What is rh disease?

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Rh disease

Rh disease is a serious pregnancy problem that can affect a baby (fetus) with Rh-positive blood if the mother has Rh-negative blood. Because their blood types don't match, the mother's immune system will make antibodies that cause the fetus's red blood cells to be destroyed. This can lead to anemia, jaundice, and dangerous swelling.

Rh disease is also called hemolytic disease of the newborn or erythroblastosis fetalis.

Rh disease is the result of Rh sensitization, which causes the Rh-negative mother to make antibodies that attack the fetus's Rh-positive red blood cells. The more red blood cells are destroyed, the worse the effect on the fetus. In severe cases, the baby may die before or after birth.

Rh sensitization usually happens during childbirth, so a fetus in a first pregnancy may not have Rh disease. But each future Rh-positive fetus will be at risk, and Rh disease tends to be worse with each Rh-positive pregnancy.

In some cases, a fetus in a first pregnancy does have Rh disease. This can happen if the mother was Rh sensitized during a miscarriage, abortion, or ectopic pregnancy or because of a test that causes bleeding in the uterus during pregnancy, such as an amniocentesis or chorionic villus sampling. A blood test can show if a woman has Rh sensitization and whether her baby is at risk.

Treatment for Rh disease depends on how severe the disease is, which can be checked with regular testing throughout the pregnancy. A fetus with mild Rh disease may not need any special treatment. One who is more severely affected may need to have a blood transfusion while still in the uterus and to be delivered early.

A woman with Rh sensitization is likely to be cared for by a high-risk pregnancy specialist (perinatologist).

How can you prevent Rh disease?

If you are Rh-negative, your doctor gives you an Rh immune globulin shot (such as RhoGAM). It helps prevent your body from making the antibodies that attack your baby's red blood cells.

Timing is important. You need the shot at certain times during your pregnancy. And you need one anytime there is a chance that your baby's blood might mix with yours. That can happen with certain prenatal tests or when you have pregnancy bleeding, such as:

  • Right after any pregnancy loss, amniocentesis, or CVS testing.
  • After turning of a breech baby.
  • Before and maybe after childbirth. Your doctor gives you a shot around week 28. If your newborn is Rh-positive, you will have another shot.

What is Rh disease?

Rh disease can be a serious problem in pregnancy. It happens when substances called antibodies in the mother's blood cause red blood cells in her baby's blood to be destroyed. This can occur when the blood types of a mother and her baby do not match.

All blood has an Rh factor. This is what makes a blood type positive or negative. When you are Rh-negative, your baby may be Rh-negative or Rh-positive. If your baby has Rh-positive blood and it mixes with yours, your body will make antibodies. This is called Rh sensitization.

Most of the time, this is not a problem in a first pregnancy. But in future pregnancies, it could cause Rh disease.

A newborn with Rh disease has mild anemia and may have jaundice. In severe cases, anemia, jaundice, and swelling can be very dangerous or fatal. Some babies need to be delivered early. Some need special care in the NICU. A very sick baby will need a blood transfusion before or after birth.

Fortunately, Rh sensitization is usually easy to prevent.

That's why it's important to get your Rh status checked in your first trimester. It doesn't cause any warning signs. A blood test is the only way to know if you are Rh-sensitive or are at risk for it.

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