Rh alloimmunization: Doppler or amniotic fluid analysis in the prediction of fetal anemia?

OBJECTIVE

Compare the results of amniocentesis and those of middle cerebral artery peak systolic velocity to detect anemic fetuses in Rh alloimmunized pregnancies.

METHOD: Descriptive observational study involving 99 consecutive Rh-negative pregnancies: 74 alloimmunized patients submitted to amniotic fluid spectrophotometry (group 1) and 25 alloimmunized cases managed with Doppler ultrasonography (group 2). Variables analyzed were the following: need for neonatal transfusion and neonatal hematocrit.

RESULT: Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher in cases managed with spectrophotometry compared to those managed with Doppler.

CONCLUSION

Infants managed with Doppler velocimetry had higher hematocrit and less need for neonatal transfusion, suggesting that this non-invasive method of monitoring fetal anemia may best preserve the neonate.