You searched for:"Renato Martins Santana"
We found (4) results for your search.Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(1):5-11
DOI 10.1590/S0100-72032008000100002
PURPOSE: to study the value of Doppler velocimetry of the ductus venosus, between the 11th and 14th weeks of pregnancy, associated to the nuchal translucency thickness measurement, in the detection of adverse fetal outcome. METHODS: a transversal and prospective study in which a total of 1,268 fetuses were studied consecutively. In 56 cases, a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus and, in 1,181 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 ductus venosus. Aiming at prevalence and accuracy indices, sensitivity, specificity, positive predictive value, negative predictive value, probability of false-positive, probability of false-negative, reason of positive probability and reason of negative probability were calculated and analyzed. RESULTS: from the total of 1,268 fetuses, 1,183 cases were selected for analysis. From this number, 1,170 fetuses were normal (98.9%) and 13 fetuses presented adverse outcome at birth (1.1%), including fetal death (trisomy 21 and 22) in two cases; genetic syndrome (Nooman) in one case; two cases of polymalformed fetuses; cardiopathy in three cases; and other structural defects in five cases. The prevalence of the modified ductus venosus (wave A zero/reverse) in the studied population was of 14 cases (1.2%), with a false-positive rate of 0.7%. CONCLUSIONS: there is a significant correlation between the alteration of the ductus venosus Doppler velocimetry and the thickness of the nuchal translucency as an ultrasonographic marker for the first trimester of gestation, in the detection of adverse fetal outcome, especially serious malformations. The ductus venosus was able to diminish the false-positive result in comparison to the isolated use of the nuchal translucency thickness, improving considerably the positive predictive value of the test.
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. 2003;25(6):425-430
DOI 10.1590/S0100-72032003000600007
PURPOSE: to determine whether prenatal sonographic findings and uterine contractions can predict neonatal motor outcome in fetuses with open spina bifida. METHODS: we evaluated retrospectively 53 fetuses with open spina bifida from 1993 to 2001. These fetuses were born and followed-up at the fetal medicine units of the Hospital São Paulo ("Universidade Federal de São Paulo") and the "Hospital Santa Joana". The influence of the alterations observed through ultrasound scan on neonatal muscular strength (macrocrania, microcrania, level of the spinal column opening, clubfoot and type of fetus position) was evaluated. The influence of uterine contractions on neonatal motor outcome was also evaluated. All deliveries were made through cesarian section. c² and Fisher tests were used for categorical comparisons. A p<0.05 was considered significant. RESULTS: Fifty-three cases of isolated open spina bifida were studied. Alterations of the cranial circumference size and the level of the lesion did not interfere in the neonatal motor perfomance. However, clubfoot and breech position showed to be predictors of an unfavorable neurological prognosis (p<0.05). Twenty-tree (43%) infants had clubfoot. Eighteen (78.3%) of these had abnormal leg movements. No infant in breech presentation (n=10) showed normal motor function. The presence of uterine contractions and the premature membrane rupture, observed in 13 fetuses (87%), were also linked to the alteration of neonatal muscular strength (p<0.05). CONCLUSION: clubfoot and breech presentation are ultrasonographic findings useful in predicting neurological neonatal outcome. Uterine contractions and premature membrane rupture are associated with poor motor neonatal outcome.