Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Introduction: An assessment of the role of Doppler ultrasound velocity waveform analysis of the fetal umbilical arteries in the diagnosis of fetal distress in labour is made from a review of the literature and clinical study. Study objectives: 1) To determine the value of screening with Doppler ultrasound in high-risk labours in the prediction of the development of indicators of fetal distress. 2) To determine whether Doppler velocimetry indices of the umbilical arteries change with the development of indicators of fetal distress in labour. Design: Repeated Doppler velocimetry in selected high risk labours. Setting: Groote Schuur Hospital, Cape Town, South Africa, a large tertiary referral centre. Subjects: Thirty six women with singleton pregnancies complicated either by gestational proteinuric hypertension or by intrauterine growth retardation or both with a normal cardiotocographic tracing at the onset of labour. Main outcome measures: 1) Acid-base status of the fetus was assessed after deli very by analysis of umbilical artery blood. 2) Apgar score was recorded at 1 and 5 minutes. 3) Neonates were carefully examined for clinical signs of perinatal hypoxia. Results: Twenty seven fetuses were followed through labour. No relation was found between umbilical artery Pourcelot ratio (resistance index) on admission in labour and umbilical artery base deficit. Six fetuses were born with an umbilical artery base deficit of more than 10 mmol 1-1. Zero change in mean Pourcelot ratio was noted in both normal and acidotic fetuses. None of the acidotic fetuses showed a change in Pourcelot ratio of more than 0.03. The study had an 80% power to detect a change in mean Pourcelot ratio of 0.07 in the normal fetuses and 0.16 in the acidotic fetuses at a 95% confidence level. No relation was found between Pourcelot ratio on admission in labour or change in Pourcelot ratio during labour and Apgar score. None of the neonates showed clinical signs of perinatal hypoxia. Conclusions: Doppler velocimetry of the umbilical arteries in labour as measured by the Pourcelot ratio does not contribute to the diagnosis of fetal distress in labour.

The following thesis will describe the investigation of the effect of nifedipine (a calcium antagonist) on the Doppler flow velocity waveform of the umbilical artery. The thesis is divided into two parts. The first section is a literature review of the three main aspects of the thesis namely: 1. The uteroplacental circulation in humans and the pathophysiology related to this circulation in hypertension and intrauterine growth retardation (IUGR). 2. The biokinetics of nifedipine and a review of the experiments that have been performed using the drug in human and animal models. 3. The principles of Doppler ultrasound and the literature pertaining to its use in the study of the uteroplacental circulation. The second part of the thesis is devoted to the effect of nifedipine on fetal umbilical artery Doppler waveform analysis. In the first ·stage of the investigation the effect of the drug on hypertensive mothers has been examined, and in the second stage the effect on fetuses that have an increased resistance index of the umbilical artery Doppler waveform.

Umbilical flow velocity waveforms (FVW' s) can be measured non-invasively using Doppler ultrasound. Changes in the FVW's occur long before the warning signs from other conventional monitoring methods. Correct interpretation of the changes in the FVW has the potential of providing the clinician with an early warning of foetal distress. A number of indices have been described in the literature to characterise the FVW including the Pulsatility Index (PI), the Resistance Index (RI) and more recently, the High Resistance State Index (HRSI). Researchers have shown a dependence of the FVW, and thus the indices which describe it, on factors such as the placental resistance (Muijsers et al 1990a) blood pressure pulsatility (Mulders et al 1986), and the foetal heart rate (Downing et al 1991). In order to model the foetal circulation, the dimensions of the foetal vessels were required. These were taken from the literature when available, but had to be supplemented by measurements on post mortem specimens. This information, together with blood pressures and flow rates taken from the literature, was used to design electrical analogous models of the foetal arterial circulation (model 1 and model 2), which were implemented using PSpice, which is an electronic circuit simulator package. The Flow Velocity Waveforms (FVW's) simulated were stored and then analyzed using MATLAB, which is a mathematical package to calculate the waveform indices and both the blood pressure and percentage blood flow to the different anatomical regions of the foetus. Model 1 is a simple model of the umbilical placental unit only, which assumes a rectified sine wave with a D.C. offset as an input waveform while Model 2 is a distributed element model of the complete foetal arterial system, including a realistic representation of the foetal heart. AIM: Simulations of the FVW were used to examine the effects of placental obliteration (raised placental resistance), placental size, foetal heart rate (FHR), blood pressure pulsatility (BPPI), mean blood pressure (BP), and site of measurement of the FVW along the umbilical artery and thus on the waveform indices which are used to describe it (RI, PI and HRSI). RESULTS/ DISCUSSION: The investigations using models 1 and 2 showed that the indices were significantly dependent on the placental resistance, the size of the placenta and the type of placental obliteration. Model 1 was also used to investigate the effect of FHR variations on the indices under the original assumption that the input waveform to the umbilical/placental unit was a rectified sinusoid offset by a constant voltage (D.C.) (Thompson and Trudinger 1990). The result obtained, that is, the FHR does not affect the indices (in particular the PI) needed further investigation because the assumption for the input waveform is not true under all conditions. For this reason, the simulations were repeated using model 2, with the interesting result that there is a difference between short term FHR variations and long-term FHR variation. Short term FHR variations had a pronounced effect on the indices. The blood pressure pulsatility and the indices concerned varied by large amounts in this case, which indicated a link between the blood pressure pulsatility and all the indices. Long term FHR variations had an inconsistent but small effect on the blood pressure pulsatility and in turn had a small effect on the RI and PI. The mean blood pressure in these simulations decreased with increasing FHR which resulted in a pronounced increase in the HRSI which indicated the dependency of this index on the mean blood pressure rather than on the blood pressure pulsatility. It was found that the HRSI is a good index of placental resistance and may be particularly useful in evaluating high placental resistance in cases of absent flow during diastole, since, in these cases it is only slightly affected by the FHR. A value of greater than 34 percent is the recommended HRSI value to indicate severe foetal distress. The results also indicate that the FVW shape varies along the umbilical artery and is far more pulsatile at the aortic (proximal) end than the placental end. This is reflected in the indices which thus have worst case values at the placental end. It is thus recommended that, where possible, the indices are measured at the placental end of the umbilical artery.

No setor de Vitalidade Fetal na Clínica Obstétrica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo foi conduzido estudo caso-controle com seguimento prospectivo com quarenta e seis pacientes. O objetivo desse estudo foi identificar a associação dos testes de avaliação de vitalidade fetal e acidemia ao nascimento em gestações acometidas com dopplervelocimetria anormal e fluxo diastólico positivo das artérias umbilicais. Da mesma maneira, objetivou-se avaliar a relação entre os resultados antenatais, do parto, e neonatais com a ocorrência de pH fetal inferior a 7,20. A evolução para fluxo diastólico ausente ou reverso durante o seguimento foi critério de exclusão. Os casos foram classificados em dois grupos de acordo com a presença (grupo 1), ou ausência (grupo 2) de acidemia ao nascimento (pH inferior a 7,20), por meio da gasometria arterial de cordão imediatamente após o parto. As seguintes variáveis foram submetidas à análise univariada, comparando-se os grupos 1 e 2: idade materna, síndrome hipertensiva, uso de corticóde antenatal para maturação pulmonar, idade gestacional no momento do parto e testes de avaliação de vitalidade fetal do dia do parto. As modalidades dopplervelocimétricas analisadas foram: índice de pulsatilidade do território arterial (representado pela artéria umbilical e artéria cerebral média) e venoso (índice de pulsatilidade para veias do ducto venoso). Os seguintes parâmetros das atividades biofísicas fetais foram estudados: cardiotocografia (normal e anormal), presença de desaceleração tardia, presença de desaceleração (desaceleração tardia, ou desaceleração variável de mau prognóstico, ou desaceleração prolongada), ausência ou não de movimentos respiratórios, presença ou não de oligoâmnio e classificação do escore do perfil biofísico fetal (normal quando maior que 6, e anormal quando menor ou igual a 6). As variáveis clinicamente relevantes e estatisticamente significativas foram analisadas pela regressão logística. A série compôs-se de 46 pacientes classificadas nos grupos 1 (24 casos) e 2 (22 casos) e as seguintes variáveis foram estatisticamente relacionadas à ocorrência de acidemia no nascimento (p0,05): idade materna, síndrome hipertensiva, cardiotocografia anormal, presença de desaceleração, e ausência de movimentos respiratórios. Na regressão logística, a presença de desaceleração foi preditora de acidemia (p=0,024; OR=8,2; IC95%=1,2-52). Os presentes achados sustentam que a presença de acidemia ao nascimento em fetos com dopplevelocimetria anormal e fluxo diastólico positivo das AU está associada principalmente à anormalidade nos parâmetros agudos da avaliação da vitalidade fetal. A presença de desaceleração no traçado cardiotocográfico foi preditora de acidemia ao nascimento. / A longitudinal prospective study was conducted on 46 pregnancies with umbilical artery abnormal pulsatility index and positive diastolic flow velocity. Patients were evaluated at the Fetal Surveillance Unit/ Obstetrics Clinics of the University of São Paulo Medical School General Hospital (HCFMUSP) between February 2007 and March 2009. The objective of this study was to identify a potential association between fetal antenatal surveillance tests and acidemia at birth, in pregnancies with umbilical artery abnormal Doppler velocimetry and positive diastolic flow. In the same context, this research aimed to establish the correlation of data of birth, and neonatal outcome with umbilical cord pH below 7,20. The development of reversed or absent end- diastolic flow velovity in the umbilical artery was an excluision criteria. The cases were divided in two groups, according to the presence (Group 1) or absence (Group 2) of acidemia at birth (pH below 7.20), based on umbilical cord blood gas measurement immediately after birth. The following variables were submitted to univariate analysis comparing Groups 1 and 2: maternal age, hypertensive syndrome, corticosteroid use (for lung maturation), gestational age at birth, and fetal vitality assessments on the day of delivery. The Doppler parameters analysed were: pulsatility index of the umbilical artery, middle cerebral artery and the pulsatility index for veins for the ductus venosus. The following variables of the fetal biophysical profile were obtained: cardiotocography or nonstress test ( normal/ abnormal), presence of late deceleration, presence of deceleration (late or severe variable decelerations, or prolonged bradycardia), absence of fetal breathing movements, presence of oligohydramnios and biophysical profile score (considered normal when the score was higher than 6). Clinically relevant and statistically significant variables were analyzed by logistic regression. The series included 46 patients divided in Group 1 (n=24 with acidosis) and Group 2 (n=22 without acidosis), and the following variables were statistically correlated to acidemia at birth (p0.05): maternal age, hypertensive syndrome, abnormal cardiotocographic findings, deceleration (late deceleration, or variable deceleration with poor prognosis, or prolonged deceleration), and absence of respiratory movements. On logistic regression, the presence of deceleration was predictive of acidemia (p=0,024; OR=8,2; CI95%=1,2-52). In conclusion, we believe that the presence of acidemia at birth in fetuses with umbilical artery positive diastolic flow and abnormal Doppler velocimetry is mainly associated with abnormality of acute parameters of fetal well-being. The finding of deceleration on cardiotocographic assessments was predictive of acidemia at birth. ____________________

Objetivo: Avaliar a relação entre a classificação do fluxo na onda a do ducto venoso no dia do parto e os resultados pós-natais em gestações com diástole zero ou reversa nas artérias umbilicais. Métodos: Analisou-se retrospectivamente a evolução pós-natal de 103 recém-nascidos de gestações com diagnóstico de diástole zero ou reversa à dopplervelocimetria das artérias umbilicais, no período de janeiro de 1997 a dezembro de 2004. Foram incluídas gestações únicas e fetos sem malformações. Nenhum caso recebeu corticoterapia antenatal. Os casos foram divididos em dois grupos de acordo com a classificação do fluxo na onda a do ducto venoso no dia do parto. Grupo A: 20 casos com fluxo ausente ou reverso e Grupo B: 83 casos com fluxo positivo. Foram avaliados os seguintes resultados pós-natais: idade gestacional no dia do parto, peso de nascimento, Apgar de primeiro e quinto minutos, pH e BE do sangue da artéria umbilical ao nascimento, necessidade de intubação orotraqueal e encaminhamento à unidade de terapia intensiva neonatal, além de: ocorrência de restrição de crescimento fetal, doença das membranas hialinas, pneumotórax, hemorragia pulmonar, displasia broncopulmonar, persistência do canal arterial, sepse, enterocolite necrosante, retinopatia da prematuridade, plaquetopenia, hipoglicemia, hiperglicemia, convulsão, exame neurológico anormal em 24 horas de vida, hemorragia intracraniana, os recém-nascidos foram avaliados durante toda a internação no berçário, sendo registrado o tempo de internação, ocorrência de óbito e causas do óbito. Para análise estatística foram utilizados os testes de Qui-Quadrado, exato de Fisher e Mann-Whitney U, adotado nível de significância de 5%. Resultados: Todos os partos foram cesareanos. A idade gestacional foi semelhante nos dois grupos, 30 semanas no grupo A e 30,9 semanas no B (P=0,23). Observou-se no grupo com fluxo ausente ou reverso da onda a do ducto venoso maior freqüência dos seguintes resultados pós-natais adversos: menor peso ao nascimento (831g vs 1.105g, P<0,001), menores índices de Apgar de primeiro minuto (85% vs 20%, P=0,001) e de quinto minuto (45% vs 10,7%, P =0,001), maior necessidade de intubação orotraqueal (100% vs 48,1%, P=0,001), maior ocorrência de acidose ao nascimento (93% vs 36%, P<0,001), hemorragia pulmonar (40% vs 16,8%, P=0,03), plaquetopenia (65% vs 37,3%, P=0,02), hipoglicemia (85% vs 56,6%, P=0,01), hemorragia intracraniana (52,6% vs 26,3%, P=0,02) e óbito pós natal (65% vs 26,5%, P=0,007). Conclusão: O estudo do fluxo no ducto venoso pode fornecer informações adicionais na programação do momento mais adequado para a interrupção de gestações que cursam com diástole zero ou reversa nas artérias umbilicais em gestações com prematuridade extrema. / Objective: This study was undertaken to analyze the relation between absent or reverse flow during atrial contraction in the ductus venosus on the day of delivery in pregnancies complicated by absent or reversed end-diastolic flow in the umbilical artery and postnatal outcome. Methods: Postnatal outcome of 103 pregnant women with absent or reversed end-diastolic flow (ARED flow) in the umbilical arteries was retrospectively analyzed from January 1997 to December 2004. In this study, only singleton pregnancies that did not take prenatal steroids and with no fetal anomalies were included. The outcome was analyzed in two groups: Group A (n=20), fetuses with absent or reversed ductus venosus flow during the A-wave and group B (n=83) fetuses with a positive flow. After delivery, the following immediate neonatal outcomes of interest were obtained: gestational age at the time of delivery, 1-and 5-minute Apgar scores, umbilical artery pH and base excess, birth weight, need of orotraqueal intubation, and referral to the neonatal intensive care unit. We have also analyzed the incidence of fetal growth restriction, hyaline membrane disease, pneumotorax, lung hemorrhage, bronchopulmonary displasia, persistence of the arterial channel, sepses, necrotizing enterocolitis, retinopathy of prematurity, fetal plaquetopenia, hypoglycemia, hyperglycemia, abnormal neurological exam within 24 hours of life, intracranial hemorrhage, seizures, length of hospitalization, postnatal deaths and its causes. Data were compared by chi-square, Fisher\'s exact test and a Mann-Whitney U test, and the level of significance adopted was of 5%. Results: All newborns were delivered by cesarean section. The average gestational age at birth was 30 weeks in group A and 30,9 in group B (P= 0.23). Fetuses of the group A presented lower birth weight (831g vs 1105g, P< 0.001), lower Apgar score at first (85% vs 20%, P= 0.001), and at fifth minutes (45% vs 10.7%, P =0.001), higher incidence of orotraqueal intubation (100% vs 48.1%, P= 0.001) than fetuses of group B. Group A had also more cases of acidosis (93% vs 36%, P<0.001), lung hemorrhage (40% vs 16,8%, P=0,03), plaquetopenia (65% vs 37.3%, P=0.02), hypoglycemia (85% vs 56.6%, P=0.01), intracranial hemorrhage (52.6% vs 26.3%, P=0.02) and postnatal death (65% vs 26.5%, P=0.007). Conclusion: Ductus venous Doppler can supply additional information regarding the better time to deliver pregnant women with earlier gestational age and with absent or reversed end-diastolic flow (ARED flow) in the umbilical artery.

No setor de Vitalidade Fetal na Clínica Obstétrica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo foi conduzido estudo caso-controle com seguimento prospectivo com quarenta e seis pacientes. O objetivo desse estudo foi identificar a associação dos testes de avaliação de vitalidade fetal e acidemia ao nascimento em gestações acometidas com dopplervelocimetria anormal e fluxo diastólico positivo das artérias umbilicais. Da mesma maneira, objetivou-se avaliar a relação entre os resultados antenatais, do parto, e neonatais com a ocorrência de pH fetal inferior a 7,20. A evolução para fluxo diastólico ausente ou reverso durante o seguimento foi critério de exclusão. Os casos foram classificados em dois grupos de acordo com a presença (grupo 1), ou ausência (grupo 2) de acidemia ao nascimento (pH inferior a 7,20), por meio da gasometria arterial de cordão imediatamente após o parto. As seguintes variáveis foram submetidas à análise univariada, comparando-se os grupos 1 e 2: idade materna, síndrome hipertensiva, uso de corticóde antenatal para maturação pulmonar, idade gestacional no momento do parto e testes de avaliação de vitalidade fetal do dia do parto. As modalidades dopplervelocimétricas analisadas foram: índice de pulsatilidade do território arterial (representado pela artéria umbilical e artéria cerebral média) e venoso (índice de pulsatilidade para veias do ducto venoso). Os seguintes parâmetros das atividades biofísicas fetais foram estudados: cardiotocografia (normal e anormal), presença de desaceleração tardia, presença de desaceleração (desaceleração tardia, ou desaceleração variável de mau prognóstico, ou desaceleração prolongada), ausência ou não de movimentos respiratórios, presença ou não de oligoâmnio e classificação do escore do perfil biofísico fetal (normal quando maior que 6, e anormal quando menor ou igual a 6). As variáveis clinicamente relevantes e estatisticamente significativas foram analisadas pela regressão logística. A série compôs-se de 46 pacientes classificadas nos grupos 1 (24 casos) e 2 (22 casos) e as seguintes variáveis foram estatisticamente relacionadas à ocorrência de acidemia no nascimento (p0,05): idade materna, síndrome hipertensiva, cardiotocografia anormal, presença de desaceleração, e ausência de movimentos respiratórios. Na regressão logística, a presença de desaceleração foi preditora de acidemia (p=0,024; OR=8,2; IC95%=1,2-52). Os presentes achados sustentam que a presença de acidemia ao nascimento em fetos com dopplevelocimetria anormal e fluxo diastólico positivo das AU está associada principalmente à anormalidade nos parâmetros agudos da avaliação da vitalidade fetal. A presença de desaceleração no traçado cardiotocográfico foi preditora de acidemia ao nascimento. / A longitudinal prospective study was conducted on 46 pregnancies with umbilical artery abnormal pulsatility index and positive diastolic flow velocity. Patients were evaluated at the Fetal Surveillance Unit/ Obstetrics Clinics of the University of São Paulo Medical School General Hospital (HCFMUSP) between February 2007 and March 2009. The objective of this study was to identify a potential association between fetal antenatal surveillance tests and acidemia at birth, in pregnancies with umbilical artery abnormal Doppler velocimetry and positive diastolic flow. In the same context, this research aimed to establish the correlation of data of birth, and neonatal outcome with umbilical cord pH below 7,20. The development of reversed or absent end- diastolic flow velovity in the umbilical artery was an excluision criteria. The cases were divided in two groups, according to the presence (Group 1) or absence (Group 2) of acidemia at birth (pH below 7.20), based on umbilical cord blood gas measurement immediately after birth. The following variables were submitted to univariate analysis comparing Groups 1 and 2: maternal age, hypertensive syndrome, corticosteroid use (for lung maturation), gestational age at birth, and fetal vitality assessments on the day of delivery. The Doppler parameters analysed were: pulsatility index of the umbilical artery, middle cerebral artery and the pulsatility index for veins for the ductus venosus. The following variables of the fetal biophysical profile were obtained: cardiotocography or nonstress test ( normal/ abnormal), presence of late deceleration, presence of deceleration (late or severe variable decelerations, or prolonged bradycardia), absence of fetal breathing movements, presence of oligohydramnios and biophysical profile score (considered normal when the score was higher than 6). Clinically relevant and statistically significant variables were analyzed by logistic regression. The series included 46 patients divided in Group 1 (n=24 with acidosis) and Group 2 (n=22 without acidosis), and the following variables were statistically correlated to acidemia at birth (p0.05): maternal age, hypertensive syndrome, abnormal cardiotocographic findings, deceleration (late deceleration, or variable deceleration with poor prognosis, or prolonged deceleration), and absence of respiratory movements. On logistic regression, the presence of deceleration was predictive of acidemia (p=0,024; OR=8,2; CI95%=1,2-52). In conclusion, we believe that the presence of acidemia at birth in fetuses with umbilical artery positive diastolic flow and abnormal Doppler velocimetry is mainly associated with abnormality of acute parameters of fetal well-being. The finding of deceleration on cardiotocographic assessments was predictive of acidemia at birth. ____________________

Objetivo: Avaliar a relação entre a classificação do fluxo na onda a do ducto venoso no dia do parto e os resultados pós-natais em gestações com diástole zero ou reversa nas artérias umbilicais. Métodos: Analisou-se retrospectivamente a evolução pós-natal de 103 recém-nascidos de gestações com diagnóstico de diástole zero ou reversa à dopplervelocimetria das artérias umbilicais, no período de janeiro de 1997 a dezembro de 2004. Foram incluídas gestações únicas e fetos sem malformações. Nenhum caso recebeu corticoterapia antenatal. Os casos foram divididos em dois grupos de acordo com a classificação do fluxo na onda a do ducto venoso no dia do parto. Grupo A: 20 casos com fluxo ausente ou reverso e Grupo B: 83 casos com fluxo positivo. Foram avaliados os seguintes resultados pós-natais: idade gestacional no dia do parto, peso de nascimento, Apgar de primeiro e quinto minutos, pH e BE do sangue da artéria umbilical ao nascimento, necessidade de intubação orotraqueal e encaminhamento à unidade de terapia intensiva neonatal, além de: ocorrência de restrição de crescimento fetal, doença das membranas hialinas, pneumotórax, hemorragia pulmonar, displasia broncopulmonar, persistência do canal arterial, sepse, enterocolite necrosante, retinopatia da prematuridade, plaquetopenia, hipoglicemia, hiperglicemia, convulsão, exame neurológico anormal em 24 horas de vida, hemorragia intracraniana, os recém-nascidos foram avaliados durante toda a internação no berçário, sendo registrado o tempo de internação, ocorrência de óbito e causas do óbito. Para análise estatística foram utilizados os testes de Qui-Quadrado, exato de Fisher e Mann-Whitney U, adotado nível de significância de 5%. Resultados: Todos os partos foram cesareanos. A idade gestacional foi semelhante nos dois grupos, 30 semanas no grupo A e 30,9 semanas no B (P=0,23). Observou-se no grupo com fluxo ausente ou reverso da onda a do ducto venoso maior freqüência dos seguintes resultados pós-natais adversos: menor peso ao nascimento (831g vs 1.105g, P<0,001), menores índices de Apgar de primeiro minuto (85% vs 20%, P=0,001) e de quinto minuto (45% vs 10,7%, P =0,001), maior necessidade de intubação orotraqueal (100% vs 48,1%, P=0,001), maior ocorrência de acidose ao nascimento (93% vs 36%, P<0,001), hemorragia pulmonar (40% vs 16,8%, P=0,03), plaquetopenia (65% vs 37,3%, P=0,02), hipoglicemia (85% vs 56,6%, P=0,01), hemorragia intracraniana (52,6% vs 26,3%, P=0,02) e óbito pós natal (65% vs 26,5%, P=0,007). Conclusão: O estudo do fluxo no ducto venoso pode fornecer informações adicionais na programação do momento mais adequado para a interrupção de gestações que cursam com diástole zero ou reversa nas artérias umbilicais em gestações com prematuridade extrema. / Objective: This study was undertaken to analyze the relation between absent or reverse flow during atrial contraction in the ductus venosus on the day of delivery in pregnancies complicated by absent or reversed end-diastolic flow in the umbilical artery and postnatal outcome. Methods: Postnatal outcome of 103 pregnant women with absent or reversed end-diastolic flow (ARED flow) in the umbilical arteries was retrospectively analyzed from January 1997 to December 2004. In this study, only singleton pregnancies that did not take prenatal steroids and with no fetal anomalies were included. The outcome was analyzed in two groups: Group A (n=20), fetuses with absent or reversed ductus venosus flow during the A-wave and group B (n=83) fetuses with a positive flow. After delivery, the following immediate neonatal outcomes of interest were obtained: gestational age at the time of delivery, 1-and 5-minute Apgar scores, umbilical artery pH and base excess, birth weight, need of orotraqueal intubation, and referral to the neonatal intensive care unit. We have also analyzed the incidence of fetal growth restriction, hyaline membrane disease, pneumotorax, lung hemorrhage, bronchopulmonary displasia, persistence of the arterial channel, sepses, necrotizing enterocolitis, retinopathy of prematurity, fetal plaquetopenia, hypoglycemia, hyperglycemia, abnormal neurological exam within 24 hours of life, intracranial hemorrhage, seizures, length of hospitalization, postnatal deaths and its causes. Data were compared by chi-square, Fisher\'s exact test and a Mann-Whitney U test, and the level of significance adopted was of 5%. Results: All newborns were delivered by cesarean section. The average gestational age at birth was 30 weeks in group A and 30,9 in group B (P= 0.23). Fetuses of the group A presented lower birth weight (831g vs 1105g, P< 0.001), lower Apgar score at first (85% vs 20%, P= 0.001), and at fifth minutes (45% vs 10.7%, P =0.001), higher incidence of orotraqueal intubation (100% vs 48.1%, P= 0.001) than fetuses of group B. Group A had also more cases of acidosis (93% vs 36%, P<0.001), lung hemorrhage (40% vs 16,8%, P=0,03), plaquetopenia (65% vs 37.3%, P=0.02), hypoglycemia (85% vs 56.6%, P=0.01), intracranial hemorrhage (52.6% vs 26.3%, P=0.02) and postnatal death (65% vs 26.5%, P=0.007). Conclusion: Ductus venous Doppler can supply additional information regarding the better time to deliver pregnant women with earlier gestational age and with absent or reversed end-diastolic flow (ARED flow) in the umbilical artery.

Objetivo: Avaliar o comportamento da dopplervelocimetria de artérias umbilicais, artéria cerebral média e ducto venoso após utilização de corticoterapia antenatal para maturação pulmonar fetal em casos de diástole zero à dopplervelocimetria das artérias umbilicais. Métodos: Analisaram-se de forma prospectiva 22 gestações com diagnóstico de diástole zero à dopplervelocimetria das artérias umbilicais, no período de maio de 2004 a fevereiro de 2006. Foram incluídas gestações únicas com fetos sem malformações, idade gestacional de 26 a 34 semanas e com indicação para utilização de corticóide antenatal para maturação pulmonar fetal (betametasona - 12mg/dia por dois dias) e posterior resolução da gestação. Para uso do referido medicamento foi necessária a presença de ao menos uma das seguintes condições: valores do ducto venoso (índice de pulsatilidade para veias - IPV) de 1 a 1,5 ou oligoâmnio (índice de líquido amniótico inferior a 5,0 cm). Foram analisados os índices de pulsatilidade das artérias umbilicais, artéria cerebral média e ducto venoso antes da primeira dose do corticóide (D0), 24 horas (D1) e 48 horas (D2) após a primeira dose de betametasona. Para análise estatística foi utilizado o teste de análise de variância com medidas repetidas e adotado nível de significância de 5%. Resultados: Em todos os casos realizaram-se cesarianas em intervalo de 24 a 36 horas após a segunda dose de corticóide. A média de idade gestacional no parto foi de 29,09 (±1,94) semanas e de peso no nascimento de 800,90 (±246,49) gramas. Em 19 (86,3%) casos verificou-se diminuição dos valores do índice de pulsatilidade no sonograma das artérias umbilicais, sendo que em 15 (68,1%) houve retorno do fluxo diastólico final. A média dos índices de pulsatilidade das artérias umbilicais no D0 foi 2,91 (±0,59); no D1: 2,16 (±0,63) e no D2: 2,54 (±0,74), com diferença significativa do D0 para D1 (p<0,001). Não houve modificações significativas na dopplervelocimetria da artéria cerebral média nas 48 horas subseqüentes ao uso de corticóide (p=0,686). Na dopplervelocimetria do ducto venoso notou-se diminuição dos valores do índice de pulsatilidade para veias, com as seguintes médias: D0: 1,02 (±0,26), D1: 0,71 (±0,16), D2: 0,69 (±0,13). Nota-se diminuição significativa dos valores de IPV do ducto venoso à comparação do D0 com D1 (p<0,001) e do D0 com D2 (p<0,001). Conclusão: Houve diminuição significativa dos índices de pulsatilidade da artéria umbilical e de pulsatilidade para veias do ducto venoso nas primeiras 24 horas após o uso de betametasona. Os índices de pulsatilidade da artéria cerebral média não apresentaram modificações significativas nas 48 horas subseqüentes ao uso de corticóide Verificou-se, também, ausência de modificações significativas no índice de pulsatilidade para veias do ducto venoso quando comparados os valores referentes ao D1 com aqueles encontrados no D2. / Objective: To evaluate the Doppler velocimetry findings in the umbilical arteries, middle cerebral artery and ductus venosus after prenatal corticosteroid therapy for fetal lung maturation in cases of absent end-diastolic umbilical artery Doppler flow. Methods: Twenty-two pregnancies with a diagnosis of absent end-diastolic umbilical artery Doppler flow were analyzed prospectively between May 2004 and February 2006. Included were single pregnancies with a gestational age of 26 to 34 weeks, whose fetuses showed no malformations and which had an indication for prenatal corticosteroid therapy for fetal lung maturation (12 mg/day betamethasone for 2 days) and subsequent pregnancy resolution. The use of the drug was necessary when at least one of the following conditions was present: ductus venosus flow velocity (pulsatility index for veins) of 1 to 1.5 or oligohydramnios (amniotic fluid index less than 5.0 cm). The pulsatility index of the umbilical arteries, middle cerebral artery and ductus venosus was determined before (D0) and 24 h (D1) and 48 h (D2) after the first betamethasone dose. The results were analyzed statistically by repeated measures analysis of variance, with the level of significance set at 5%. Results: A cesarian section was performed at an interval of 24 to 36 h after the second corticosteroid dose in all cases. The mean gestational age at delivery was 29.09 weeks (±1.94) and the mean birthweight was 800.90 g (±246.49). A decrease in the umbilical artery pulsatility index was observed in 19 (86.3%) cases, with a return of end-diastolic flow in 15 (68.1%). The mean umbilical artery pulsatility index was 2.91 (±0.59) at D0, 2.16 (±0.63) at D1, and 2.54 (±0.74) at D2, with a significant difference between D0 and D1 (p<0.001). No significant changes in the Doppler velocimetry findings of the middle cerebral artery was observed over the 48 h after corticosteroid administration (p=0.686). Ductus venosus Doppler velocimetry showed a decrease in the vein pulsatility index (D0: 1.02 (±0.26), D1: 0.71 (±0.16), D2: 0.69 (±0.13)) (p<0.001). There was a significant decrease in the vein pulsatility index of the ductus venosus between D0 and D1 (p<0.001) and between D0 and D2 (p<0.001). Conclusion: A significant decrease in the umbilical artery pulsatility index and in the vein pulsatility index of the ductus venosus was observed within the first 24 h after betamethasone administration. No significant changes in the Doppler velocimetry findings of the middle cerebral artery was observed over the 48 h after corticosteroid administration In addition, the ductus venosus pulsatility index values remained unchanged when comparing D1 and D2.

Objetivo: Avaliar o comportamento da dopplervelocimetria de artérias umbilicais, artéria cerebral média e ducto venoso após utilização de corticoterapia antenatal para maturação pulmonar fetal em casos de diástole zero à dopplervelocimetria das artérias umbilicais. Métodos: Analisaram-se de forma prospectiva 22 gestações com diagnóstico de diástole zero à dopplervelocimetria das artérias umbilicais, no período de maio de 2004 a fevereiro de 2006. Foram incluídas gestações únicas com fetos sem malformações, idade gestacional de 26 a 34 semanas e com indicação para utilização de corticóide antenatal para maturação pulmonar fetal (betametasona - 12mg/dia por dois dias) e posterior resolução da gestação. Para uso do referido medicamento foi necessária a presença de ao menos uma das seguintes condições: valores do ducto venoso (índice de pulsatilidade para veias - IPV) de 1 a 1,5 ou oligoâmnio (índice de líquido amniótico inferior a 5,0 cm). Foram analisados os índices de pulsatilidade das artérias umbilicais, artéria cerebral média e ducto venoso antes da primeira dose do corticóide (D0), 24 horas (D1) e 48 horas (D2) após a primeira dose de betametasona. Para análise estatística foi utilizado o teste de análise de variância com medidas repetidas e adotado nível de significância de 5%. Resultados: Em todos os casos realizaram-se cesarianas em intervalo de 24 a 36 horas após a segunda dose de corticóide. A média de idade gestacional no parto foi de 29,09 (±1,94) semanas e de peso no nascimento de 800,90 (±246,49) gramas. Em 19 (86,3%) casos verificou-se diminuição dos valores do índice de pulsatilidade no sonograma das artérias umbilicais, sendo que em 15 (68,1%) houve retorno do fluxo diastólico final. A média dos índices de pulsatilidade das artérias umbilicais no D0 foi 2,91 (±0,59); no D1: 2,16 (±0,63) e no D2: 2,54 (±0,74), com diferença significativa do D0 para D1 (p<0,001). Não houve modificações significativas na dopplervelocimetria da artéria cerebral média nas 48 horas subseqüentes ao uso de corticóide (p=0,686). Na dopplervelocimetria do ducto venoso notou-se diminuição dos valores do índice de pulsatilidade para veias, com as seguintes médias: D0: 1,02 (±0,26), D1: 0,71 (±0,16), D2: 0,69 (±0,13). Nota-se diminuição significativa dos valores de IPV do ducto venoso à comparação do D0 com D1 (p<0,001) e do D0 com D2 (p<0,001). Conclusão: Houve diminuição significativa dos índices de pulsatilidade da artéria umbilical e de pulsatilidade para veias do ducto venoso nas primeiras 24 horas após o uso de betametasona. Os índices de pulsatilidade da artéria cerebral média não apresentaram modificações significativas nas 48 horas subseqüentes ao uso de corticóide Verificou-se, também, ausência de modificações significativas no índice de pulsatilidade para veias do ducto venoso quando comparados os valores referentes ao D1 com aqueles encontrados no D2. / Objective: To evaluate the Doppler velocimetry findings in the umbilical arteries, middle cerebral artery and ductus venosus after prenatal corticosteroid therapy for fetal lung maturation in cases of absent end-diastolic umbilical artery Doppler flow. Methods: Twenty-two pregnancies with a diagnosis of absent end-diastolic umbilical artery Doppler flow were analyzed prospectively between May 2004 and February 2006. Included were single pregnancies with a gestational age of 26 to 34 weeks, whose fetuses showed no malformations and which had an indication for prenatal corticosteroid therapy for fetal lung maturation (12 mg/day betamethasone for 2 days) and subsequent pregnancy resolution. The use of the drug was necessary when at least one of the following conditions was present: ductus venosus flow velocity (pulsatility index for veins) of 1 to 1.5 or oligohydramnios (amniotic fluid index less than 5.0 cm). The pulsatility index of the umbilical arteries, middle cerebral artery and ductus venosus was determined before (D0) and 24 h (D1) and 48 h (D2) after the first betamethasone dose. The results were analyzed statistically by repeated measures analysis of variance, with the level of significance set at 5%. Results: A cesarian section was performed at an interval of 24 to 36 h after the second corticosteroid dose in all cases. The mean gestational age at delivery was 29.09 weeks (±1.94) and the mean birthweight was 800.90 g (±246.49). A decrease in the umbilical artery pulsatility index was observed in 19 (86.3%) cases, with a return of end-diastolic flow in 15 (68.1%). The mean umbilical artery pulsatility index was 2.91 (±0.59) at D0, 2.16 (±0.63) at D1, and 2.54 (±0.74) at D2, with a significant difference between D0 and D1 (p<0.001). No significant changes in the Doppler velocimetry findings of the middle cerebral artery was observed over the 48 h after corticosteroid administration (p=0.686). Ductus venosus Doppler velocimetry showed a decrease in the vein pulsatility index (D0: 1.02 (±0.26), D1: 0.71 (±0.16), D2: 0.69 (±0.13)) (p<0.001). There was a significant decrease in the vein pulsatility index of the ductus venosus between D0 and D1 (p<0.001) and between D0 and D2 (p<0.001). Conclusion: A significant decrease in the umbilical artery pulsatility index and in the vein pulsatility index of the ductus venosus was observed within the first 24 h after betamethasone administration. No significant changes in the Doppler velocimetry findings of the middle cerebral artery was observed over the 48 h after corticosteroid administration In addition, the ductus venosus pulsatility index values remained unchanged when comparing D1 and D2.