From the Guidelines
When a mother with B+ blood group and a father with A- blood group conceive a child, the primary concern is Rh incompatibility, and the mother should receive RhoGAM (Rh immunoglobulin) at 28 weeks of pregnancy and within 72 hours after delivery if the baby is Rh-positive, as this has been shown to significantly reduce the risk of hemolytic disease of the newborn 1. The fetus could inherit either blood type A or B from the father and mother respectively, and could be either Rh-positive or Rh-negative. If the baby inherits the Rh-positive factor from the mother, Rh incompatibility won't be an issue. However, if this is not the mother's first pregnancy and she was previously sensitized to Rh-positive blood, there's a risk of hemolytic disease of the newborn. To prevent this,
- the mother should receive RhoGAM (Rh immunoglobulin) at 28 weeks of pregnancy and within 72 hours after delivery if the baby is Rh-positive,
- regular prenatal care with blood type testing, antibody screening, and monitoring for signs of fetal anemia through ultrasound is essential,
- and the use of RhD immune globulin (RhIg) has been shown to reduce the burden of perinatal morbidity and mortality attributable to RhD alloimmunization 1. For ABO incompatibility, if the baby inherits blood type A from the father while the mother is type B, the mother's antibodies against type A blood could cross the placenta and attack the baby's red blood cells. This typically causes mild jaundice after birth that may require phototherapy. Most cases of blood type incompatibility can be successfully managed with proper medical care. It is also important to note that the Society of Family Planning (SFP) recommends against RhD testing and RhIg administration for spontaneous and induced abortion at <12 weeks of gestation, but this may be considered at patient request as part of a shared decision-making process 1.
From the Research
Impact of B+ Mother Blood Group with A- Father on the Fetus
- The provided studies do not directly address the impact of a B+ mother blood group with an A- father on the fetus.
- However, the studies discuss the importance of Rh blood type compatibility between the mother and the fetus to prevent hemolytic disease of the fetus and newborn (HDFN) 2, 3, 4, 5.
- HDFN can occur when an Rh-negative mother is exposed to Rh-positive red cells, leading to the development of allo-anti-D antibodies that can cross the placenta and destroy fetal red cells 5.
- The studies highlight the effectiveness of anti-D immunoglobulin prophylaxis in preventing maternal sensitization to Rh(D) and reducing the risk of HDFN 4, 5, 6.
- In the context of an A- father, the risk of HDFN would depend on the Rh blood type of the fetus, which is not directly related to the ABO blood group of the parents.
- If the fetus inherits the Rh-positive gene from the father, the mother's Rh-negative status could potentially lead to HDFN, but this would be prevented by anti-D immunoglobulin prophylaxis 4, 5.
- The B+ mother blood group is not directly relevant to the risk of HDFN, as the disease is primarily related to Rh blood type compatibility 2, 3, 4, 5, 6.