Fetal erythroblastosis: what it is, why it happens and how to avoid it

Fetal erythroblastosis, also known as hemolytic disease of the newborn or Rhesus disease, is an alteration that usually occurs in the baby of a second pregnancy, when the pregnant woman has Rh negative blood and had a baby with blood in the first pregnancy. Rh positive type, without having undergone immunoglobulin treatment.

In these cases, the mother's body, in the first pregnancy, produces antibodies that, during the second pregnancy, begin to fight the red blood cells of the new baby, eliminating them as if they were an infection. When this happens, the baby can be born with severe anemia, swelling and enlarged liver, for example.

To prevent these complications in the baby, the woman must make all consultations and prenatal examinations, since it is possible to identify the risk of fetal erythroblastosis, starting the treatment, which includes an injection with immunoglobulins to prevent the appearance of illness in the baby. Learn more about treatment to prevent fetal erythroblastosis.

Possible causes

The most frequent cases happen when the mother, who has Rh negative blood, has had a previous pregnancy in which the baby was born with Rh positive blood. This can only happen when the father's blood is Rh positive as well, so if the mother is Rh negative the obstetrician may order a blood test from the father in order to assess the risk of erythroblastosis happening.

In addition, and although it is more rare, this change can also develop when the pregnant woman received a Rh + blood transfusion at any time in her life before she became pregnant. Therefore, it is important that the obstetrician knows well the entire history of the pregnant woman.

How to prevent fetal erythroblastosis

Treatment to prevent fetal erythroblastosis consists of the injection of anti-D immunoglobulin, which can be done:

• In the 28th week of pregnancy: especially when the father is Rh + or when the first child was born with Rh + blood and the injection was not done during the first pregnancy; 3 days after delivery: it is done after a first pregnancy in which the baby is born with Rh + blood and helps to prevent the formation of antibodies that can harm a future pregnancy.

If no injection is given and the baby is at high risk of developing fetal erythroblastosis, the doctor may also try to anticipate the date of delivery, once the baby's lungs and heart are well developed.

How to identify fetal erythroblastosis

The signs and symptoms of fetal erythroblastosis can only be seen after birth and usually include severe anemia, yellowish skin and generalized swelling in the baby.

When not properly treated, the baby is at great risk of life, especially due to severe anemia caused by the disease. However, even if it survives, serious complications can arise, such as mental retardation and injuries in various parts of the brain.

Therefore, the most important thing is to know the risk of the baby developing fetal erythroblastosis even during pregnancy, making all the prenatal consultations to identify the risk and start the treatment that helps to prevent the disease.

How is the treatment done after childbirth

If the mother has not undergone treatment during pregnancy and the baby is born with erythroblastosis, the doctor may also recommend another type of treatment, which consists of replacing the baby's blood with another Rh negative. This process can be repeated for several weeks, until all of the mother's antibodies have been eliminated.

After this period of treatment, the baby ends up replacing Rh negative blood with Rh positive blood, but, at that moment, there will be no risk.