Erythroblastosis Fetalis Rh Incompatibility

Overview, Causes, & Risk Factors

Rh incompatibility is a condition that occurs when the mother of afetus or newborn has Rh-negative blood type and the fetus or newborn hasRh-positive blood. This incompatible blood reaction may cause problems in anewborn as well as life-threatening problems for future pregnancies.

What is going on in the body?

The Rh factor, or rhesus factor, is a marker that may or may not be present onthe surface of a person’s red blood cells. When a woman has the Rh componentin her blood, she is considered Rh positive. When she does not have the Rhfactor, she is considered Rh negative. When a person who has Rh-negative bloodis exposed to Rh-positive blood, that person’s body does not recognize the Rhfactor and considers it something foreign. The body builds antibodies againstit as it would for any foreign substance that is introduced into the blood.

If the person who is Rh negative is ever exposed in the future to Rh-positiveblood, his or her body is armed to attack the red blood cells that have the Rhfactor. Problems may arise if a woman with Rh-negative blood conceives a babywho has Rh-positive blood. (This may occur if the father of the baby hasRh-positive blood.) The pregnant woman’s body can become sensitive to the Rhfactor and build up “antibodies” to attack the Rh factor.

The build up of antibodies does not usually occur until after delivery of thenewborn. However, not all women develop antibodies to the Rh factor afterhaving one baby with Rh-positive blood. Generally, there is no effect on thefirst-born child. If problems occur, they generally happen in second and later pregnancies.

Let’s say a woman who is Rh negative becomes pregnant again and her unborn baby has Rh-positive blood. The Rh antibodies that the woman may have developedduring or after her first pregnancy can pass through the blood to her secondbaby and attack the baby’s red blood cells. This attack can cause hemolysis,which is the destruction of red blood cells. The baby may start to produce more red blood cells in an effort to replace the ones that were destroyed.

What are the causes and risks of the disease?

Rh incompatibility occurs when a woman who has Rh-negative blood and a man who has Rh-positive blood conceive a baby who is Rh positive. There is generally no risk to the first baby, but rather to future babies who have Rh-positive blood.

Previous abortions or stillbirths of a fetus that had Rh-positive blood may present a risk to a woman who is Rh negative. This exposure to Rh-positive blood may be enough to cause her body to make antibodies to the Rh factor. Any future Rh-positive babies she may conceive may be at risk.

Symptoms & Signs

What are the signs and symptoms of the disease?

Symptoms associated with Rh incompatibility in a fetus include:

  • a decrease in fetal growth
  • decrease in movement of the fetus
  • small lungs, kidneys, and brain
  • stillbirth
  • Symptoms of Rh incompatibility in a newborn include:

  • jaundice, which is yellowing of the skin and the whites of the eyes from high levels of bilirubin
  • paleness of the baby’s skin
  • an enlarged liver and spleen
  • petechiae, or a rash that looks like little bruises
  • swelling of the tissues
  • difficulty breathing, causing grunting and rubbing noises in the lungs
  • neurological damage, such as a decreased ability to hear, see, and feel
  • seizures
  • poor muscle tone, decreased movement, and poor reflexes
  • heart problems, including heart murmurs and swelling of the heart
  • high-pitched cry
  • poor sucking ability
  • Diagnosis & Tests

    How is the disease diagnosed?

    When diagnosing Rh incompatibility, a healthcare provider will obtain a fullhistory of the mother. This should include her blood type and information about previous pregnancies and previous blood transfusions. A blood test should be done to check the mother’s blood type and to see if she has antibodies to the Rh factor. Also, the father should have a blood test done to determine his blood type and to see if he has the Rh factor.

    Tests of the amniotic fluid, the fluid that surrounds the fetus duringpregnancy, can be done to see if there are Rh antibodies.

    Tests that may be performed on a newborn include a test for Rh antibodies and a blood count from the cord blood. Scans to evaluate the function of the heart, liver, spleen,and brain may also be recommended.

    Prevention & Expectations

    What can be done to prevent the disease?

    Rh incompatibility can be prevented by giving women an injection of somethingcalled Rho immune globulin. Rh-negative women who are candidates for thistherapy include those who

  • are known to be carrying a baby that is Rh positive
  • have just given birth to an Rh-positive baby
  • have had a spontaneous abortion or elective abortion of a fetus who was Rh positive
  • It is unclear exactly how Rho immune globulin works. It is thought to preventthe woman from developing antibodies to the Rh factor. If a woman does notdevelop these antibodies, then there may be little risk to any futureRh-positive babies she may have. This therapy may be given just before a womandelivers her Rh-positive baby or immediately afterward. Some women may be given it both times if the healthcare provider feels it is necessary. This therapy is very effective in reducing the chances that a woman will have problems with future pregnancies.

    An Rh-negative woman should be tested for antibodies at the first prenatalvisit, at 24 weeks, 28 weeks, 32 weeks, and 36 weeks of her pregnancy. AllRh-positive women should be tested for antibodies if they have had blood transfusions, a baby with jaundice, a stillbirth, abortion, or problems with the placenta in the past.

    What are the long-term effects of the disease?

    The long-term effects of Rh incompatibility depend on whether the woman wasgiven Rh immune globulin or any other treatment during the pregnancy. Whensevere Rh incompatibility goes untreated, many infants die at a very early age.

    The infants that do survive may suffer from severe nerve problems includingcerebral palsy and communication\ \education, including reading, writing, and basic math\ \motor function\ \personal care, such as bathing, dressing, eating, and toileting\ \social skills\ \thinking skills, such as decision making, problem solving, and self-direction\ \working\mental retardation. Others suffer from hydrops fetalis.Hydrops fetalis causes the destruction of large amounts of red blood cells.This leads to severe anemia, or low red blood cell count. Also, these infants may have swelling of tissues and organs in the body that can lead to death. Kernicterus is another condition in which high levels of bilirubin build up in the brain. This leads to seriousbrain damage.

    What are the risks to others?

    Rh incompatibility poses a high risk for future pregnancies and fetuses if left undiagnosed and untreated. However, with early prenatal care and appropriate therapy with Rho immune globulin, the risk to women and babies during futurepregnancies is very low.

    Treatment & Monitoring

    What are the treatments for the disease?

    The main treatment for Rh incompatibility is the Rho immune globulin. It isgivenby injection to the mother at 28 weeks and at 72 hours after delivering a baby.This injection may also be given after abortions or other terminatedpregnancies.This gamma globulin, also known as RhoGam, prevents the formation of antibodiesthat may affect other pregnancies.

    Other procedures that may be necessary for treatment include:

  • planned delivery, via cesarean sectionor induced labor
  • phenobarbital given several weeks before delivery to lower the bilirubinlevel in the blood of the newborn
  • exchange transfusion, which is a blood transfusion in which fresh group 0, RH negative blood is given to an unborn fetus in exchange for his or her blood
  • infusion of albumin, a protein, to decrease bilirubin levels
  • phototherapy, a procedure in which the newborn is placed under special lights, to helpdecrease the level of bilirubin in the blood
  • Depending on the degree of Rh incompatibility, the child may need physical therapy and a ventilator, or artificial breathing machine, for breathingdifficulties.

    What are the side effects of the treatments?

    Sideeffects of medications include stomach upset, rash, and allergic reaction. Side effects of blood transfusions may include lethargy, muscle twitching,bleeding, and reaction to the blood being transfused. Many of the therapies mayinterfere with parent bonding. Encouraging parent bonding between treatmentsand making adjustments so parents can partake in care of their baby whenpossible will allow for more parent bonding.

    What happens after treatment for the disease?

    When theincompatibility is diagnosed and treated quickly, the infant may recoverquickly without further problems, or with exchange transfusion. Infants whodeveloped more severe Rh reactions and are untreated may suffer severe nerve orbrain damage, requiring life-long treatment with therapy to adjust to theworld physically, mentally, and medically.

    How is the disease monitored?

    The healthcare providershould be contacted if an infant who has been exposed to Rh incompatabilitydevelops a fever, yellowing of the skin, poor appetite, poor weight gain, orinconsolable crying.

    Article type: xmedgeneral