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Rh blood type mismatch between mother and fetus is highly dangerous, capable of causing repeated miscarriages or leading to hemolytic disease in newborns. It's crucial for pregnant women to determine their blood type for appropriate management.
Blood types vary among individuals due to the presence of specific proteins on the surface of red blood cells, categorized into four groups: A, B, AB, O.
Blood groups are further distinguished by the presence of additional proteins, including the Rh factor. You're Rh(+) if you have this protein, and Rh(-) if you do not.
Rh Blood Type Incompatibility
The majority, about 85%, are Rh(+). However, complications can arise for the child if an Rh(-) mother conceives with an Rh(+) father. In such cases, there's a 50% chance the child inherits Rh(+) blood from the father, developing in an Rh(-) environment.
During the first pregnancy, most babies are born healthy as Rh factor incompatibility typically doesn't pose issues. The baby's blood usually doesn't mix with the mother's during pregnancy. However, during delivery, the mother's and baby's blood can mix, leading the mother's body to encounter the Rh factor for the first time, treating it as an antigen and starting to produce antibodies against it.
Rh(-) mothers can also be exposed to the Rh factor and stimulated to produce Rh antibodies if they receive Rh(+) blood transfusions, which can lead to miscarriage or ectopic pregnancy.
In subsequent pregnancies, Rh antibodies in the mother's blood can affect the baby if the mother is pregnant again with an Rh(+) child. The re-exposure to the antigen stimulates the production of more antibodies, strong enough to cause a more severe immune reaction, leading to Rh incompatibility in the second baby. These maternal antibodies can cross the placenta and attack the baby's red blood cells, causing hemolytic anemia, jaundice, and in severe cases, heart failure or liver failure. This condition is known as hemolytic disease of the newborn.
If the mother previously received Rh(+) blood, experienced a miscarriage, abortion, ectopic pregnancy, underwent procedures (like amniocentesis), or had extensive placental bleeding in conditions like preeclampsia, there's a risk of maternal-fetal blood exchange if the fetus is Rh(+), potentially causing severe Rh incompatibility even in the first pregnancy.
How does it affect the newborn?
Newborns with Rh blood type incompatibility can experience symptoms ranging from mild to severe, potentially leading to death due to complications from hemolytic disease and kernicterus.
- Hydrops fetalis: A severe condition where the newborn experiences immediate jaundice, enlarged liver and spleen, widespread swelling, severe anemia, and heart failure. This rare form often results in death shortly after birth.
- Early-onset jaundice: Newborns develop jaundice within the first 24 hours after birth. This is the most common form, characterized by anemia and potentially an enlarged spleen.
In both conditions, neonatal jaundice can lead to kernicterus (thermal instability, decreased muscle tone, seizures, coma, etc.) if untreated, causing death or long-term neurological damage (cerebral palsy, blindness, deafness).
3. Treatment.
- Pregnant women with Rh(-) blood type must be monitored for Rh antibody levels and undergo prenatal ultrasounds to detect fetal anemia early.
- During prenatal care, preventive measures against antibody production in Rh(-) pregnant women should be taken, along with ultrasound monitoring to early detect signs of fetal anemia.
- In cases where maternal blood has high levels of antibodies and significant fetal anemia is detected, an Rh(-) blood transfusion through the umbilical cord is performed after 18 weeks of pregnancy. This risky procedure is avoided in very early gestation, with some opting for early delivery followed by postnatal transfusion.
- Immediate postnatal blood exchange within the first 24 hours is the specific and effective treatment. Without it, the infant risks rapid death from severe anemia and kernicterus.
- Treatment also includes phototherapy to prevent complications associated with kernicterus.
4. Recommendations for Monitoring and Prevention
- All pregnant women must have their blood type tested. If Rh(-), antibody screening is crucial within the first 12 weeks of prenatal visits.
- Testing the father's blood type. If the father is also Rh(-), the child will definitively be Rh(-).
- Women who have experienced miscarriages or stillbirths must have their blood group checked and monitored in subsequent pregnancies.
- Mother's antibody levels should be tested at weeks 12, 28, and 36 of pregnancy during prenatal care. If antibodies are detected, more frequent monitoring is required. Postpartum maternal blood should be tested for antibodies and fetal cell screening.
- Post-delivery, the newborn's umbilical cord blood should be tested for blood group, hemoglobin, direct Coombs, and serum bilirubin. Timely treatment should be initiated if jaundice is present.
- It's crucial to administer anti-D within 72 hours postpartum to Rh(-) mothers with Rh(+) babies. This practice is extremely important after the mother is discharged from the hospital.
- In cases of neonatal death or stillbirth, umbilical cord blood must be collected for routine tests, noting the baby's weight, jaundice status, congenital abnormalities, and the placenta's condition and weight.
- Blood samples from the mother should be taken to determine antibody presence at 6 months postpartum and again at the onset of any subsequent pregnancy. Prevention is considered successful if no antibodies are detected in these two tests.
- Future preventive measure: Administering anti-D to newborn girls with Rh(-) where the mother is Rh(+). This strategy can prevent Rh immunization due to maternal-fetal blood transmission.
Source- FB: yhoccongdong
