Você pesquisou por y - Revista Brasileira de Ginecologia e Obstetrícia
You searched for:"Antonio Carlos Vieira Cabral"
We found (23) results for your search.Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(8):450-455
DOI 10.1590/S0100-72032005000800003
PURPOSE: to test a new, noninvasive method for the diagnosis of fetal anemia in red blood cell isoimmunized pregnancies. METHODS: the index obtained by the ratio between the ultrasonographic measurement of the biventricular outer dimension (BVOD) and femur length (both in centimeters) was correlated with fetal hemoglobin values in a cross-sectional study. Fifty-nine fetuses of isoimmunized pregnancies selected for invasive treatment and submitted to 130 cordocenteses for the diagnosis and treatment of anemia were included in the study. The cardiofemoral index was obtained immediately before the cordocentesis and the fetal hemoglobin index was obtained from fetal blood samples. Linear regression was carried out to assess the correlation between the index and fetal hemoglobin; ROC curve was applied to determine the most accurate cutoff for the diagnosis of the fetal hemoglobin concentration below 10g/dl. RESULTS: BVOD measurement varied from 1.6 to 4.7 cm (average 2.5±1.3cm), and length of the femur, from 3.0 to 6.9 cm (average 4.3±0.9 cm). The cardiofemoral index varied from 0.4 to 1.0 (average 0.6±0.1). A significant inverse correlation between the cardiofemoral index and fetal hemoglobin (R²=0.37 and p<0.0001) was observed. The cutoff of 0.60 was the best to predict a level of fetal hemoglobin below or equal to 10.0g/dl: 80.85% sensitivity, 83.13% specificity, 73.8% positive predictive value, and 88.46% negative predictive value, in the diagnosis of fetuses anemia. CONCLUSION: the cardiofemoral index allows for good accuracy in the prediction of fetal hemoglobin concentration below 10g/dl in red blood cell isoimmunized pregnancies. It may thus be applied as a noninvasive method to the diagnosis of this pathology.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(8):450-455
DOI 10.1590/S0100-72032005000800003
PURPOSE: to test a new, noninvasive method for the diagnosis of fetal anemia in red blood cell isoimmunized pregnancies. METHODS: the index obtained by the ratio between the ultrasonographic measurement of the biventricular outer dimension (BVOD) and femur length (both in centimeters) was correlated with fetal hemoglobin values in a cross-sectional study. Fifty-nine fetuses of isoimmunized pregnancies selected for invasive treatment and submitted to 130 cordocenteses for the diagnosis and treatment of anemia were included in the study. The cardiofemoral index was obtained immediately before the cordocentesis and the fetal hemoglobin index was obtained from fetal blood samples. Linear regression was carried out to assess the correlation between the index and fetal hemoglobin; ROC curve was applied to determine the most accurate cutoff for the diagnosis of the fetal hemoglobin concentration below 10g/dl. RESULTS: BVOD measurement varied from 1.6 to 4.7 cm (average 2.5±1.3cm), and length of the femur, from 3.0 to 6.9 cm (average 4.3±0.9 cm). The cardiofemoral index varied from 0.4 to 1.0 (average 0.6±0.1). A significant inverse correlation between the cardiofemoral index and fetal hemoglobin (R²=0.37 and p<0.0001) was observed. The cutoff of 0.60 was the best to predict a level of fetal hemoglobin below or equal to 10.0g/dl: 80.85% sensitivity, 83.13% specificity, 73.8% positive predictive value, and 88.46% negative predictive value, in the diagnosis of fetuses anemia. CONCLUSION: the cardiofemoral index allows for good accuracy in the prediction of fetal hemoglobin concentration below 10g/dl in red blood cell isoimmunized pregnancies. It may thus be applied as a noninvasive method to the diagnosis of this pathology.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(9):691-695
DOI 10.1590/S0100-72032004000900003
PURPOSE: to evaluate the importance of circulating maternal and fetal leptin in the healthy gestation, using its association with maternal, placental and fetal anthropometric variables, obtained at birth, and the relationship between the evaluated compartments. METHODS: in a transversal study a population of 33 single, healthy and term gestations was studied. The evaluated variables were maternal age, maternal weight, body mass index (BMF), weight of the newborn, placental weight, and placental index. Samples of maternal blood were immediately obtained before birth and from fetal umbilical cord blood at birth. Determination of serum leptin was performed using conventional radioimmunoassay. The relationships between serum leptin concentrations in maternal blood, umbilical artery and vein and the studied variables were assessed through linear regression. RESULTS: leptin levels were detected in the blood of all 33 pregnant women and their respective newborns, with maternal blood concentration (17.1±1.77 ng/mL) higher than that of umbilical vessels (vein: 9.0±1.16 ng/mL; artery: 8.23±1.02 ng/mL), p<0.0001. Leptin concentrations in the maternal blood were correlated with leptin concentrations in fetal blood (artery: coef. 0.63, p=0.037; vein: coef. 0.72, p=0.006). Regarding the anthropometric variables, leptin measured in the maternal blood was associated with initial and final maternal BMF (coef. 1.13; p=0.002; coef. 1,18, p=0.001) and cord leptin levels were correlated with the fetal weight at birth (vein: coef. 0.007, p=0.02; artery: coef. 0.006, p=0.02). CONCLUSION: there was a correlation between maternal and fetal leptin production and probably by the action of similar stimuli during gestation. Serum leptin was associated with the weight of the compartment where it circulates.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(9):691-695
DOI 10.1590/S0100-72032004000900003
PURPOSE: to evaluate the importance of circulating maternal and fetal leptin in the healthy gestation, using its association with maternal, placental and fetal anthropometric variables, obtained at birth, and the relationship between the evaluated compartments. METHODS: in a transversal study a population of 33 single, healthy and term gestations was studied. The evaluated variables were maternal age, maternal weight, body mass index (BMF), weight of the newborn, placental weight, and placental index. Samples of maternal blood were immediately obtained before birth and from fetal umbilical cord blood at birth. Determination of serum leptin was performed using conventional radioimmunoassay. The relationships between serum leptin concentrations in maternal blood, umbilical artery and vein and the studied variables were assessed through linear regression. RESULTS: leptin levels were detected in the blood of all 33 pregnant women and their respective newborns, with maternal blood concentration (17.1±1.77 ng/mL) higher than that of umbilical vessels (vein: 9.0±1.16 ng/mL; artery: 8.23±1.02 ng/mL), p<0.0001. Leptin concentrations in the maternal blood were correlated with leptin concentrations in fetal blood (artery: coef. 0.63, p=0.037; vein: coef. 0.72, p=0.006). Regarding the anthropometric variables, leptin measured in the maternal blood was associated with initial and final maternal BMF (coef. 1.13; p=0.002; coef. 1,18, p=0.001) and cord leptin levels were correlated with the fetal weight at birth (vein: coef. 0.007, p=0.02; artery: coef. 0.006, p=0.02). CONCLUSION: there was a correlation between maternal and fetal leptin production and probably by the action of similar stimuli during gestation. Serum leptin was associated with the weight of the compartment where it circulates.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(8):649-653
DOI 10.1590/S0100-72032004000800009
PURPOSE: to assess the correlation between middle cerebral artery peak systolic velocity and umbilical cord blood hemoglobin concentration and to determine its diagnostic value. PATIENTS AND METHODS: a cross-sectional prospective study was performed from January 2000 to May 2003. Forty-four isoimmunized pregnant women underwent a protocol for the identification of fetal hemolysis. When intrauterine transfusions were indicated, the umbilical cord blood hemoglobin concentration was measured at the beginning of the procedure. Each intrauterine transfusion preceded by Doppler velocimetry of the middle cerebral artery was regarded as one case, summing up eighty-three procedures. In all cases, the middle cerebral artery Doppler examinations were performed within the three hours preceding fetal blood sample collection. The systolic velocity peak was recorded and considered abnormal when its value was above 1.5 times the median for the corresponding gestational age. Hemocue® (B-Hemoglobin Photometer Hemocue AB; Angelholm, Sweden) was the device used to measure fetal hemoglobin concentration. The relationship between middle cerebral artery peak systolic velocity and cord blood hemoglobin was obtained by the chi2 test, considered significant at p<0.05. RESULTS: in thirty-three cases the cord blood hemoglobin concentration was below 10.0 g/dL. There was a strong correlation between the two measured variables (p<0.001). The middle cerebral artery peak systolic velocity with values above 1.5 times the median was associated with cord blood hemoglobin concentration below 10 g/mL (p<0,001). The sensitivity of an increased middle cerebral artery peak systolic velocity was 75.8% for the detection of a cord blood hemoglobin level of 10 g/dL or lower. CONCLUSION: the middle cerebral artery peak systolic velocity can be used as a noninvasive method for the diagnosis of fetal anemia.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(8):649-653
DOI 10.1590/S0100-72032004000800009
PURPOSE: to assess the correlation between middle cerebral artery peak systolic velocity and umbilical cord blood hemoglobin concentration and to determine its diagnostic value. PATIENTS AND METHODS: a cross-sectional prospective study was performed from January 2000 to May 2003. Forty-four isoimmunized pregnant women underwent a protocol for the identification of fetal hemolysis. When intrauterine transfusions were indicated, the umbilical cord blood hemoglobin concentration was measured at the beginning of the procedure. Each intrauterine transfusion preceded by Doppler velocimetry of the middle cerebral artery was regarded as one case, summing up eighty-three procedures. In all cases, the middle cerebral artery Doppler examinations were performed within the three hours preceding fetal blood sample collection. The systolic velocity peak was recorded and considered abnormal when its value was above 1.5 times the median for the corresponding gestational age. Hemocue® (B-Hemoglobin Photometer Hemocue AB; Angelholm, Sweden) was the device used to measure fetal hemoglobin concentration. The relationship between middle cerebral artery peak systolic velocity and cord blood hemoglobin was obtained by the chi2 test, considered significant at p<0.05. RESULTS: in thirty-three cases the cord blood hemoglobin concentration was below 10.0 g/dL. There was a strong correlation between the two measured variables (p<0.001). The middle cerebral artery peak systolic velocity with values above 1.5 times the median was associated with cord blood hemoglobin concentration below 10 g/mL (p<0,001). The sensitivity of an increased middle cerebral artery peak systolic velocity was 75.8% for the detection of a cord blood hemoglobin level of 10 g/dL or lower. CONCLUSION: the middle cerebral artery peak systolic velocity can be used as a noninvasive method for the diagnosis of 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. 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. 2000;22(6):365-371
DOI 10.1590/S0100-72032000000600007
Purpose: to evaluate the accuracy of prenatal ultrasound in the diagnosis of nephrouropathies. Methods: the authors followed-up 127 pregnancies referred to the Fetal Medicine Center of UFMG with suspicion of these anomalies. Fetal biometry, growth, vitality, and associated malformations were evaluated. Finally, a detailed description of the renal system was made to define the prenatal morphologic diagnosis of the malformations to be compared with the postnatal diagnosis. Results: based on the kappa index (statistical method that measures the concordance between different measurements, methods or measurement instruments: below 0.40, poor agreement; between 0.40 and 0.75, good agreement; above 0.75, excellent ageement), the authors found an excellent concordance (kappa index 0.95). Among the 127 cases, there were only 9 misdiagnoses, all of them of obstructive uropathies: 6 cases showed different obstruction levels after delivery and in three cases there were confounding diagnosis with multicystic kidney. Conclusions: the detailed ultrasonographic description of the renal system is a good method for prenatal diagnosis of the fetal nephropathies, allowing some options to modify the outcome of these fetuses, like to send them to specialized centers, to anticipate delivery and even to apply intrauterine therapy, in order to preserve the renal function. Serial echography and amnioinfusion can be used to improve the precision of prenatal diagnosis.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2000;22(6):365-371
DOI 10.1590/S0100-72032000000600007
Purpose: to evaluate the accuracy of prenatal ultrasound in the diagnosis of nephrouropathies. Methods: the authors followed-up 127 pregnancies referred to the Fetal Medicine Center of UFMG with suspicion of these anomalies. Fetal biometry, growth, vitality, and associated malformations were evaluated. Finally, a detailed description of the renal system was made to define the prenatal morphologic diagnosis of the malformations to be compared with the postnatal diagnosis. Results: based on the kappa index (statistical method that measures the concordance between different measurements, methods or measurement instruments: below 0.40, poor agreement; between 0.40 and 0.75, good agreement; above 0.75, excellent ageement), the authors found an excellent concordance (kappa index 0.95). Among the 127 cases, there were only 9 misdiagnoses, all of them of obstructive uropathies: 6 cases showed different obstruction levels after delivery and in three cases there were confounding diagnosis with multicystic kidney. Conclusions: the detailed ultrasonographic description of the renal system is a good method for prenatal diagnosis of the fetal nephropathies, allowing some options to modify the outcome of these fetuses, like to send them to specialized centers, to anticipate delivery and even to apply intrauterine therapy, in order to preserve the renal function. Serial echography and amnioinfusion can be used to improve the precision of prenatal diagnosis.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(6):413-418
DOI 10.1590/S0100-72032003000600005
PURPOSE: to determine the existence of association between blood pressure rise and plasma ANP and BNP levels in pregnancies complicated by preeclampsia, considering the existence of a hypertensive state before pregnancy and supportive drug influence on these hormones. METHODS: in a case-control transversal study, 86 pregnant women were assessed regarding arterial pressure level and plasma ANP and BNP levels. Clinical and laboratory tests were carried out to diagnose preeclampsia and the use of hypotensive drugs and magnesium sulfate was considered. Hormone determinations were obtained through radioimmunoassay, after extraction in C18 Sep-pak columns. Correlation was investigated by means and regression analysis in the whole group of pregnant women and in specific groups, considering prior hypertension. RESULTS: plasma ANP values were 41.5±7.3, 78.4±13.1 and 89.2±13.4pg/mL (p<0.00001) and plasma BNP values were 79.5±15.8, 176.7±42.2 and 208.3±63.5 pg/mL (p=0.005), respectively, for mean blood pressure =107 mmHg, 107-139 mmHg and =140 mmHg. It was verified that the positive correlation between plasma ANP concentrations and pressure levels in preeclampsia did not depend on the existence of a hypertensive state before pregnancy (p<0.0001: preeclampsia and p<0.01: preeclampsia superimposed on chronic hypertension), whereas BNP dosages were not associated with the arterial pressure in the group with arterial hypertension prior to pregnancy (p=0.004: preeclampsia and p=0.18: preeclampsia superimposed on chronic hypertension). CONCLUSION: aggravation of hypertension in preeclampsia correlates with serum ANP and BNP concentrations, although BNP values may be influenced by the existence of a prior hypertensive state.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(6):413-418
DOI 10.1590/S0100-72032003000600005
PURPOSE: to determine the existence of association between blood pressure rise and plasma ANP and BNP levels in pregnancies complicated by preeclampsia, considering the existence of a hypertensive state before pregnancy and supportive drug influence on these hormones. METHODS: in a case-control transversal study, 86 pregnant women were assessed regarding arterial pressure level and plasma ANP and BNP levels. Clinical and laboratory tests were carried out to diagnose preeclampsia and the use of hypotensive drugs and magnesium sulfate was considered. Hormone determinations were obtained through radioimmunoassay, after extraction in C18 Sep-pak columns. Correlation was investigated by means and regression analysis in the whole group of pregnant women and in specific groups, considering prior hypertension. RESULTS: plasma ANP values were 41.5±7.3, 78.4±13.1 and 89.2±13.4pg/mL (p<0.00001) and plasma BNP values were 79.5±15.8, 176.7±42.2 and 208.3±63.5 pg/mL (p=0.005), respectively, for mean blood pressure =107 mmHg, 107-139 mmHg and =140 mmHg. It was verified that the positive correlation between plasma ANP concentrations and pressure levels in preeclampsia did not depend on the existence of a hypertensive state before pregnancy (p<0.0001: preeclampsia and p<0.01: preeclampsia superimposed on chronic hypertension), whereas BNP dosages were not associated with the arterial pressure in the group with arterial hypertension prior to pregnancy (p=0.004: preeclampsia and p=0.18: preeclampsia superimposed on chronic hypertension). CONCLUSION: aggravation of hypertension in preeclampsia correlates with serum ANP and BNP concentrations, although BNP values may be influenced by the existence of a prior hypertensive state.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(5):323-328
DOI 10.1590/S0100-72032003000500004
PURPOSE: to determine whether an elective cesarean section at the 38th week of gestation for HIV positive patients, in spite of decreasing vertical transmission, increases the risk of maternal death. METHODS: fifty-eight HIV-infected patients were studied and submitted to the complete ACTG 076 protocol (oral administration of zidovudine in the prenatal period associated with the intravenous form at delivery) followed by an elective cesarean section at the 38th week of gestation. The control group consisted of 226 noninfected women (the first four patients submitted to an elective cesarian section after each cesarian section in infected patient). The analyzed variables were: uterine atonia, puerperal fever, abdominal wall infection, urinary infection, endometritis, average blood loss, surgery time, and hospitalization time. Data were analyzed by the c² test (the Fisher test was used when there were less than 5 cases). The relative risk was calculated with the Epi-Info 6.0 program. RESULTS: results show that the elective cesarean section performed on HIV-positive patients, when compared to the control group, did not present a higher incidence of uterine atonia, puerperal fever, abdominal wall infection, urinary infection or endometritis. However, a greater average blood loss (2.26 relative risk) was recorded as well as an extended surgery time (3.32 relative risk). The HIV-infected patients remained less time in hospital than the noninfected control group (0.33 relative risk). CONCLUSION: we conclude that there was no increase in maternal morbidity after cesarean section as a means of interrupting gestation in the HIV-infected patients.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(5):323-328
DOI 10.1590/S0100-72032003000500004
PURPOSE: to determine whether an elective cesarean section at the 38th week of gestation for HIV positive patients, in spite of decreasing vertical transmission, increases the risk of maternal death. METHODS: fifty-eight HIV-infected patients were studied and submitted to the complete ACTG 076 protocol (oral administration of zidovudine in the prenatal period associated with the intravenous form at delivery) followed by an elective cesarean section at the 38th week of gestation. The control group consisted of 226 noninfected women (the first four patients submitted to an elective cesarian section after each cesarian section in infected patient). The analyzed variables were: uterine atonia, puerperal fever, abdominal wall infection, urinary infection, endometritis, average blood loss, surgery time, and hospitalization time. Data were analyzed by the c² test (the Fisher test was used when there were less than 5 cases). The relative risk was calculated with the Epi-Info 6.0 program. RESULTS: results show that the elective cesarean section performed on HIV-positive patients, when compared to the control group, did not present a higher incidence of uterine atonia, puerperal fever, abdominal wall infection, urinary infection or endometritis. However, a greater average blood loss (2.26 relative risk) was recorded as well as an extended surgery time (3.32 relative risk). The HIV-infected patients remained less time in hospital than the noninfected control group (0.33 relative risk). CONCLUSION: we conclude that there was no increase in maternal morbidity after cesarean section as a means of interrupting gestation in the HIV-infected patients.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(4):261-268
DOI 10.1590/S0100-72032003000400007
PURPOSE: to evaluate Doppler velocimetry of the ductus venosus as a noninvasive test of abnormal pH and gas analysis in preterm fetuses with "brain sparing reflex". METHODS: a cross-sectional study was performed. The studied population consisted of 48 pregnant women between the 25th and the 33rd week of gestation, whose fetuses presented brain sparing reflex (umbilical/cerebral ratio >1). The time elapsed between Doppler velocimetry and the birth (cesarean section under peridural anesthesia) was of up to 5 h. The following parameters were studied: S/A ratio of the ductus venosus, pH and base excess (BE) of fetal blood sample (collected from the umbilical vein immediately after birth). The S/A ratio of the ductus venosus was considered abnormal when superior to 3.6. The fetuses were classified according to the gas analysis result. They were considered abnormal when pH <7.26 and BE £ 6 mMol/L. Fisher's test was used for statistical analysis and considered significant when p £ 0.05. RESULTS: there was a significant correlation between umbilical blood gas analysis in preterm fetuses with brain sparing reflex and ductus venosus S/A ratio (p = 0.0000082; Fisher test). Ductus venosus Doppler velocimetry identified 10 of 14 fetuses with abnormal gas analysis. On the other hand, 32 of 34 fetuses with normal gas analysis were correctly identified. The sensitivity of the ductus venosus S/A ratio for the diagnosis of abnormal blood gas analysis was 71%, specificity 94%, false-negative rate 8%, false-positive rate 4%, positive predictive value 83% and negative predictive value 89%. Pretest likelihood, post-test posterior probability following a positive test result (post-test likelihood) and post-test posterior probability following a negative test result (post-test likelihood) were 31, 84 and 10%, respectively. CONCLUSION: the analysis of the ductus venosus S/A ratio is adequate for the diagnosis of abnormal blood gas analysis in preterm fetuses presenting brain sparing reflex.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(4):261-268
DOI 10.1590/S0100-72032003000400007
PURPOSE: to evaluate Doppler velocimetry of the ductus venosus as a noninvasive test of abnormal pH and gas analysis in preterm fetuses with "brain sparing reflex". METHODS: a cross-sectional study was performed. The studied population consisted of 48 pregnant women between the 25th and the 33rd week of gestation, whose fetuses presented brain sparing reflex (umbilical/cerebral ratio >1). The time elapsed between Doppler velocimetry and the birth (cesarean section under peridural anesthesia) was of up to 5 h. The following parameters were studied: S/A ratio of the ductus venosus, pH and base excess (BE) of fetal blood sample (collected from the umbilical vein immediately after birth). The S/A ratio of the ductus venosus was considered abnormal when superior to 3.6. The fetuses were classified according to the gas analysis result. They were considered abnormal when pH <7.26 and BE £ 6 mMol/L. Fisher's test was used for statistical analysis and considered significant when p £ 0.05. RESULTS: there was a significant correlation between umbilical blood gas analysis in preterm fetuses with brain sparing reflex and ductus venosus S/A ratio (p = 0.0000082; Fisher test). Ductus venosus Doppler velocimetry identified 10 of 14 fetuses with abnormal gas analysis. On the other hand, 32 of 34 fetuses with normal gas analysis were correctly identified. The sensitivity of the ductus venosus S/A ratio for the diagnosis of abnormal blood gas analysis was 71%, specificity 94%, false-negative rate 8%, false-positive rate 4%, positive predictive value 83% and negative predictive value 89%. Pretest likelihood, post-test posterior probability following a positive test result (post-test likelihood) and post-test posterior probability following a negative test result (post-test likelihood) were 31, 84 and 10%, respectively. CONCLUSION: the analysis of the ductus venosus S/A ratio is adequate for the diagnosis of abnormal blood gas analysis in preterm fetuses presenting brain sparing reflex.
