FETAL CEREBRAL AND RENAL DOPPLER IN SMALL-FOR-GESTATIONAL-AGE FETUSES IN HYPERTENSIVE PREGNANCIES

The aim of the present work is to evaluate the hemodynamic disorders induced in several fetal vascular areas by maternal hypertension and to check the sensitivity and the specificity of the various Doppler parameters in the detection of small for gestational age (SGA) infants. The population consisted of 90 pregnant mothers aged 26.3 +/- 5.8 years with pregnancy-induced hypertension. Seventeen of them delivered moderate small for age babies (between the 10th and 5th centiles), without any neonatal complication. The opposition to flow in the fetal brain and kidney and in the placenta was evaluated using the Resistance Index (RI). The ratio of cerebral RI and umbilical RI, called the cerebroplacental ratio (CPR), was calculated and used as an indicator of fetal flow redistribution. The ability of CPR and renal RI to predict SGA at birth was evaluated; the sensitivity, specificity, positive predictive value, and negative predictive value for the CPR were 88.2%, 98.6%, 93.8% and 97.3%, respectively. The corresponding figures for the renal RI were 58.8%, 94.5%, 71.4% and 91%, respectively. Furthermore, in the SGA group, the abnormal renal RI values were both above and below the normal range, whereas the CPR values demonstrated consistent changes (always < 1). Conclusion: this investigation demonstrates that in pregnancy-induced hypertension (even with moderate growth retardation, and no neonatal complication), the diagnostic efficacy of CPR for predicting SGA at birth is very high and that of renal RI correlates very poorly with fetal growth.