COLOR DOPPLER FLOW PATTERNS AND FLOW VELOCITY WAVE-FORMS OF THE INTRAPLACENTAL FETAL CIRCULATION IN GROWTH-RETARDED FETUSES

OBJECTIVE: We examined intraplacental color Doppler flow patterns and spectral Doppler flow velocity waveforms of villous arteries in pregna ncies with intrauterine growth retardation. STUDY DESIGN: A total of 1 92 uncomplicated pregnancies and 29 pregnancies with intrauterine grow th retardation between 26 and 41 weeks' gestation were examined in thi s cross-sectional study. Intraplacental color Doppler flow findings an d pulsatility indexes of umbilical and villous arteries were correlate d with the presence of intrauterine growth retardation acid multiple o utcome variables. Villous arteries were identified by their intraplace ntal color Doppler flow image, and flow velocity waveforms were obtain ed by superimposition of pulse-wave Doppler. RESULTS: (1) Intraplacent al color Doppler flow signals from two or more villous arteries were d etected in all 192 normal pregnancies but were undetectable in 8 of 29 fetuses with intrauterine growth retardation (27.6%, p < 0.0001). Abs ence of intraplacental color Doppler flow signals was associated with fetal distress in 6 of 8 cases (87.5%) and perinatal death in two case s (25.0%), compared with 3 of 21 (14.2%, p < 0.005) and 0 of 21 (not s ignificant) cases of intrauterine growth retardation with detectable i ntraplacental color Doppler flow. Median Apgar scores at 1 minute were 5 and 8 (p < 0.05), respectively, and at 5 minutes were 8 and 8 (not significant), respectively. (2) Umbilical artery flow velocity wavefor ms were abnormal (> 95th percentile) in 8 of 21 cases of intrauterine growth retardation (38.0%) with detectable intraplacental color Dopple r flow, including two cases with reversed end-diastolic flow. In contr ast, the corresponding villous artery flow velocity waveforms were abn ormal in only 1 of 21 cases (p < 0.04). CONCLUSION: (1) Failure to det ect intraplacental color Doppler flow signals is associated with intra uterine growth retardation and fetal distress. (2) Flow velocity wavef orms of detectable villous arteries are usually normal in intrauterine growth retardation, even in the presence of extremely abnormal umbili cal artery flow velocity waveforms.