Rh factor is a protein found on the surface of red blood cells. If your blood has this protein, you are Rh-positive. If not, you are Rh-negative. Both are completely normal and have no impact on your general health—but it can affect pregnancy.

 Why Does It Matter in Pregnancy?

If an Rh-negative mother is carrying an Rh-positive baby, her immune system might see the baby's red blood cells as foreign and develop antibodies against them. This is known as Rh incompatibility.

 Possible Risks

• Usually not harmful in the first pregnancy due to limited blood mixing.
• In later pregnancies, maternal antibodies may attack the baby's red blood cells.
• Can lead to Hemolytic Disease of the Newborn (HDN), anemia, or in severe cases, heart failure in the baby.

 How Is It Prevented?

• Rh-negative mothers are given an Anti-D injection (Rh immunoglobulin) around 28 weeks of pregnancy.
• Another dose is given within 72 hours after birth if the baby is Rh-positive.
• This prevents the mother from developing antibodies that could affect future pregnancies.