Doppler assessment of the fetal cerebral hemodynamic response to moderate or severe maternal anemia.

Abstract

The purpose of this study was to evaluate the fetal vascular adaptation to moderate and severe maternal anemia. Biometry; amniotic fluid index; uterine, cerebral, and umbilical Doppler; and maternal hemoglobin level were measured at admission and 8 days after treatment. Group 1 consisted of 16 pregnancies (maternal hemoglobin level, 6.9 +/- 0.6 g/100 mL); group 2 consisted of 23 pregnancies (maternal hemoglobin level, 5 +/- 0.6 g/100 mL). At admission the cerebral and cerebral/umbilical Doppler indexes, amniotic index, and biometry were lower in group 2. The uterine index was normal in both groups. An abnormal fetal heart rate was found in group 2 only (48%). At day 8, maternal hemoglobin level and amniotic index increased more in group 2 than in group 1. The cerebral index and the cerebral-to-umbilical resistance ratio increased only in group 2. The abnormal fetal heart rate disappeared in group 2. Only severe maternal anemia (maternal hemoglobin level, <6 mg/L) triggered fetal cerebral vasodilation and reduced amniotic volume.