Prediction of fetal anemia by middle cerebral artery peak systolic velocity in pregnancies complicated by rhesus isoimmunization.

Abstract

OBJECTIVES:

To study the correlation of peak systolic velocity in the middle cerebral artery with hemoglobin concentration in fetuses at risk of anemia due to Rhesus isoimmunization.

DESIGN:

Peak systolic velocity of middle cerebral artery (MCA-PSV) was measured before 66 cordocentesis procedures in 20 isoimmunized fetuses. Reference values were derived from a study of 300 control fetuses. MCA-PSV values and hemoglobin concentrations were expressed as multiples of the median (MoM) for gestational age. The following hemoglobin concentration MoM thresholds defined degrees of anemia: mild, between 0.83 and 0.65; moderate, between 0.64 and 0.55; and severe, less than 0.55. Regression analysis was performed and receiver-operator-characteristic curves were constructed to determine the diagnostic accuracy of different thresholds of MCA-PSV for the prediction of moderate to severe anemia, either at the initial or repeat cordocentesis procedures.

RESULTS:

The mean (+/-SD) gestational age at cordocentesis was 28.5+/-4.6 weeks. Moderate to severe anemia was observed on 29 (44%) and hydrops on 27 (41%) occasions. MCA-PSV correlated weakly with hemoglobin concentrations. At threshold values 1.50 MoM, the sensitivity, specificity, and negative predictive value for moderate to severe anemia were 9.0, 100, and 48.0% at the initial cordocentesis procedures, and 44.0, 96.0, and 73.0% at repeat cordocentesis procedures, respectively.

CONCLUSIONS:

Although MCA-PSV is highly specific, negative values do not rule out fetal anemia. Further research is required before it can be recommended in clinical practice.

• Authors: M M Alshimmiri, M S Hamoud, E A Al-Saleh, K Y Mujaibel, J A Al-Harmi, L Thalib
• Journal: Journal of perinatology : official journal of the California Perinatal Association (J Perinatol) Vol. 23 Issue 7 Pg. 536-40 (Oct 2003) ISSN: 0743-8346 [Print] United States
• PMID: 14566348 (Publication Type: Journal Article)

Chemical References

• Hemoglobins

Topics

• Anemia (diagnosis, etiology)
• Blood Flow Velocity (physiology)
• Female
• Fetal Diseases (diagnosis, etiology)
• Hemoglobins (analysis)
• Humans
• Middle Cerebral Artery (physiopathology)
• Multivariate Analysis
• Pregnancy
• ROC Curve
• Rh Isoimmunization (complications, physiopathology)
• Systole (physiology)