Maternal Isoimmunization-Associated Fetal Anemia After First-Trimester Abortion: A Case Report and Literature Review

Isoimmunization and fetal anemia pose considerable challenges in obstetrics, especially when there is a documented history of RhD incompatibility or other antibodies that may threaten fetal well-being. These conditions frequently result in serious complications, including hydrops fetalis, fetal anemia, and, in certain situations, fetal loss. Effective management of such pregnancies needs careful monitoring and prompt interventions, such as intrauterine transfusion (IUT), along with thorough post-delivery follow-up to safeguard both maternal and neonatal health. Due to ongoing uncertainties concerning the administration of Rh immunoglobulin (RhIg) in RhD-negative mothers during the first trimester of pregnancy, specifically before 12 weeks of gestation, this rare case series examines two pregnancies complicated by fetal anemia and isoimmunization, emphasizing the clinical trajectory, management approaches, and outcomes for the neonates involved. This presentation discusses two cases of Rh isoimmunized pregnant women with significant histories of early pregnancy loss. The first patient, a 27-year-old G3Ab2 woman, had experienced two previous miscarriages-one at 9 weeks induced pharmacologically and another spontaneous abortion at 8 weeks without curettage. She underwent her first intrauterine transfusion (IUT) at 21 weeks and 2 days with an Anti-D titer of 1:512 and a fetal hemoglobin level of 9.2 mg/dL. A total of two IUTs were performed, and she delivered a healthy neonate at term with normal Apgar and growth. The second patient, a 32-year-old G2Ab1 woman, had one prior medically induced abortion at 7 weeks using misoprostol, with no surgical intervention. She received her first IUT at 24 weeks and 5 days, with a lower anti-D titer of 1:164 and a fetal hemoglobin level of 5.1 mg/dL. Despite requiring four transfusions, she delivered at 37 + 1 weeks a healthy neonate with normal development. In the first case, the newborn presented with a bilirubin concentration 7.2 and exhibited positive results for anti-D and anti-C antibodies, both at elevated titers. In the subsequent case, the infant had a birth weight of 3 kg, normal Apgar scores, and a hemoglobin level of 10.1. Upon discharge, the infant was reported to be in stable condition and demonstrated normal growth and development at 37 months of age. The management of abortions occurring before 12 weeks of gestation in women with a negative RhD and fetuses with a positive RhD is crucial for the prevention of isoimmunization. Therefore, it seems reasonable to administer RhIg in abortions under 12 weeks to prevent future consequences.