Heart rate, fetal Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Rev Bras Ginecol Obstet. 2010;32(9):420-425
DOI 10.1590/S0100-72032010000900002
PURPOSE: to compare the patterns of fetal heart rate (FHR) in the second and third trimesters of pregnancy. METHODS: a prospective and comparative study performed between January 2008 and July 2009. The inclusion criteria were: singleton pregnancy, live fetus, pregnant women without clinical or obstetrical complications, no fetal malformation, gestational age between 24 and 27 weeks (2nd trimester - 2T) or between 36 and 40 weeks (3rd trimester - 3T). Computerized cardiotocography (System 8002 - Sonicaid) was performed for 30 minutes and the fetal biophysical profile was obtained. System 8002 analyzes the FHR tracings for periods of 3.75 seconds (1/16 minutes). During each period, the mean duration of the time intervals between successive fetal heart beats is determined in milliseconds (ms); the mean FHR and also the differences between adjacent periods are calculated for each period. The parameters included: basal FHR, FHR accelerations, duration of high variation episodes, duration of low variation episodes and short-term variation. The dataset was analyzed by the Student t test, chi-square test and Fisher's exact test. Statistical significance was set at p<0.05. RESULTS: eighteen pregnancies on the second trimester were compared to 25 pregnancies on the third trimester. There was a significant difference in the FHR parameters evaluated by computerized cardiotocography between the 2T and 3T groups, regarding the following results: mean basal FHR (mean, 143.8 bpm versus 134.0 bpm, p=0.009), mean number of transitory FHR accelerations > 10 bpm (3.7 bpm versus 8.4 bpm, p <0.001) and >15 bpm (mean, 0.9 bpm versus 5.4 bpm, p <0.001), mean duration of high variation episodes (8.4 min versus 15.4 min, p=0.008) and mean short - term variation (8.0 ms versus 10.9 ms, p=0.01). The fetal biophysical profile showed normal results in all pregnancies. CONCLUSION: the present study shows significant differences in the FHR characteristics when the 2nd and 3rd trimesters of pregnancy are compared and confirms the influence of autonomic nervous system maturation on FHR regulation.
Summary
Rev Bras Ginecol Obstet. 2010;32(9):420-425
DOI 10.1590/S0100-72032010000900002
PURPOSE: to compare the patterns of fetal heart rate (FHR) in the second and third trimesters of pregnancy. METHODS: a prospective and comparative study performed between January 2008 and July 2009. The inclusion criteria were: singleton pregnancy, live fetus, pregnant women without clinical or obstetrical complications, no fetal malformation, gestational age between 24 and 27 weeks (2nd trimester - 2T) or between 36 and 40 weeks (3rd trimester - 3T). Computerized cardiotocography (System 8002 - Sonicaid) was performed for 30 minutes and the fetal biophysical profile was obtained. System 8002 analyzes the FHR tracings for periods of 3.75 seconds (1/16 minutes). During each period, the mean duration of the time intervals between successive fetal heart beats is determined in milliseconds (ms); the mean FHR and also the differences between adjacent periods are calculated for each period. The parameters included: basal FHR, FHR accelerations, duration of high variation episodes, duration of low variation episodes and short-term variation. The dataset was analyzed by the Student t test, chi-square test and Fisher's exact test. Statistical significance was set at p<0.05. RESULTS: eighteen pregnancies on the second trimester were compared to 25 pregnancies on the third trimester. There was a significant difference in the FHR parameters evaluated by computerized cardiotocography between the 2T and 3T groups, regarding the following results: mean basal FHR (mean, 143.8 bpm versus 134.0 bpm, p=0.009), mean number of transitory FHR accelerations > 10 bpm (3.7 bpm versus 8.4 bpm, p <0.001) and >15 bpm (mean, 0.9 bpm versus 5.4 bpm, p <0.001), mean duration of high variation episodes (8.4 min versus 15.4 min, p=0.008) and mean short - term variation (8.0 ms versus 10.9 ms, p=0.01). The fetal biophysical profile showed normal results in all pregnancies. CONCLUSION: the present study shows significant differences in the FHR characteristics when the 2nd and 3rd trimesters of pregnancy are compared and confirms the influence of autonomic nervous system maturation on FHR regulation.
Summary
Rev Bras Ginecol Obstet. 2009;31(11):547-551
DOI 10.1590/S0100-72032009001100004
PURPOSE: to study the effect of acoustic stimulation in the fetal cardiac response, according to parameters from computerized cardiotocography in low risk pregnancies. METHODS: twenty low risk pregnant women were included in the study, according to the following criteria: age over 18; single gestation, living fetus; gestational age between 36 and 40 weeks; amniotic liquid index over 8.0 cm and absence of fetal malformation. Cases with post-natal diagnosis of fetal anomaly were excluded. Computerized cardiotocography was performed for 20 minutes, before and after fetal acoustic stimulation. Results were analyzed by the t test for dependent samples, with significance level at p<0.05. RESULTS: acoustic stimulation was successfully performed in all cases analyzed. By the analysis of the cardiotocographic parameters, there was no significant difference when the pre and post-stimulation parameters were compared: average number of fetal movements per hour (55.6 versus 71.9, p=0.1); mean basal fetal heart rate (FHR) (135.2 versus 137.5 bpm, p=0.3); mean FHR increases>10 bpm (6.5 versus 6.8, p=0.7); mean FHR increases>15 bpm (3.8 versus 4.3, p=0.5); mean duration of high FHR variation episodes (11.4 versus 10.9 min, p=0.7); mean duration of low FHR variation episodes (2.5 versus 1.1 min, p=0.2), and mean short-term variation (10.6 versus 10.9 ms, p=0.6). CONCLUSIONS: in low risk gestations at term, computerized cardiotocography has not evidenced differences in the FHR parameters after the fetal sonic stimulation.
Summary
Rev Bras Ginecol Obstet. 2009;31(11):547-551
DOI 10.1590/S0100-72032009001100004
PURPOSE: to study the effect of acoustic stimulation in the fetal cardiac response, according to parameters from computerized cardiotocography in low risk pregnancies. METHODS: twenty low risk pregnant women were included in the study, according to the following criteria: age over 18; single gestation, living fetus; gestational age between 36 and 40 weeks; amniotic liquid index over 8.0 cm and absence of fetal malformation. Cases with post-natal diagnosis of fetal anomaly were excluded. Computerized cardiotocography was performed for 20 minutes, before and after fetal acoustic stimulation. Results were analyzed by the t test for dependent samples, with significance level at p<0.05. RESULTS: acoustic stimulation was successfully performed in all cases analyzed. By the analysis of the cardiotocographic parameters, there was no significant difference when the pre and post-stimulation parameters were compared: average number of fetal movements per hour (55.6 versus 71.9, p=0.1); mean basal fetal heart rate (FHR) (135.2 versus 137.5 bpm, p=0.3); mean FHR increases>10 bpm (6.5 versus 6.8, p=0.7); mean FHR increases>15 bpm (3.8 versus 4.3, p=0.5); mean duration of high FHR variation episodes (11.4 versus 10.9 min, p=0.7); mean duration of low FHR variation episodes (2.5 versus 1.1 min, p=0.2), and mean short-term variation (10.6 versus 10.9 ms, p=0.6). CONCLUSIONS: in low risk gestations at term, computerized cardiotocography has not evidenced differences in the FHR parameters after the fetal sonic stimulation.
Summary
Rev Bras Ginecol Obstet. 2009;31(10):513-526
DOI 10.1590/S0100-72032009001000008
The present context of medical practice demands from the obstetrician and gynecologist broad understanding of the scientific and technological advances of the area. The main purpose of prenatal evaluation is to identify fetuses at risk for adverse events or death, for preventive action to avoid mishappenings. The determination of fetal biophysical profile reaches its maximum efficiency when applied within the clinical context of each case. In high risk gestations, the Doppler velocimetry of the umbilical artery has shown to be useful to improve perinatal outcome. In the fetal growth deficit, due to severe placentary insufficiency, Doppler velocimetry of the venous duct has been showing to be an important tool in handling of the cases before the 34th week of gestation. Although no test itself is considered the best to evaluate the fetus's prenatal vitality, the joint analysis of all methods may lead to a better understanding of the fetal response to hypoxia.
Summary
Rev Bras Ginecol Obstet. 2009;31(10):513-526
DOI 10.1590/S0100-72032009001000008
The present context of medical practice demands from the obstetrician and gynecologist broad understanding of the scientific and technological advances of the area. The main purpose of prenatal evaluation is to identify fetuses at risk for adverse events or death, for preventive action to avoid mishappenings. The determination of fetal biophysical profile reaches its maximum efficiency when applied within the clinical context of each case. In high risk gestations, the Doppler velocimetry of the umbilical artery has shown to be useful to improve perinatal outcome. In the fetal growth deficit, due to severe placentary insufficiency, Doppler velocimetry of the venous duct has been showing to be an important tool in handling of the cases before the 34th week of gestation. Although no test itself is considered the best to evaluate the fetus's prenatal vitality, the joint analysis of all methods may lead to a better understanding of the fetal response to hypoxia.
Summary
Rev Bras Ginecol Obstet. 2006;28(12):693-699
DOI 10.1590/S0100-72032006001200002
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.
Summary
Rev Bras Ginecol Obstet. 2006;28(12):693-699
DOI 10.1590/S0100-72032006001200002
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.