Better testing protocols could prevent RhRh factor A protein or antigen found on red blood cells. When an Rh-negative mother carries an Rh-positive fetus, her immune system may make antibodies that attack the fetus' red blood cells. isoimmunization and improve outcomes in hemolytic disease of the fetus and newborn (HDFN), according to a study published recently in the International Journal of Reproduction, Contraception, Obstetrics and Gynecology.
This new study from Bangladesh found that newborns of Rh-negativeRh-Negative A blood type trait that means your red blood cells lack the Rh(D) antigen. mothers who became isoimmunized had significantly worse blood counts and more complications than those born to Rh-negative mothers without isoimmunization.
The study, conducted at Mymensingh Medical College Hospital, examined 80 Rh-negative pregnant women between July and December 2019. Five of these women were isoimmunized, meaning they had developed antibodiesAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens. against Rh-positiveRh-Positive A blood type trait that means your red blood cells have the Rh(D) antigen. blood cells, which can attack the fetus’s red blood cells. The rest of the women in the study were not isoimmunized.
“Rh isoimmunization remains a significant cause of neonatal morbidity in Rh-negative pregnancies, shown by anemiaAnemia A condition that occurs when the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues. In HDFN, anemia occurs when maternal antibodies destroy fetal red blood cells., hyperbilirubinemiaHyperbilirubinemia A common cause of jaundice, this refers to higher than normal bilirubin levels in the blood., and increased treatment needs,” explained this study’s authors. They continued, “This study highlights the need for enhanced antenatal care with universal anti-D prophylaxis and improved fetal monitoring to manage hemolytic disease effectively.”
Read more about HDFN causes and risk factors
Results showed that 60% of the babies from isoimmunized pregnancies had hemoglobin levels below 12 g/dL, indicating anemia. None of the non-isoimmunized babies had such low levels. In addition, 80% of the affected babies had bilirubinBilirubin A yellow substance produced when red blood cells break down. High bilirubin levels in newborns with HDFN can cause jaundice or, in severe cases, brain damage. levels at or above 4 mg/dL, a sign of excessive red blood cell breakdown and a risk factor for brain damage if left untreated. All tested babies from isoimmunized mothers were positive on the direct Coombs testDirect antiglobulin test A blood test used to detect antibodies attached to red blood cells. It helps confirm HDFN in newborns., confirming immune-related hemolysis.
Treatment needs were also higher. Four out of five of these newborns required phototherapyPhototherapy A treatment that uses special blue light to help newborns break down bilirubin and prevent kernicterus. for jaundiceJaundice A common symptom of HDFN, jaundice is caused by excess bilirubin and is characterized by a yellow tint to the skin or eyes. and three needed an exchange transfusion, a more invasive and risky procedure. Most of the babies born to non-isoimmunized mothers required no treatment. Apgar scores at five minutes, which are a key indicator of a newborn’s health, were also lower in the isoimmunized group, with 40% scoring below 6 compared to just 12% in the non-isoimmunized group.
This study also linked poor outcomes to maternal risk factors. Most isoimmunized mothers had high gravidity, little or no prenatal care and did not receive anti-D prophylaxis, a preventive treatment widely recommended to stop Rh-negative mothers from becoming sensitizedSensitization The process by which a mother’s immune system becomes “primed” to recognize and attack fetal red blood cells carrying incompatible antigens. to Rh-positive blood.
These results, the authors stated, underscore the urgent need for improved prenatal screening, access to anti-D immunoglobulinIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus. and enhanced care for pregnant Rh-negative women to reduce the burden of HDFN and improve outcomes for affected infants.
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