The etiology, clinical presentation, obstetrical antecedents, and outcome of pregnancies complicated by large fetomaternal hemorrhage (FMH) were reviewed by doing a MEDLINE search from 1966 to the present and manual search before 1966. One hundred thirty-four infants with FMH > 50 dl were reported in the literature. The primary variables: birth weight, gestational age, presence of sinusoidal fetal heart rate pattern, decrease or absent fetal body movements (FBM) estimated the amount of fetomaternal bleeding and the pretransfusion hemoglobin. Other variables included the condition of the infants at birth, erythroblasts, and reticulocyte blood counts at birth, as well as the year of publication. Thirty-five of the 134 cases were preterm. Twenty infants born to mothers reporting decreased or absent FBM survived. FBM was absent in 17 cases for a period ranging between 24 hours and 7 days. In this group, six infants survived, five were stillborn, and five died in the neonatal period. A sinusoidal heart rate (SHR) pattern was reported in 21 cases. A SHR pattern was associated with decreased FBM in 13 cases (39.3 percent). Fifteen cases with sinusoidal fetal heart rate pattern survived (71.4 percent). Both decreased or absent FBM and SHR patterns were reported more often in 1990 or later than before 1990 (P < .0017 and P < .008, respectively). The cause of FMH was not known in 82 percent of the cases. The most common presenting symptoms of FMH were anemia at birth (35.2 percent), decreased or absent FBM (26.8 percent), and unexpected stillbirths (12.5 percent). Seventeen intrauterine transfusions were performed in nine cases (eight survived). A negative correlation was found between pretransfusion hemoglobin and FMH (r = -0.35; P = .0019). No significant difference was found between the cases with FMH of > 200 ml or < 200 ml. Thus, decreased or absent FBM, SHR pattern, or hydrops fetalis are late signs of FMH. Other means of early detection are needed. The role of intrauterine transfusion (IUT) needs to be better defined. The inadequate outcome data indicate the need to follow infants born with large FMH into childhood to document the effect on the central nervous system.
