The Rh factor is a protein on red blood cells that is part of one’s blood type. It is either positive or negative, and both are normal. Women who are Rh-positive are not at risk of Rh disease. However, when an Rh-negative mother is exposed to blood that is Rh-positive, most often through pregnancy with an Rh-positive child, her immune system mistakes this as an invader. This can lead to the child’s blood cells being destroyed.
Because it takes time for the immune system to respond to the Rh-positive blood cells, a mother’s first pregnancy with an Rh-positive child is unlikely to be affected. However, subsequent pregnancies are at increased risk.
Additionally, anything that exposes a mother to Rh-positive blood increases the risk of Rh disease. This includes:
- Ectopic pregnancy
- Trauma to the abdomen
- Procedures such as amniocentesis
- Blood transfusion
- Needle sticks
- Bone marrow transplantation
In newborns, these vary depending on the severity of the Rh disease and include:
- Yellowing of the child’s skin and/or eyes (i.e., jaundice)
- Decreased muscle strength
- Rapid pulse and breathing
- Enlarged organs (heart, spleen, liver)
- Brain damage
Your health care provider may order blood tests and other diagnostic tests to diagnose Rh disease. These include:
- Blood typing: This blood test determines if you are Rh-positive or Rh-negative.
- Antibody testing: This blood test determines if your immune system is already sensitized and is likely to attack the child’s blood cells.
- Genetic testing: This blood test during pregnancy determines the fetus’s blood type.
- Ultrasound: This imaging test can see if the fetus is affected by Rh disease.
- Amniocentesis: This test of the fluid surrounding the fetus can see if the fetus is affected by Rh disease.
If a mother is known to be at risk for Rh disease, a health care provider can use a prescription medication called anti-D (Rh) immunoglobulin. This injection is typically given twice during the pregnancy to prevent the mother’s immune system from attacking the child’s blood cells. One injection is typically at the 28-week mark of pregnancy and the other is shortly after the child’s birth. It may be given earlier in pregnancy or more than twice if there are any extra risk factors. This medication is very well tolerated.
However, this medication only works if the mother has not yet become sensitized to the Rh factor.
Treatment for Rh disease focuses on protecting the child from harm both during pregnancy and after birth. Treatment can include the following:
- Blood transfusion: The baby may need additional blood after birth.
- Supplements: The baby may need supplements, such as iron, to increase the amount of blood cells they make.
- Induction of pregnancy: If the Rh disease is severe, the health care provider may need to deliver the baby early.
- Phototherapy: Placing the newborn under special lights after birth can help rid the baby of dangerous toxins from the damaged blood cells.
Patient FAQ List
Rh disease, or Rh incompatibility, is a genetic condition that occurs when a mother’s blood type is different from her child’s.
Rh disease, or Rh incompatibility, occurs when the mother’s body attacks the blood cells within the developing fetus because their blood types are different. This can harm the child during pregnancy and/or after delivery.
The mother’s immune system considers the baby’s blood cells, which have a different blood type, as foreign. Therefore, the mother’s body becomes “sensitized” to those different blood cells and produces a protein called an “antibody”. These antibodies can then potentially destroy the child’s blood cells.
Mothers who have a blood type called “Rh-negative” are at risk if they are pregnant with a child with the Rh-positive blood type. This risk of Rh disease goes up after each pregnancy, after ectopic pregnancy, abortion, or miscarriage, and after certain tests done during pregnancy, such as amniocentesis.
A mother can become “sensitized” to the different blood type due to blood transfusion, bone marrow transplantation, or through an accidental needle stick injury.
A simple blood test can check for your Rh type. It is either positive or negative, and both are considered normal. However, only Rh-negative mothers are at risk for this disease.
The symptoms of Rh disease can be very different depending on how severe the disease is. It can cause jaundice, where the fetus’ or newborn’s skin and eyes turn yellow. It can also cause anemia, which is when the child doesn’t have the normal amount of blood cells because the mother’s body is destroying them. In severe cases, it can even cause brain damage, heart failure, and death.
If you know that you are Rh-negative, or have had a prior pregnancy affected by Rh disease, you may be at risk for Rh disease. Your doctor may want to do an antibody test; this blood test measures whether or not your body has already made an antibody to the Rh blood group. Additionally, they may do an amniocentesis, to collect a sample of the fluid that surrounds the fetus. They may also do an ultrasound during pregnancy or test the DNA of the baby by another type of blood test.
They may test the biological father’s blood type to determine whether the child may be at risk.
No. Rh disease is due to a genetic difference in blood type between you and your partner, and your Rh type is entirely inherited from your parents.
As the parent, aside from complications from a potential miscarriage, there is little or no risk to you. The risk is primarily to the child.
Treatment mainly focuses on prevention. If a mother is at risk, then a drug called Rh immunoglobulin will be used. It is a shot, typically given twice during pregnancy, which can help prevent harm to the baby. However, it only works if the mother’s body has not already begun attacking the child’s blood cells.
It is given once at about 28 weeks of pregnancy (6.5 months), and again shortly after the birth of the baby (within 72 hours). It may also need to be given during pregnancy in case of bleeding, trauma, miscarriage, ectopic pregnancy, abortion, or invasive procedures, like amniocentesis or fetal blood sampling.
If the mother has already been sensitized, then prevention with Rh immunoglobulin will not work. Instead, treatment will depend on the severity of the Rh disease. Mild cases may only require simple monitoring. However, more severe cases may require additional treatment, which can include blood transfusion, supplements to help the baby produce more blood cells, and early delivery.
Because it takes the body some time to complete the process of creating antibodies against Rh-positive blood cells, the first pregnancy of an Rh-negative woman with an Rh-positive child is not likely to lead to Rh disease. However, future pregnancies with an Rh-positive child are at increasing risk.