Summary about Disease
Rh incompatibility, also known as Rh disease, happens when an Rh-negative mother carries an Rh-positive fetus. The mother's immune system can react and produce antibodies against the fetal Rh-positive red blood cells. This can lead to complications for the fetus and newborn, like anemia, jaundice, brain damage, or heart failure. The severity varies, and modern treatments greatly reduce risks.
Symptoms
In the mother, Rh incompatibility usually shows no symptoms. The fetus or newborn may exhibit symptoms such as:
Anemia (pale skin, fatigue, rapid heart rate)
Jaundice (yellowing of the skin and eyes)
Hydrops fetalis (severe swelling) in severe cases - potentially fatal
Enlarged liver and spleen
Causes
Rh incompatibility occurs when:
The mother is Rh-negative (lacks the Rh D antigen on her red blood cells).
The father is Rh-positive (possesses the Rh D antigen).
The fetus inherits the Rh-positive blood type from the father.
Fetal Rh-positive blood cells enter the mother's circulation, usually during pregnancy or delivery. This can happen during:
Delivery
Miscarriage or abortion
Amniocentesis or chorionic villus sampling
Abdominal trauma during pregnancy
Ectopic pregnancy
Medicine Used
Rh immunoglobulin (RhoGAM): This is given to Rh-negative mothers during pregnancy (around 28 weeks) and after delivery (within 72 hours of delivery of an Rh-positive infant). RhoGAM prevents the mother's immune system from producing Rh antibodies.
Intrauterine transfusion: If the fetus is severely anemic, blood transfusions may be given while the baby is still in the womb.
Exchange transfusion: After birth, if the newborn has severe jaundice or anemia, exchange transfusions may be necessary to replace the infant's blood with Rh-negative blood.
Phototherapy: Used to treat jaundice in newborns.
Is Communicable
Rh incompatibility is not communicable. It's an immunological reaction between the mother's and fetus's blood types. It is not caused by an infectious agent that can be transmitted from person to person.
Precautions
Blood type testing: All pregnant women should be tested for their Rh blood type early in pregnancy.
RhoGAM administration: Rh-negative mothers should receive RhoGAM injections as prescribed by their doctor.
Monitoring during pregnancy: If antibodies are detected, the pregnancy will be closely monitored to assess the fetus's condition.
Early intervention: If the fetus is affected, timely interventions like intrauterine transfusions or early delivery may be needed.
After delivery: Monitor the newborn for jaundice and anemia and treat appropriately.
How long does an outbreak last?
Rh incompatibility is not an "outbreak". The duration of the effects depends on the severity of the fetal or newborn's condition. Antibody formation in the mother is permanent once it occurs (sensitization), which can affect future pregnancies. Jaundice in the newborn typically lasts for a few days to a couple of weeks with treatment. Anemia can persist for longer and may require ongoing monitoring.
How is it diagnosed?
Maternal blood tests:
Rh blood typing to determine if the mother is Rh-negative or Rh-positive.
Antibody screening (indirect Coombs test) to detect if the mother has developed Rh antibodies.
Antibody titer to measure the amount of Rh antibodies in the mother's blood.
Fetal monitoring:
Amniocentesis: To determine the fetal blood type and bilirubin levels (indication of red blood cell breakdown)
Doppler ultrasound: To assess blood flow in the fetal brain, indicating anemia.
Newborn blood tests:
Direct Coombs test (direct antibody test) to detect if the newborn's red blood cells are coated with maternal antibodies.
Blood type and Rh factor.
Bilirubin levels.
Hemoglobin and hematocrit to assess anemia.
Timeline of Symptoms
During Pregnancy (if severe sensitization has occurred in a previous pregnancy):
Weeks to months: Anemia and jaundice can develop in the fetus, leading to hydrops fetalis if untreated.
After Birth:
Within 24 hours: Jaundice may be noticeable.
Days to weeks: Anemia can become apparent, along with potential complications from jaundice.
Important Considerations
Prevention is key: RhoGAM is highly effective at preventing Rh sensitization.
Subsequent pregnancies: Once a mother develops Rh antibodies, future pregnancies are at higher risk. Careful monitoring and intervention are crucial.
Rare complications: While modern treatment is effective, severe cases of Rh incompatibility can still lead to fetal or newborn death.
Importance of prenatal care: Early and consistent prenatal care, including blood type testing and RhoGAM administration, is essential for preventing and managing Rh incompatibility.
Paternal blood type: Knowing the father's Rh status can help determine the risk. If the father is Rh-negative, the fetus cannot be Rh-positive, eliminating the risk.