Doppler velocimetry in pregnant patients with sickle cell anemia

Women with sickle cell anemia have an increased risk of bearing low-birth-weight (LBW) progeny. To establish prognostic indicators of neonatal outcome, 15 women with sickle cell anemia were followed through their pregnancies with the use of umbilical and uterine Doppler flow velocimetry. The systolic/diastolic ratios obtained were correlated with neonatal birth weight, gestational age, and birth weight percentile. Pregravid hemoglobin levels, reticulocyte counts, dense cell numbers, percentage hemoglobin F, and indirect bilirubin and lactate dehydrogenase levels were also determined, and statistical analysis was performed to assess whether any of these parameters would be useful in conjunction with velocimetry. We report here that, in sickle cell anemia, prenatal umbilical and uterine Doppler velocimetry ratios correlate inversely and significantly with neonatal birth weight (P < 0.005 and P < 0.002, respectively). In addition, prenatal maternal HbF levels also correlate significantly with Doppler velocimetry readings, an independent indicator of LBW progeny. Neither pregravid hemoglobin levels nor dense cell concentration correlates with Doppler umbilical and uterine flow velocimetry ratios determined during pregnancy. Pregravid high levels of HbF and velocimetry readings may serve to delineate a subset of sickle cell patients who may have different requirements for prenatal care. The possible mechanism for the detrimental effects of increased levels of fetal hemoglobin has not been clearly established, but it may involve increased propensity for vasoocclusion due to the unique rheology of the human placenta.