Abnormal fetal cerebral and umbilical Doppler measurements in fetuses withintrauterine growth restriction predicts the severity of perinatal morbidity

Purpose. This prospective study was performed to determine if the ratio of the middle cerebral artery (MCA) S/D ratio (ratio of peak systolic blood fl ow velocity to diastolic velocity) to the umbilical artery (UA) S/D ratio ( MCA/UA S/D ratio) predicts the degree of neonatal morbidity in fetuses susp ected of having intrauterine growth restriction (IUGR). Methods. Sixty-one fetuses were identified prospectively by sonography as h aving an estimated fetal weight below the 10th percentile for gestational a ge. The 61 fetuses underwent Doppler sonography in the third trimester and then were stratified into 3 groups based on the MCA/UA S/D ratio: group A, MCA/UA S/D ratio > 1.0 (controls; n = 37); group B, MCA/UA S/D ratio less t han or equal to 1.0 (intracerebral blood flow redistribution; n = 16); and group C, reversed or absent UA diastolic flow (n = 8). Outcome variables as sessed included gestational age at delivery, birth weight, UA pH, mode of d elivery, respiratory distress syndrome requiring intubation, and intracrani al hemorrhage. Results. The mean MCA/UA S/D ratios in groups A and B were 1.69 +/- 0.61 an d 0.59 +/- 0.24, respectively (p < 0.01). The mean gestational ages at deli very for groups A, B, and C were 34.7, 33.2, and 29.0 weeks, respectively. The mean birth weights were below the fifth percentile for age for groups B and C and significantly related to the severity of abnormal Doppler findin gs (p < 0.01) after correction for age. Mean UA pHs were 7.25 +/- 0.01, 7.1 9 +/- 0.01, and 7.14 +/- 0.13 for groups A, B, and C, respectively, with si gnificant differences between groups A and B (p < 0.05) and groups A and C (p < 0.05). Respiratory distress syndrome and intracranial hemorrhage were not associated with abnormal Doppler findings after correction for gestatio nal age. The interval between the abnormal Doppler examination and delivery (p < 0.001) and the occurrence of fetal distress requiring cesarean sectio n (p < 0.001) were significantly related to the severity of Doppler finding s. Conclusions. In fetuses with suspected IUGR, abnormal MCA/UA S/D ratios are strongly associated with low gestational age at delivery, low birth weight , and low UA pH. Abnormal MCA/UA S/D ratios are also significantly associat ed with shorter interval to delivery and the need for emergent delivery. (C ) 2001 John Wiley & Sons, Inc.