Placental circulation Archives - Revista Brasileira de Ginecologia e Obstetrícia

  • Original Articles

    Reference range of uterine artery Doppler parameters between the 11th and 14th pregnancy weeks in a population sample from Northeast Brazil

    Revista Brasileira de Ginecologia e Obstetrícia. 2013;35(8):357-362

    Summary

    Original Articles

    Reference range of uterine artery Doppler parameters between the 11th and 14th pregnancy weeks in a population sample from Northeast Brazil

    Revista Brasileira de Ginecologia e Obstetrícia. 2013;35(8):357-362

    DOI 10.1590/S0100-72032013000800004

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    PURPOSE: To establish reference values for the first trimester uterine artery resistance index (UtA-RI) and pulsatility index (UtA-PI) in healthy singleton pregnant women from Northeast Brazil. METHODS: A prospective observational cohort study including 409 consecutive singleton pregnancies undergoing routine early ultrasound screening at 11 - 14 weeks of gestation was performed. The patients responded to a questionnaire to assess maternal epidemiological characteristics. The left and right UtA-PI and UtA-RI were examined by color and pulsed Doppler by transabdominal technique and the mean UtA-PI, mean UtA-RI and the presence of bilateral protodiastolic notching were recorded. Quartile regression was used to estimate reference values. RESULTS: The mean±standard deviation UtA-RI and UtA-PI were 0.7±0.1 and 1.5±0.5, respectively. When segregated for gestation age, mean UtA-PI was 1.6±0.5 at 11 weeks, 1.5±0.6 at 12 weeks, 1.4±0.4 at 13 weeks and 1.3±0.4 at 14 weeks' gestation and mean UtA-RI was 0.7±0.1 at 11 weeks, 0.7±0.1 at 12 weeks, 0.6±0.1 at 13 weeks and 0.6±0.1 at 14 weeks' gestation. Uterine artery bilateral notch was present in 261 (63.8%) patients. We observed that the 5th and 95th percentiles of the UtA-PI and UtA-RI uterine arteries were 0.7 and 2.3 and, 0.5 and 0.8, respectively. CONCLUSION: Normal reference range of uterine artery Doppler in healthy singleton pregnancies from Northeast Brazil was established. The 95th percentile of UtA-PI and UtA-RI values may serve as a cut-off for future prediction of pregnancy complications studies (i.e., pre-eclampsia) in Northeast Brazil.

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  • Artigos Originais

    Maternal complications following endoscopic surgeries in fetal Medicine

    Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(6):260-266

    Summary

    Artigos Originais

    Maternal complications following endoscopic surgeries in fetal Medicine

    Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(6):260-266

    DOI 10.1590/S0100-72032010000600002

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    PURPOSE: to describe the maternal complications due to therapeutic endoscopic procedures in fetal Medicine performed at an university center in Brazil. METHODS: retrospective observational study including patients treated from April 2007 to May 2010 who underwent laser ablation of placental vessels (LAPV) for severe twin-twin transfusion syndrome (TTTS); fetal tracheal occlusion (FETO) and endoscopic removal of tracheal balloon in cases of severe congenital diaphragmatic hernia (CDH); LAPV with or without bipolar coagulation of the umbilical cord in cases of twin reversed arterial perfusion (TRAP) sequence. The main variables described for each disease/type of surgery were maternal complications and neonatal survival (discharge from nursery). RESULTS: fifty-six patients underwent 70 procedures: Severe TTTS (34 patients; 34 surgeries); severe CDH (16 patients; 30 surgeries), and TRAP sequence (6 patients; 6 surgeries). Among 34 women who underwent LAPV for TTTS, two (2/34=5.9%) experienced amniotic fluid leakage to the peritoneal cavity and seven (7/34=20.6%) miscarried after the procedure. Survival of at least one twin was 64.7% (22/34). Among 30 interventions performed in cases of CDH, there was amniotic fluid leakage into the maternal peritoneal cavity in one patient (1/30=3.3%) and premature preterm rupture of membranes after three (3/30=30%) fetoscopies for removal of the tracheal balloon. Infant survival with discharge from nursery was 43.8% (7/16). Among six cases of TRAP sequence, there was bleeding into the peritoneal cavity after surgery in one patient (1/6=16.7%) and neonatal survival with discharge from nursery was 50% (3/6). CONCLUSIONS: in agreement with the available data in literature, at our center, the benefits related to therapeutic endoscopic interventions for TTTS, CDH and TRAP sequence seem to overcome the risks of maternal complications, which were rarely considered severe.

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  • Artigo de Revisão

    Brain sparing effect: from placental insufficiency to fetal circulatory adaptation

    Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(7):366-371

    Summary

    Artigo de Revisão

    Brain sparing effect: from placental insufficiency to fetal circulatory adaptation

    Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(7):366-371

    DOI 10.1590/S0100-72032008000700008

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    The application and development of obstetric Dopplervelocimetry provide a basis for the investigation of placental insufficiency and demonstrate the dynamic behavior of fetal circulation during hypoxia. In clinical practice, assessing hemodynamics in three vascular regions involved in pregnancy, namely the uterine, umbilical and middle cerebral arteries, has become routine. Roughly, the cerebral artery expresses the balance between uterine artery oxygen supply and umbilical artery oxygen uptake. Currently, when such balance is unfavorable, the fetal cardiac reserve is investigated by assessing the venous duct. However, determining and interpreting vascular resistance indexes is not an easy task. The starting point is to know the physiopathology of placental insufficiency and fetal circulatory adaptation through which Doppler confirmed its role in the assessment of fetal well-being.

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    Brain sparing effect: from placental insufficiency to fetal circulatory adaptation
  • Artigos Originais

    Brain-sparing effect: comparison of diagnostic indices

    Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(1):11-18

    Summary

    Artigos Originais

    Brain-sparing effect: comparison of diagnostic indices

    Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(1):11-18

    DOI 10.1590/S0100-72032010000100003

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    PURPOSE: to describe adverse perinatal outcomes in patients with fetal blood flow centralization, using the relationship between the pulsatility indexes of the middle cerebral and umbilical arteries (MCAPI/UAPI), and between the resistance indexes of the middle cerebral and umbilical arteries (MCARI/UARI), as well as to compare both diagnostic indexes. METHODS: 151 pregnant women with diagnosis of blood flow centralization, attended to at the maternity hospital of Universidade Estadual de Campinas, whose delivery occurred up to 15 days after the ultrasonographic diagnosis, were included. It was considered as adverse perinatal outcomes: Apgar index lower than 7 at the fifth minute, permanence in neonatal ICU, small fetus for the gestational age, severe fetal suffering, perinatal death, hypoglycemia, polycythemia, necrotizing enterocolitis, brain hemorrhage, lung hemorrhage, anemia, septicemia, hyaline membrane disease, convulsive syndromes, hyperreflexia syndrome and kidney insufficiency. Rates of the perinatal adverse outcomes (PAO) for the brain-placentary ratios have been compared, using Fisher's exact or Pearson's χ2 tests, at 5% significance level. Adverse perinatal outcomes according to the gestational age have been evaluated using the Cochrane-Armitage test for trend. RESULTS: the adverse perinatal outcomes for the group with the two indexes altered were: 62.5% of the newborns needed to be placed in an ICU, 75.2% were small for the gestational age (SGA), 35.3% were under severe fetal suffering, 84.4% had hypoglycemia, 8.3% polycythemia, 4.2% necrotizing enterocolitis, and 2.1% brain hemorrhage. There has been significant association between the MCAPI/UAPI and MCARI/UARI ratios along the gestational age, and the need for neonatal intensive care, small fetuses for the gestational age, septicemia, necrotizing enterocolitis, kidney insufficiency, hyaline membrane disease, and anemia. There has been no significant difference between the two indexes of adverse perinatal outcome.

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  • Artigos Originais

    Materno-fetal hemodynamic repercussion of glucose ingestion

    Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(12):693-699

    Summary

    Artigos Originais

    Materno-fetal hemodynamic repercussion of glucose ingestion

    Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(12):693-699

    DOI 10.1590/S0100-72032006001200002

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    PURPOSE: to analyze the effect of glucose in the materno-fetal hemodynamics through dopplervelocimetric assessment of the materno-fetal and fetoplacentary circulation. METHODS: the study was carried out by a single observer on 31 clinically healthy pregnant women from the 28th to the 36th gestational week. Parameters were assessed immediately before or 60 minutes after the ingestion of 50 g of glucose. The including criteria comprised normal clinical and laboratorial evaluation, the presence of only one fetus, gestational age between 28 and 36 weeks confirmed by ultrasonography and/or the date of the last menstruation, fasting glycemia less or equal to 110 mg/dL and less than 140 mg/dL after 50 g of glucose overload. The excluding criteria consisted of the presence of fetal malformation or development alterations, labor, diabetes as a family predisposition, pathologies due to or underlying gestation and use of tobacco, alcohol and/or other substances. The mother´s common carotid artery and uterine arteries, the umbilical artery and the fetal medial cerebral artery and abdominal aorta were evaluated. In each blood vessel, the following parameters were analyzed: resistance index, pulsatility index, maximum systolic speed, final diastolic speed and acceleration time. The fetal heart rate was evaluated by M Mode ultrasonography. For the statistical analysis, the Student's t test was used when the variable presented normal distribution in Kolmogorov-Smirnov's test. When normality was rejected, the Wilcoxon's non-parametric test was used, with the significance level always established at p<0.05. RESULTS: the maternal glycemia increased after the ingestion of 50 g of glucose (before: 68.0±10.1 mg/dL and after: 104.6±28.2 mg/dL; p<0.001), and fetal heart rate decreased after the glucose ingestion (before: 137.9±6.1 bpm and after: 134.5±6.9 bpm; p<0.001). The umbilical artery presented an increase in the pulsatility index (before: 0.8±0.1 and after: 0.9±0.2; p=0.03). Significant velocimetric alterations were not found in the other vessels or in the other indexes investigated. CONCLUSIONS: in spite of the variation in the levels of maternal glycemia and in the fetal heart rate following glucose ingestion, no significant flow alteration occurred in the following vessels: umbilical artery, fetal medial cerebral artery and aorta; nor in the carotid and uterine maternal arteries. We conclude that the glucose concentration used was released without hemodynamic interference in the materno-fetal compartment.

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  • Artigos Originais

    Effects of maternal smoking on placental ultrasound and uterine-placental Doppler

    Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(6):340-344

    Summary

    Artigos Originais

    Effects of maternal smoking on placental ultrasound and uterine-placental Doppler

    Revista Brasileira de Ginecologia e Obstetrícia. 2006;28(6):340-344

    DOI 10.1590/S0100-72032006000600004

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    PURPOSE: the study the effects of maternal cigarette smoking during pregnancy on placental maturation (calcifications) and the placental-uterine circulation, evaluated through umbilical and uterine Doppler. METHODS: prospective cohort study involving 244 pregnant women, 210 of them non-smokers and 34 smokers. Participants were submitted to four serial sonograms. The first was performed up to the 16th week of pregnancy to determine gestational age, and the other three at 28, 32 and 36 weeks for fetal biometry, evaluation of placental texture and Doppler studies of the uterine and umbilical arteries. Premature placental calcification was defined as grade III before 36 weeks. The chi2 and Fisher exact tests were used to compare placental grading, and the Mann-Whitney test to evaluate the resistance index of uterine and umbilical arteries. RESULTS: the frequency of grade III placenta and the resistance of the uterine arteries did not differ significantly between smokers and non-smokers, at all gestational ages. Umbilical artery Doppler was significantly higher in smokers than in non-smokers at 32 weeks. CONCLUSIONS: no association was found between cigarette smoking and premature placental calcification. Smoking was associated with increased umbilical artery resistance at 32 weeks.

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  • Trabalhos Originais

    Ductus venosus velocimetry: noninvasive identification of fetal acidemia in preterm fetuses with brain sparing reflex

    Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(5):355-361

    Summary

    Trabalhos Originais

    Ductus venosus velocimetry: noninvasive identification of fetal acidemia in preterm fetuses with brain sparing reflex

    Revista Brasileira de Ginecologia e Obstetrícia. 2004;26(5):355-361

    DOI 10.1590/S0100-72032004000500003

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    OBJECTIVE: to assess through Dopllerfluxometry the S/A ratio of the ductus venosus and determine the cut-off point to identify preterm fetuses with the 'brain sparing phenomenon". METHOD: a cross-sectional study was performed in 60 pregnant women that presented the "brain sparing phenomenon" (umbilical cerebral ratio >1) and gestational age between 25 and 33 weeks. The following parameters were studied: S/A ratio of the ductus venosus, pH and base excess (BE) of a fetal blood sample collected from the umbilical vein immediately after birth. The fetuses were classified according to the gas analysis result. They were considered abnormal when pH <7.20 and BE < -6 mmol/l. A receiver operator characteristic (ROC) curve analysis was performed to examine the relationship between S/A ratio and fetal acidemia. RESULTS: sixty pregnant women in the period of January 1998 to January 2003 were selected. In the moment of the study the gestational age varied from 25 to 33 weeks, with an average of 29.7 weeks (±1.8 weeks). All of the fetuses presented the "brain sparing phenomenon". Among them 14 presented abnormal gas analysis at birth and 46 presented normal gas analysis. The prevalence of fetuses with abnormal gas analysis in the studied material was 23.33%. Significant association was observed between the abnormal ductus venosus velocimetry and abnormal gas analysis at birth (chi2 = 784.44, p < 0.00001) in preterm fetuses with "brain sparing phenomenon". The best cut-off point of the S/A ratio (where the ROC curves bent) was 3.4. CONCLUSION: fetal acidemia in preterm fetuses with "brain sparing phenomenon" may be noninvasively identified by Doppler measurement of the ductus venosus when the S/A rises above 3.4.

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    Ductus venosus velocimetry: noninvasive identification of fetal acidemia in preterm fetuses with brain sparing reflex
  • Trabalhos Originais

    The placental bed in abruptio placentae

    Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(8):585-591

    Summary

    Trabalhos Originais

    The placental bed in abruptio placentae

    Revista Brasileira de Ginecologia e Obstetrícia. 2003;25(8):585-591

    DOI 10.1590/S0100-72032003000800007

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    PURPOSE: to analyze the histopathological patterns of the placental bed arteries in pregnancies complicated by abruptio placentae (AP) and compare them with the normal vascular histology of the placental bed. METHODS: placental bed biopsy was performed in 23 pregnant women with a diagnosis of abruptio placentae associated with high blood pressure (G/HBP) disorders, with gestational age of 28 weeks or more, submitted to cesarean section. The control group (CG) consisted of 30 patients without disease, submitted to cesarean section for obstetric reasons. The selected histological variables were: unaltered pattern, physiological changes, medial layer disorganization, hyperplastic changes, acute necrosis and atherosis. RESULTS: in patients with AP associated with HBP there was a significant predominance of medial layer disorganization and hyperplastic changes, compared to CG, while physiological changes in spiral arteries were statistically more common in CG. Findings of acute necrosis and atherosis were observed in a low number of G/HBP, with no statistical significance. CONCLUSIONS: in pregnant women with AP associated with HBP the predominant vascular histological findings were medial layer disorganization and hyperplastic changes. The presence of histopathological features was significantly higher in G/HBP, with prevalence of medial layer disorganization. Normal histological pattern, i.e., physiological changes, were more prevalent in CG.

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    The placental bed in abruptio placentae

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