Ductus venosus Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 1999;21(7):371-376
DOI 10.1590/S0100-72031999000700002
Purpose: to evaluate the possible value of pulsed and color Doppler of ductus venosus blood flow in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: the ductus venosus flow velocity waveforms and the nuchal translucency (NT) thickness were obtained immediately before the chorionic villus sample in 26 pregnancies. We employed the following criteria for the suspicion of chromosomal defects: reverse or absent flow during atrial contraction and NT greater or equal to 3 mm. We calculated the sensitivity, the specificity, the negative and positive predictive value for each of the above items. Results: there were 9 chromosomal abnormalities (3 cases of trisomy 21, 2 cases of trisomy 13, 1 case of trisomy 9, 1 case of trisomy 22, 1 triploidy and 1 monosomy X). Abnormal ductus venosus flow was observed in all cases (sensitivity of 100%). In the normal fetuses (17 cases) only 1 had abnormal flow (specificity of 94%). Concerning NT, the sensitivity and the specificity were 88% and 76%, respectively. Conclusion: our preliminary results suggest that the presence of chromosomal abnormalities may be strongly suspected when an increased NT thickness is associated with an absent or reverse flow in the ductus venosus. We speculated that both methods are valid in the screening of chromosomal defects.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 1999;21(7):371-376
DOI 10.1590/S0100-72031999000700002
Purpose: to evaluate the possible value of pulsed and color Doppler of ductus venosus blood flow in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: the ductus venosus flow velocity waveforms and the nuchal translucency (NT) thickness were obtained immediately before the chorionic villus sample in 26 pregnancies. We employed the following criteria for the suspicion of chromosomal defects: reverse or absent flow during atrial contraction and NT greater or equal to 3 mm. We calculated the sensitivity, the specificity, the negative and positive predictive value for each of the above items. Results: there were 9 chromosomal abnormalities (3 cases of trisomy 21, 2 cases of trisomy 13, 1 case of trisomy 9, 1 case of trisomy 22, 1 triploidy and 1 monosomy X). Abnormal ductus venosus flow was observed in all cases (sensitivity of 100%). In the normal fetuses (17 cases) only 1 had abnormal flow (specificity of 94%). Concerning NT, the sensitivity and the specificity were 88% and 76%, respectively. Conclusion: our preliminary results suggest that the presence of chromosomal abnormalities may be strongly suspected when an increased NT thickness is associated with an absent or reverse flow in the ductus venosus. We speculated that both methods are valid in the screening of chromosomal defects.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(8):641-647
DOI 10.1590/S0100-72032004000800008
OBJECTIVE: to investigate whether it is possible to predict acidemia at birth in pregnancies with placental insufficiency using venous-arterial indices: pulsatility index for vein (PIV) of the ductus venosus (DV) over PI of the middle cerebral artery (MCA) and PIV of the DV over PI of the umbilical artery, and establish cut-off values for this prediction. PATIENTS AND METHODS: this was a prospective cross-sectional study involving forty-seven patients with placental insufficiency (umbilical artery resistance and pulsatility indices above the 95th percentile for gestational age) who were submitted to Dopplervelocimetry in the last 24 hours before delivery. All pregnancies were singleton, over 26 weeks of age and without structural or chromosome anomalies. Arterial cord blood was obtained for gasometry immediately after birth. Acidemia was defined as umbilical arterial pH < 7.20 in the absence of uterine contractions and pH < 7.15 in the presence of contractions. Metabolic or mixed acidemia at birth were considered pathological. A ROC curve was calculated for the venous-arterial indices: PIV DV/PI umbilical artery (UA) and PIV DV/PI MCA. A cut-off value was established and sensitivity, specificity, accuracy, positive and negative predictive values and positive and negative likelihood ratios were calculated. RESULTS: The DV/UA PI index was not a good predictor of acidemia at birth. The DV/MCA PI index was related to acidemia at birth (area under the curve 0,785, p = 0,004). The cut-off value was: 0,582, sensitivity 66,7%, specificity 77,1 and accuracy 74,5%. CONCLUSION: the PIV DV/PI MCA ratio is adequate for predicting acidemia at birth in pregnancies with placental insufficiency. The cut-off value was: 0,582.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(8):641-647
DOI 10.1590/S0100-72032004000800008
OBJECTIVE: to investigate whether it is possible to predict acidemia at birth in pregnancies with placental insufficiency using venous-arterial indices: pulsatility index for vein (PIV) of the ductus venosus (DV) over PI of the middle cerebral artery (MCA) and PIV of the DV over PI of the umbilical artery, and establish cut-off values for this prediction. PATIENTS AND METHODS: this was a prospective cross-sectional study involving forty-seven patients with placental insufficiency (umbilical artery resistance and pulsatility indices above the 95th percentile for gestational age) who were submitted to Dopplervelocimetry in the last 24 hours before delivery. All pregnancies were singleton, over 26 weeks of age and without structural or chromosome anomalies. Arterial cord blood was obtained for gasometry immediately after birth. Acidemia was defined as umbilical arterial pH < 7.20 in the absence of uterine contractions and pH < 7.15 in the presence of contractions. Metabolic or mixed acidemia at birth were considered pathological. A ROC curve was calculated for the venous-arterial indices: PIV DV/PI umbilical artery (UA) and PIV DV/PI MCA. A cut-off value was established and sensitivity, specificity, accuracy, positive and negative predictive values and positive and negative likelihood ratios were calculated. RESULTS: The DV/UA PI index was not a good predictor of acidemia at birth. The DV/MCA PI index was related to acidemia at birth (area under the curve 0,785, p = 0,004). The cut-off value was: 0,582, sensitivity 66,7%, specificity 77,1 and accuracy 74,5%. CONCLUSION: the PIV DV/PI MCA ratio is adequate for predicting acidemia at birth in pregnancies with placental insufficiency. The cut-off value was: 0,582.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(1):15-20
DOI 10.1590/S0100-72032004000100003
PURPOSE: to analyze the values of Doppler ultrasound for blood flow velocity in the ductus venosus between the 10th and the 14th week of gestation, during the different phases of the cardiac cycle: ventricular systole (wave S), ventricular diastole (wave D), atrial systole (wave a), and angle-independent indexes. METHODS: Doppler was used in this prospective cross-sectional study to examine 276 single pregnancies. Fetus malformations, abnormal nuchal translucency, and women with clinical pathologies were excluded. A Toshiba SSH-140 ultrasound equipment was used. The derivation of Doppler frequency spectra was carried out according to standardized measurement procedures: less than 30ºinsonation angle and 50-70 Hz high-pass filter. The ductus venosus was identified in a median sagittal and ventral plane with the presence of color aliasing due to increase in blood flow velocity. The sample volume (1-2 mm³) was placed immediately at the origin of the ductus venosus. At least three clearly and subsequent waves were available for measurement of standard values. The Levene test and the Bonferroni method were used for statistical analysis. RESULTS: increase in blood flow velocity from 29 cm/s to 37 cm/s (p=0.013) was observed during ventricular systole between the 10th and the 14th week of gestation. Similarly, increase in blood flow velocity was recorded during the ventricular diastole (from 25 cm/s to 32 cm/s, p=0.026). There were no changes in wave a, pulsatility index, and S/a ratio in this period. CONCLUSION: the reference ranges established by this study may serve as the basis for Doppler ultrasound follow-up in a normal patient population. Further studies are required to determine the validity of these parameters and, in particular, for the fetus at risk.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(1):15-20
DOI 10.1590/S0100-72032004000100003
PURPOSE: to analyze the values of Doppler ultrasound for blood flow velocity in the ductus venosus between the 10th and the 14th week of gestation, during the different phases of the cardiac cycle: ventricular systole (wave S), ventricular diastole (wave D), atrial systole (wave a), and angle-independent indexes. METHODS: Doppler was used in this prospective cross-sectional study to examine 276 single pregnancies. Fetus malformations, abnormal nuchal translucency, and women with clinical pathologies were excluded. A Toshiba SSH-140 ultrasound equipment was used. The derivation of Doppler frequency spectra was carried out according to standardized measurement procedures: less than 30ºinsonation angle and 50-70 Hz high-pass filter. The ductus venosus was identified in a median sagittal and ventral plane with the presence of color aliasing due to increase in blood flow velocity. The sample volume (1-2 mm³) was placed immediately at the origin of the ductus venosus. At least three clearly and subsequent waves were available for measurement of standard values. The Levene test and the Bonferroni method were used for statistical analysis. RESULTS: increase in blood flow velocity from 29 cm/s to 37 cm/s (p=0.013) was observed during ventricular systole between the 10th and the 14th week of gestation. Similarly, increase in blood flow velocity was recorded during the ventricular diastole (from 25 cm/s to 32 cm/s, p=0.026). There were no changes in wave a, pulsatility index, and S/a ratio in this period. CONCLUSION: the reference ranges established by this study may serve as the basis for Doppler ultrasound follow-up in a normal patient population. Further studies are required to determine the validity of these parameters and, in particular, for the fetus at risk.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(8):577-583
DOI 10.1590/S0100-72032003000800006
PURPOSE: to determine the relationship between the Doppler indices of inferior vena cava and ductus venosus and the fetal hemoglobin concentration. METHODS: a cross-sectional prospective study was performed at the "Centro de Medicina Fetal HC UFMG" from January 1998 to July 2001. Thirty-one pregnant women with isoimmunization, detected by an indirect Coombs test >1:8, underwent a protocol for the identification of fetal hemolysis. When intrauterine transfusions were indicated, the umbilical cord hemoglobin concentration was measured at the begining of the procedure. In the other cases, it was measured at delivery. Every single intrauterine transfusion preceded by Doppler flow velocity waveforms from inferior vena cava and ductus venosus was defined as one case. Hemocue® (B-Hemoglobin Photometer Hemocue AB; Angelholm, Sweden) was used to measure the fetal hemoglobin concentration. In all cases, inferior vena cava and ductus venosus Doppler examinations were performed before the collection of fetal blood samples. For the inferior vena cava Doppler, the studied indices were pulsatility index for veins (PVI), peak velocity index for veins (PVIV) and atrial/systole ratio (CA/SV ratio or preload index); for ductus venosus, PVI, PVIV and systole/atrial ratio (SV/CA ratio). The relationship between inferior vena cava and ductus venosus Doppler indices and cord blood hemoglobin concentration was obtained by simple linear regression analysis. Moreover, an association between those indices and the finding of fetal hemoglobin <10 g/dL was shown by the c² test, significant at p<0.05. RESULTS: seventy-four procedures were studied. In twenty-three cases fetal hemoglobin was below 7 g/dL. A significant negative correlation between all studied Doppler indices and fetal concentration of hemoglobin was observed (p<0.05). The highest Doppler index values were observed in severe anemic fetuses. Fetuses with cord blood hemoglobin below 10 g/dL presented inferior vena cava and ductus venosus Doppler indices over the 95 percentile for gestational age. CONCLUSIONS: Doppler flow velocity waveforms from inferior vena cava and ductus venosus may be used as a noninvasive marker of severe fetal anemia.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(8):577-583
DOI 10.1590/S0100-72032003000800006
PURPOSE: to determine the relationship between the Doppler indices of inferior vena cava and ductus venosus and the fetal hemoglobin concentration. METHODS: a cross-sectional prospective study was performed at the "Centro de Medicina Fetal HC UFMG" from January 1998 to July 2001. Thirty-one pregnant women with isoimmunization, detected by an indirect Coombs test >1:8, underwent a protocol for the identification of fetal hemolysis. When intrauterine transfusions were indicated, the umbilical cord hemoglobin concentration was measured at the begining of the procedure. In the other cases, it was measured at delivery. Every single intrauterine transfusion preceded by Doppler flow velocity waveforms from inferior vena cava and ductus venosus was defined as one case. Hemocue® (B-Hemoglobin Photometer Hemocue AB; Angelholm, Sweden) was used to measure the fetal hemoglobin concentration. In all cases, inferior vena cava and ductus venosus Doppler examinations were performed before the collection of fetal blood samples. For the inferior vena cava Doppler, the studied indices were pulsatility index for veins (PVI), peak velocity index for veins (PVIV) and atrial/systole ratio (CA/SV ratio or preload index); for ductus venosus, PVI, PVIV and systole/atrial ratio (SV/CA ratio). The relationship between inferior vena cava and ductus venosus Doppler indices and cord blood hemoglobin concentration was obtained by simple linear regression analysis. Moreover, an association between those indices and the finding of fetal hemoglobin <10 g/dL was shown by the c² test, significant at p<0.05. RESULTS: seventy-four procedures were studied. In twenty-three cases fetal hemoglobin was below 7 g/dL. A significant negative correlation between all studied Doppler indices and fetal concentration of hemoglobin was observed (p<0.05). The highest Doppler index values were observed in severe anemic fetuses. Fetuses with cord blood hemoglobin below 10 g/dL presented inferior vena cava and ductus venosus Doppler indices over the 95 percentile for gestational age. CONCLUSIONS: Doppler flow velocity waveforms from inferior vena cava and ductus venosus may be used as a noninvasive marker of severe fetal anemia.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(5):291-298
DOI 10.1590/S0100-72032001000500004
Objective: to study the value of Doppler velocimetry of the ductus venosus and of the umbilical artery and vein, in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Patients and Methods: a total of 314 fetuses were studied consecutively. In 112 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 202 cases the postnatal phenotype was used as a basis for the result. In addition to the routine ultrasonographic examination, all the fetuses were submitted to measurement of the nuchal translucency thickness and to Doppler velocimetry of the umbilical artery and vein, particularly of the ductus venosus. For statistical analysis the Fisher exact test and the Mann-Whitney test were used. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, the ductus venosus blood flow during atrial contraction was absent (1 case) and reverse (22 cases), sensitivity was 92%. In the group of normal fetuses (289 cases), 6 evaluations demonstrated alterations in the Doppler of the ductus venosus (specificity of 97.6%, positive and negative predictive values of 76.7% and 93.3%, respectively); the false-positive rate was 2.4%. In reference to the umbilical vein and umbilical artery, there was no statistically significant difference between the abnormal and the normal group. Conclusion: The only parameter of Doppler velocimetry of the umbilical artery and vein which contributed to the detection of aneuploidies was the accidental discovery of the reverse blood flow in both vessels. Although our favorable results demonstrated that the Doppler velocimetry of the ductus venosus is effective in detecting aneuploidies, this conclusion, however, is preliminary and needs further investigation.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(5):291-298
DOI 10.1590/S0100-72032001000500004
Objective: to study the value of Doppler velocimetry of the ductus venosus and of the umbilical artery and vein, in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Patients and Methods: a total of 314 fetuses were studied consecutively. In 112 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 202 cases the postnatal phenotype was used as a basis for the result. In addition to the routine ultrasonographic examination, all the fetuses were submitted to measurement of the nuchal translucency thickness and to Doppler velocimetry of the umbilical artery and vein, particularly of the ductus venosus. For statistical analysis the Fisher exact test and the Mann-Whitney test were used. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, the ductus venosus blood flow during atrial contraction was absent (1 case) and reverse (22 cases), sensitivity was 92%. In the group of normal fetuses (289 cases), 6 evaluations demonstrated alterations in the Doppler of the ductus venosus (specificity of 97.6%, positive and negative predictive values of 76.7% and 93.3%, respectively); the false-positive rate was 2.4%. In reference to the umbilical vein and umbilical artery, there was no statistically significant difference between the abnormal and the normal group. Conclusion: The only parameter of Doppler velocimetry of the umbilical artery and vein which contributed to the detection of aneuploidies was the accidental discovery of the reverse blood flow in both vessels. Although our favorable results demonstrated that the Doppler velocimetry of the ductus venosus is effective in detecting aneuploidies, this conclusion, however, is preliminary and needs further investigation.
