Fetal heart rate pattern reflecting the severity of placental abruption

Objective To identify fetal heart rate (FHR) patterns reflecting the severity of placental abruption, and to determine the incidence of normal FHR pattern in cases of placental abruption. Materials and methods We analyzed FHR tracings from 40 pregnant Japanese women with placental abruption. We analyzed which FHR patterns appeared more frequently in cases of low 5-min Apgar score, low cord arterial pH, and large separation. Results Eight out of 40 cases showed a normal FHR pattern, while 32 cases did not show a normal FHR pattern. Undetectable variability and bradycardia appeared more frequently in cases with 5-min Apgar < 7, with cord blood pH < 7.1, and with larger placental separation than in cases without these features. The normal FHR pattern was associated with 5-min Apgar >= 7, cord blood pH >= 7.1, and separation of < 25%. Conclusion Fetal heart rate pattern reflected the severity of placental abruption. Undetectable variability and bradycardia occurred significantly more frequently in cases of severe placental abruption, and thus may reflect the severity of placental abruption.