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356 SPO Abstracts

FETAL RENAL ARTERY AND UMBILICAL ARTERY DOPPLER FLOW AND FETAL URINE OUTPUT. S.C.Mitra, U.B.Taylor, V.Ganesh, J.J.Apuzzio. Dept. of OblGyn, UMDNJ-New Jersey Medical School, Newark, NJ. OBJECTIVE: The objective of this study was to determine the correlation between the Resistance index (RI) of the umbilical artery, the RI of the fetal renal artery and hourly urine output by normal fetuses. METHODS: Doppler flow study of the fetal renal artery and the umbilical artery was performed in 95 normal fetuses between 20 and 40 weeks gestation. Color and pulse wave Doppler was used to obtained the flow velocity waveforms (FVW). RI of the flow velocity waveforms was calculated. Transverse, antero-posterior and longitudinal diameters were obtained from coronal and transverse images of the fetal urinary bladder and the bladder volume was calculated. The difference in bladder volume at 30 minute intervals was used to determine hourly urine output. Pearson's correlation coefficient and linear regression were used for statistical analysis. RESULTS: Gestational age has linear association with fetal urine output (Y= -42.63+2.13"X, p<O.Ol). The RI of the renal artery did not significantly differ with increasing gestational ages (Y=.879-1.25E-03"X, p=.22). RI of the umbilical artery decreased with an increase in gestation age (Y=.997-1.08E-02"X, p<O.Ol). The only significant correlation was between the RI of umbilical artery and the hourly urine output by the fetus (r =-.869, p<O.Ol). CONCLUSION: RI of the renal artery of the fetus did not vary with gestational age. Hourly urine output by the fetus increases with gestational age. The RI of the umbilical artery but not the RI of fetal renal artery had a significant correlation with fetal urine output.

THE IMPORTANCE OF DUCTUS VENOSUS DURING PRENATAL LIFE. C. Giorlandinox, B. Sibai*, E. Bilancionix, G. Gambuzzax, P. D'Alessiox, A. Nova*. Artemisia Medical Center, Rome, Italy. Dept. Ob/Gyn, *Univ. of Tenn, Memphis, TN. OBJECTIVE: The purpose of this study is to determine the functioning of the ductus venosus as an important organ in homeostasis in prenatal life. STUDY DESIGN: COLOR DOPPLER velocimetry was carried out on 345 pregnant women. We studied the size and velocity of the flow during pregnancy in healthy and retarded fetuses. RESULTS: Ductus venosus is the most important carrier of the flow to the heart until 24th week of gestation. After this period its importance declines progressively and the main route beconies portal and hepatic right circulation. The ductus reopens and takes on a greater significance in shunting flow directly to the fetus in different conditions. CONCLUSIONS: Ductus venosus represents one of the most Important organs In the process of maintaining good oxygenation during the first part of pregnancy. During the second part it represents the fetus' first regulatory response in maintaining its own regular oxygenation to the brain and circulatory homeostasis during different phases of behavior.

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January 1993 Am J Obstet Cynecol

LONGITUDINAL DOPPLER ULTRASOUND STUDIES OF THE UMBILICAL AND FETAL CIRCULATION IN PATIENTS THAT DEVELOP PRE·ECLAMPSIA. K Harrington~, K Hecher', B Ramsay' and S Campbell. Dept of Ob/Gyn, King's College Hospital, London. OBJECTIVE: To identify the longitudinal changes in Doppler indices of blood flow in the umbilical and fetal circulation in patients at risk of developing pre'eclampsia (PPIH). STUDY DESIGN: Prospective. serial ultrasound and Doppler assessment of patients considered to be at high risk of developing pre-eclampsia later in pregnancy. Abnormal uterine artery Doppler studies at 24 weeks (persistent notching) defined the high risk group. Serial studies (every 2 - 4 weeks) were performed on 124 high risk patients from 24 weeks. Fetal growth, liqour volume. color flow assisted Doppler studies (Pulsatility Index) of the umbilical (UA) and fetal circulation [fetal aorta (Ao) and middle cerebral artery (MeAl] were performed at each visit. The serial values of patients that developed pre-eclampsia were plotted against the normal ranges for the Doppler values and their ratios, and an analysis of variance between the last values taken prior to the onset of pre­eclampsia and the normal range was performed. RESULTS:Analysis of variance between the last UA value before diagnosis in the PPIH group showed a significant difference from normal (F"," = 8.256. p<0,02), but most of the values remained within 2 SD's of the mean. The UA/MCA PI and Ao/MCA PI ratios were also significantly different at this time (F,,6. '= 52.6, p < 0.00 11. and were more likely to be outside the normal range for these ratios. A trend analysiS will be presented, CONCLUSION:Serial measurement of the UA PI alone may not identify the compromised fetus in patients that develop PPIH. The addition of fetal Doppler studies. which indicate redistribution even prior to the clinical onset of PPIH. may give more accurate data regarding the condition of the fetus, than the UA PI alone,

FETAL PRELOAD INDEX PREDICTS FETAL HEMATOCRIT. A,. Lysjkltwlcz L.A. Bracero, N.Tejan!. Dept. OblGyn. New York Medical College, ValhaHa , NY. OBJECTIVE: To predict fetal hematocrit by determination of fetal preload Index from Inferior vena cava doppler veioclmetry, STUDY DESIGN: Fetal preload-index was obtained at 33 umbiUcal cord samplings and correlated with fetal hematocrit. Fetal preload index was calculated as "a" to ''s'' wave ratio from doppler veIocimetry of the inferior vena cava. A value of preload index above 0.4 was considered elevated and value of fetal hematocrit below 30% was considered abnormal. Sensitivity, speclftclty and predictive values of preload index In prediction of fetal hematocrit were calculated. RESULTS: The correlation coeficlent between preload Index and fetal hematocrit was 0.6. Sensitivity, specificity, positive predictive value and negative predictive value In the prediction of fetal hematocrit were 61%,95%,87% and 79% respectively. CONCLUSIONS: Fetal preload Index correlat .. with fetal hematocrit and makes this noninvasive test useful In the managment of anemic fetuses.

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