Noninvasive tests to predict fetal anemia: a study comparing Doppler and ultrasound parameters.
OBJECTIVE
This study was undertaken to compare test characteristics of ultrasound and Doppler parameters in the prediction of fetal anemia in alloimmunized pregnancies.


METHODS
In a prospective cohort study, 16 nonhydropic fetuses with red blood cell alloimmunization were evaluated with ultrasound and Doppler imaging. Middle cerebral artery (MCA) peak systolic velocity, intrahepatic umbilical venous (IHUV) maximum velocity, liver length, and spleen perimeter were measured. Results before first fetal blood sampling (FBS) or delivery were analyzed. Fetal anemia was defined as hemoglobin deficit 5 SD or greater. Sensitivity and specificity were calculated.


RESULTS
Six fetuses were anemic and required intrauterine transfusion, and 10 were not severely anemic at birth. MCA Doppler imaging was the best predictor of fetal anemia (100%), followed by IHUV (83%). Sensitivity was low for spleen perimeter (66%) and liver length (33%).


CONCLUSIONS
Doppler evaluation of MCA peak systolic velocity is better than IHUV maximum velocity, liver, or spleen size in the prediction of fetal anemia in red blood cell alloimmunization.
Fetal Medicine Unit, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
Doron
D
Dukler
Dick
D
Oepkes
Gareth
G
Seaward
Rory
R
Windrim
Greg
G
Ryan
D001805:Blood Transfusion, Intrauterine; D015331:Cohort Studies; D004899:Erythroblastosis, Fetal / Q000209:etiology* / Q000628:therapy; D005260:Female; D006801:Humans; D011247:Pregnancy; D011379:Prognosis; D011446:Prospective Studies; D012203:Rh Isoimmunization / Q000150:complications* / Q000000981:diagnostic imaging*; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal