Isoinmunización Rh en bajas respondedoras: Reporte de caso

Introduction: Rh isoimmunization consists in the production of maternal antibodies in a Rh-negative pregnant woman against fetal Rh-positive erythrocyte antigens caused by fetomaternal hemorrhage. In the pregnant population, 15% are Rh negative and the severity of fetal involvement is related to a series of immunological processes and the obstetric history. The aim of this article is to describe, the characteristics of how the subgroup of pregnant patients with low Rh isoimmunization responders could present. Case presentation: G9P5C1A2Gem1V7, 43 years old, referred at week 30 of gestation due to Rh negative isoimmunization, who did not receive Anti D immunoglobulin during this pregnancy, not in previous pregnancies or in the postpartum, with indirect coombs in ¼ that increases to 1/16, normal ultrasound follow-up. During week 35.3 presents mild fetal anemia and because it is a near term pregnancy, it is terminated by cesarean section. Newborn with adequate weight for gestational age, who was discharged at 72 hours postpartum with satisfactory evolution. Discussion: Pregnant women with low Rh isoimmunization responders become sensitized with high blood volumes without inuterous hemodynamic repercussions, producing mild hemolytic disease of newborn. This immune response is rare and is associated with protective factors, however, more studies are needed to support this condition. Conclusions: Prenatal control and serial quantitative indirect Coombs' test are the main tools for the prevention of this condition. Knowledge of the immunological response allows the identification of the subgroup of hypo responders who have a milder clinical course and less neonatal morbidity.