Combined examination of middle cerebral artery and umbilical artery flow velocity waveforms in growth-retarded fetuses.

Abstract

The resistance index (RI) of middle cerebral artery (MCA) and umbilical artery (UA) flow velocity waveforms (FVWs) were characterized retrospectively in 60 growth-retarded fetuses in the third trimester of gestation. Reference ranges of MCA-RI, UA-RI, and the UA-RI/MCA-RI ratio to gestational age were obtained from a cross-sectional study of 150 healthy fetuses. Growth-retarded fetuses that developed fetal distress had lower MCA-RIs, higher UA-RIs, and higher UA-RI/MCA-RI ratios than growth-retarded fetuses that had good outcomes. The highest sensitivity for fetal distress was observed in the UA-RI/MCA-RI ratio (UA-RI/MCA-RI 94.1%, MCA-RI 79.4%, UA-RI 61.8%), and the highest specificity was in MCA-RI (MCA-RI 92.3%, UA-RI 84.6%, UA-RI/MCA-RI 76.9%). In growth-retarded fetuses, the combined examination of MCA FVWs and UA FVWs was more useful in assessing fetal well-being than examination of UA FVWs alone.