A comparison between middle cerebral artery peak systolic velocity and amniotic fluid optical density at 450 nm in the prediction of fetal anemia.
OBJECTIVE
The purpose of this study was to compare fetal middle cerebral artery peak systolic velocity with amniotic fluid delta optical density at 450 nm in the prediction of fetal anemia.


METHODS
A prospective study that involved 28 singleton pregnancies that were at-risk for fetal anemia was carried out in a tertiary teaching hospital. Middle cerebral artery peak systolic velocity was measured immediately before the determination of deltaoptical density at 450 nm and fetal hemoglobin concentration. Sensitivities and predictive values for fetal anemia were examined.


RESULTS
Fetal hemoglobin concentrations correlated significantly with middle cerebral artery peak systolic velocity (correlation coefficient, -0.77; P <.0001) and deltaoptical density at 450 nm zones (correlation coefficient, -0.56; P =.0025). Middle cerebral artery peak systolic velocity was >1.5 multiples of the median in 15 of 28 cases (54%); for this cutoff value, the sensitivity and positive-predictive values for a hemoglobin deficit of >-3SD were 75% and 60% and for a hemoglobin deficit of >-5SD were 100% and 47%, respectively. The corresponding values for deltaoptical density at 450-nm zone III (6/28 cases, 21%) were 0% (hemoglobin deficit, <-3SD) and 86% and 100% (hemoglobin deficit, <-5SD).


CONCLUSIONS
Middle cerebral artery peak systolic velocity and amniotic fluid optical density at 450 nm are both useful in the prediction of fetal anemia. However, Doppler examination has the advantage of being a noninvasive method that can help reduce the number of invasive procedures in pregnancies that are at-risk for fetal anemia.
Nishie
Estela N
EN
Department of Obstetrics, Hospital das Clínicas, São Paulo University Medical School, São Paulo, Brazil.
Brizot
Maria L
ML
Liao
Adolfo W
AW
Carvalho
Mario H b
MH
Toma
Oswaldo
O
Zugaib
Marcelo
M
D000328:Adult; D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry*; D000740:Anemia / Q000175:diagnosis*; D001783:Blood Flow Velocity; D017218:Cordocentesis; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005315:Fetal Diseases / Q000175:diagnosis*; D005865:Gestational Age; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D020768:Middle Cerebral Artery / Q000503:physiopathology*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013599:Systole; D018617:Ultrasonography, Doppler, Pulsed; D016216:Ultrasonography, Prenatal
D006454:Hemoglobins