Objective: To compare perinatal results of Rh-alloimmunized pregnancies managed with spectrophotometric amniotic fluid analysis or fetal middle cerebral artery Doppler ultrasonographic velocimetry.
Method: A descriptive observational study involving 291 consecutive Rh-negative pregnancies. Group 1 consisted of 74 isoimmunized women managed with amniotic fluid spectrophotometry; group 2 of 25 isoimmunized women managed with Doppler ultrasonography; and group 3 of 192 nonimmunized Rh-negative women. The variables analyzed were need for intrauterine or neonatal transfusion, mode and time of delivery, birth weight, neonatal hematocrit, and perinatal mortality.
Results: Need for intrauterine transfusion, birth weight, prematurity, rate of cesarean section, and perinatal mortality were similar in groups 1 and 2. Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher when spectrophotometry rather than Doppler ultrasonographic velocimetry was used.
Conclusion: Fetuses managed with Doppler ultrasonographic velocimetry had a higher hematocrit at birth and a lesser need for neonatal transfusion, suggesting that this noninvasive method of monitoring fetal anemia is a better choice.