The objective of this study was to assess the value of Doppler indices calculated from the inferior vena cava and ductus venosus in the identification of acidemia and hypoxemia as determined by pH and gas analysis of fetal blood obtained by cordocentesis in growth-retarded fetuses. Doppler measurements were performed in the inferior vena cava and ductus venosus in 209 normally grown fetuses and in 89 growth-retarded fetuses. All growth-retarded fetuses were free from structural and chromosomal abnormalities, and uteroplacental insufficiency characterized by Doppler changes in the umbilical and middle cerebral arteries was the most likely etiology of the growth defect. In this group of fetuses, Doppler recordings were performed immediately before cordocentesis. Ten different indices were calculated from venous velocity waveforms, and reference limits for gestation were constructed by the cross-sectional analysis of data from normally grown fetuses. Logistic regression and receiver operator characteristic curve analysis were performed to examine the relationship between Doppler indices and acid-base status. The pre-load index (peak velocity during atrial contraction/peak velocity during systole) in the inferior vena cava was the best explanatory variable for acidemia (chi 2 = 48.33; p < or = 0.001). Hypoxemia was predicted less well by venous indices and the best results were achieved by the S/A ratio in the ductus venosus (chi 2 = 9.46; p < or = 0.005). In conclusion, our data suggest that acidosis in growth-retarded fetuses may be non-invasively identified by Doppler measurements of the inferior vena cava and that a higher efficiency can be achieved by the use of the pre-load index.

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The objective of this study was to determine whether in growth-retarded fetuses secondary to uteroplacental insufficiency the cardiac ventricles exert a force different from that of appropriately grown fetuses. Doppler echocardiographic studies were performed in 156 appropriately grown fetuses (gestational age 18-38 weeks) and in 72 growth-retarded fetuses (gestational age 24-36 weeks) free from structural and chromosomal abnormalities and characterized by Doppler changes in the umbilical artery and middle cerebral artery suggesting uteroplacental insufficiency as the most likely etiology of the growth defect. Right and left ventricular ejection force values were calculated from velocity waveforms recorded at the level of aortic and pulmonary valves, according to Newton's second law of motion. In appropriately grown fetuses, left and right ventricular ejection force values significantly increased with advancing gestation and the two ventricles exerted similar force. In growth-retarded fetuses, the ventricular ejection force was significantly and symmetrically decreased in both ventricles. Among growth-retarded fetuses, a poorer perinatal outcome was observed in those fetuses in which the ejection force of both ventricles was below the 5th centile of the normal limits for gestation. In 12 growth-retarded fetuses followed longitudinally during the last week preceding intrauterine death or Cesarean section due to antepartum heart-rate late decelerations, a significant decrease of ejection force was found in both ventricles. Finally, a significant relationship was found between the severity of acidosis and right and left ventricular ejection force values in 22 fetuses in which Doppler recordings were performed immediately before cordocentesis.(ABSTRACT TRUNCATED AT 250 WORDS)

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Objective To assess the value of Doppler indices, calculated from fetal arterial peripheral vessels, cardiac outflow tracts and venous vessels, in the identification of acidaemia, hypercapnia and hypoxaemia as determined by pH and gas analysis of fetal blood obtained by cordocentesis in growth retarded fetuses. Design Doppler measurements were taken from umbilical artery, thoracic descending aorta, renal artery, middle cerebral artery, cardiac outflow tracts, inferior vena cava and ductus venoms immediately before cordocentesis. Logistic regression and receiver‐operator characteristic curve analysis were performed to examine the relation between Doppler indices and acid‐base status. Setting Tertiary centre for fetal medicine. Subjects Forty‐eight growth retarded fetuses fulfilling these criteria for inclusion: 1. absence of chromosomal and structural anomalies; 2. an abdominal circumference or ultrasonographic estimated fetal weight less than the 5th centile; 3. presence of abnormal velocity waveforms in umbilical artery; and 4. postnatal confirmation of a birthweight below the 5th centile and absence of structural anomalies. Results The percentage of reverse flow in inferior vena cava was a more closely related variable for acidaemia (x2= 29.69; P≤ 0.001) and hypercapnia (x2= 12.86; P≤ 0.001) than the other Doppler indices. Hypoxaemia was better predicted by the pulsatility index from middle cerebral artery (χ2= 15.31; P ≤ 0.001). Conclusion The analysis of velocity waveforms from inferior vena cava and middle cerebral artery can be used to predict acid‐base status in growth retarded fetuses secondary to placental insufficiency. This may lead to a more accurate antepartum monitoring of such fetuses.

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There is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice.