Impact of physician awareness on diagnosis of fetomaternal hemorrhage.

BACKGROUND Fetomaternal hemorrhage (FMH) is a poorly understood condition in which the placenta allows transmission of fetal whole blood to the mother. FMH can cause fetal anemia resulting in critical illness, death or lifelong disability. Ascertainment of the incidence of FMH is limited by reliance on retrospective studies that are dependent on a diagnosis of FMH being made at the time of patient presentation. OBJECTIVE To determine whether the diagnosis of FMH is made more frequently after an educational intervention to increase physician awareness of the condition. METHODS This is a retrospective cohort study of all neonates born at our institution from 1988 through 2010. The medical records of all neonates diagnosed with anemia in the first 24 h of life were reviewed. The incidence of FMH as a documented etiology of anemia was compared between infants born before and after our educational intervention. RESULTS Of 124,738 births during the study period, 572 neonates with neonatal anemia were identified. A total of 23 cases of FMH demonstrated by positive Kleihauer-Betke testing occurred in our cohort. The incidence of diagnosed FMH prior to our intervention was 22 per 1,000 anemic neonates compared to 182 per 1,000 afterwards (p < 0.001), while the incidence of neonatal anemia remained unchanged (p = 0.377). CONCLUSIONS FMH may be a significant cause of neonatal anemia. Diagnosis of FMH is highly dependent on physician awareness of the condition. Incorrect or absent diagnosis of the etiology of neonatal anemia has significant implications for our understanding of the epidemiology of FMH.