PubMed Health⌕ Search

Biomedical subjects

A Capponi

Publications and source records attributed to A Capponi.

At least 37 records · Page 2Linked to original sources
PubMed1996

The effects of fetal blood sampling on ventricular filling patterns: differences between normally grown and growth-retarded fetuses.

The objective of this study was to evaluate the effect of fetal blood sampling on atrioventricular blood flow velocity waveforms. Flow velocity waveforms were measured from mitral and tricuspid valve immediately before and after fetal blood sampling in 25 normally grown and 10 growth-retarded fetuses. This latter group was characterized by abnormal Doppler indices in umbilical artery and middle cerebral artery suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. The flow velocity parameters studied were peak velocity during early and active ventricular filling, time velocity integral, and fetal heart rate. Different indices were then calculated as expressions of ventricular diastolic function and cardiac output. In normally grown fetuses, both peak velocity during early diastole and time velocity integral values significantly increased after fetal blood sampling from both atrioventricular valves, whereas no significant changes were evidenced in the other parameters considered. Gestational age at the time of the procedure was positively related to the amplitude of these changes. In growth-retarded fetuses, fetal blood sampling induced a significant decrease in time velocity integral value form tricuspid valve, suggestive of a fall in right ventricle output. The amplitude of the decrease was significantly related to the severity of acidosis in umbilical vein. In conclusion, the cardiac hemodynamic response to fetal blood sampling differs between normally grown and growth-retarded fetuses. This difference may explain the higher rate of complications occurring in the latter group of fetuses after blood sampling.

Blood Flow Velocity↗
PubMed1996

Effects of cordocentesis on inferior vena cava velocity waveforms: differences between normally grown and growth-retarded fetuses.

The objective of this study was to analyze the effects of cordocentesis on velocity waveforms recorded from the inferior vena cava and to evaluate differences, if any, in the hemodynamic response between normally grown and growth-retarded fetuses. Twenty-five normally grown fetuses and 20 growth-retarded fetuses were considered for this study. This latter group was characterized by abnormal Doppler indices in the umbilical artery and the middle cerebral artery suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. Flow velocity waveforms were measured from the inferior vena cava immediately before and after cordocentesis and the % reverse flow during atrial contraction calculated. In normally grown fetuses the % reverse flow values did not vary significantly after cordocentesis, while in growth-retarded fetuses this index increased significantly after the procedure (p < or = 0.001). Furthermore, the amplitude of this increase was inversely related to pH levels in umbilical vein (p = 0.004). In conclusion, in growth-retarded fetuses cordocentesis induces an increase of % reverse flow in the inferior vena cava, while no modifications occur in normally grown fetuses. This suggests the presence in growth-retarded fetuses of an impaired cardiac adaptive mechanism to cordocentesis that may explain the higher incidence of complications occurring in such fetuses.

Blood Flow Velocity↗
PubMed1996

Uterine and fetal blood flows in pregnancies complicated by preterm labor.

Flow velocity waveforms were recorded by Doppler ultrasonography from the uterine arteries, umbilical artery, thoracic descending aorta, renal artery and middle cerebral artery in fetuses of 57 pregnancies complicated by preterm labor with intact membranes. The uterine artery resistance index was significantly increased in patients with preterm labor when compared to reference limits for gestation, but no relationship was found with the time interval between Doppler recordings and delivery. The group of fetuses (n = 15) delivered within 48 h from entry to the study showed significantly reduced pulsatility index values from the middle cerebral artery when compared to fetuses delivered later or to the normal reference limits for gestation. No significant differences were found in the other vessels studied. In conclusion preterm delivery is associated with alterations in fetal cerebral waveforms and knowledge of these changes may prove useful in the evaluation of patients with preterm labor.

Adult↗
PubMed1996

Fetal pH value determined by cordocentesis: an independent predictor of the development of antepartum fetal heart rate decelerations in growth retarded fetuses with absent end-diastolic velocity in umbilical artery.

Objective of this study was to establish the relationship in growth retarded fetuses between acid-base status in fetal blood obtained by cordocentesis and time interval between blood sampling and occurrence of antepartum heart rate late decelerations. Eighteen growth retarded fetuses scheduled for cordocentesis were considered for this study. All fetuses were free from structural and chromosomal abnormalities, characterized by absent end diastolic velocity waveforms in umbilical artery and later delivered for the development of antepartum heart rate late decelerations. Regression analysis showed that the time interval between cordocentesis and delivery was significantly related to pO2 (r = 0.46; p < or = 0.05) and pH (r = 0.57; p < or = 0.01) delta values but not with pCO2 values. Stepwise multiple regression analysis demonstrated that the severity of fetal acidosis significantly and independently predicted the length of this time interval even after controlling for confounding variables such as pO2 values, gestational age, presence of hypertension, or umbilical vein pulsations. The knowledge of this relationship may be useful in the clinical management of growth retarded fetuses.

Carbon Dioxide↗
PubMed1995

Blood levels of vasoactive intestinal polypeptide in normal and growth retarded fetuses: relationship with acid-base and haemodynamic status.

The objectives of this study were (1) to detect vasoactive intestinal polypeptide in fetal blood obtained by cordocentesis (2) to examine possible changes in growth retarded fetuses and to establish relationships between its levels and fetal blood acid-base status as well as fetal haemodynamics as assessed by Doppler ultrasonography. Vasoactive intestinal polypeptide was measured in umbilical vein blood obtained at cordocentesis in 12 growth retarded fetuses and in 13 control fetuses. Umbilical vein pH and PO2 values were determined in all the cases. Before the procedure, Doppler indices were calculated from umbilical artery, middle cerebral artery, renal artery, cardiac outflow tracts and inferior vena cava. Simple and multiple stepwise regression analysis were performed to examine the relationships between Doppler indices, acid-base status and vasoactive intestinal polypeptide levels. In control fetuses, vasoactive intestinal polypeptide was always detectable in cord blood and its levels did not change with gestational age. In growth retarded fetuses, vasoactive intestinal polypeptide levels were higher and significantly related to umbilical vein PO2 levels, Pulsatility Index in umbilical artery, middle cerebral artery and renal artery, while no relationship was found with umbilical vein pH, cardiac and venous Doppler indices. Stepwise multiple regression demonstrated middle cerebral artery Pulsatility Index to be the best explanatory variable for vasoactive intestinal polypeptide levels. In conclusion, vasoactive intestinal polypeptide blood levels are increased in growth retarded fetuses and this increase is inversely related to the Doppler measured impedance to flow in middle cerebral artery.

Acid-Base Equilibrium↗
PubMed1995

Cardiac flow after fetal blood sampling in normally grown and growth-retarded fetuses.

The objective of this study was to evaluate the effect of fetal blood sampling on cardiac flow velocity waveforms. Flow velocity waveforms were measured from the ascending aorta and pulmonary artery immediately before and after fetal blood sampling in 29 normally grown and 12 growth-retarded fetuses. The latter group was characterized by abnormal Doppler indices in the umbilical artery and middle cerebral artery suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. The flow velocity parameters studied were the peak velocity, the time to peak velocity, and the left and right cardiac output and their ratio. In normally grown fetuses, the peak velocity and right and left cardiac output values increased significantly after fetal blood sampling, while no significant changes were observed in the other indices considered. The gestational age at the time of the procedure was positively related to the amplitude of these changes. In growth-retarded fetuses, fetal blood sampling did not induce any significant increase in cardiac output or peak velocities, while in more than 50 per cent of the fetuses these Doppler indices decreased. The amplitude of the decrease was significantly related to the severity of acidosis in the umbilical vein. In conclusion, the cardiac haemodynamic response to fetal blood sampling differs between normally grown and growth-retarded fetuses. This difference may explain the higher rate of complications occurring in the latter group of fetuses after blood sampling.

Blood Flow Velocity↗
PubMed1995

Cardiac and venous blood flow in fetuses of insulin-dependent diabetic mothers: evidence of abnormal hemodynamics in early gestation.

OBJECTIVE: Our purpose was to determine whether in early gestation cardiac and venous blood flow patterns of fetuses of insulin-dependent diabetic mothers differ from those of normal fetuses. STUDY DESIGN: Serial recordings were obtained at 12, 16, and 20 weeks of gestation in 11 normal fetuses, 16 fetuses of insulin-dependent diabetic mothers with first-trimester glycosylated hemoglobin levels < or = 8.5% (group 1), and 11 fetuses of insulin-dependent diabetic mothers with first-trimester glycosylated hemoglobin levels > 8.5% (group 2). Velocity waveforms at the level of atrioventricular valves, inferior vena cava, and umbilical vein were recorded by means of color and pulsed Doppler equipment by either transvaginal or transabdominal approaches. The following variables were measured: ratio between the peak velocities during early passive ventricular filling and active atrial filling at the level of atrioventricular valves, percent reverse flow during atrial contraction in inferior vena cava, and pulsations in umbilical vein. RESULTS: In all the fetuses the ratios between early and active ventricular filling increased linearly with advancing gestation, whereas the percent reverse flow in the inferior vena cava decreased linearly. However, fetuses of diabetic mothers showed significant differences in the slope of the functions describing the development with gestation of these index values, resulting in lower values of the ratios between early and active ventricular filling at the level of both ventricular valves and higher values of percent reverse flow in inferior vena cava. These differences were more evident in group 2 fetuses of diabetic mothers, and statistically significant differences were found in the slope values compared with group 1 fetuses. In normal fetuses umbilical vein pulsations were present only in two fetuses at 12 weeks of gestation (18.18%) and were never evidenced later in gestation. A significantly higher incidence of pulsations was found at 12 weeks in fetuses of diabetic mothers (group 1, 56.25%; group 2, 81.81%) and pulsations were present until 16 weeks (group 1, 37.5%; group 2, 45.47%). CONCLUSIONS: An impaired development of cardiac and venous blood flow patterns occurs in fetuses in insulin-dependent diabetic mothers. These abnormalities are more evident in pregnancies with poorer glycemic control but still occur in the presence of stricter metabolic control.

Adult↗
PubMed1995

The effects of fetal blood sampling on ductus venosus blood flow velocity waveforms.

The objective of this study was to evaluate the effect of fetal blood sampling on ductus venosus hemodynamics. A secondary objective was to establish the relationship between the amplitude of these changes, if any, and different variables related either to the procedure of sampling or to fetal characteristics. The ratio was assessed between the systolic and atrial velocities from the ductus venosus that were measured immediately before and immediately after fetal blood sampling in 32 appropriately grown fetuses and in 12 growth-retarded fetuses. The latter group was characterized by abnormal Doppler indices in the umbilical artery and the middle cerebral artery, suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. The systolic/atrial ratio fell significantly after fetal blood sampling, but this decrease was less evident in growth-retarded fetuses. Neither the site of needling (placental cord insertion or intrahepatic vein) nor transplacental puncture during the procedure affected this decline. Similarly, fetal smallness, the volume of fetal blood aspirated and baseline values in Doppler indices from the ductus venosus and middle cerebral artery were unrelated to the observed changes. Stepwise regression analysis indicated that the variables that most significantly and independently affect the decline of the Doppler index were gestational age at the time of the procedure and pO2 values in the umbilical vein. In conclusion, modifications in ductus hemodynamics are induced by fetal blood sampling. These changes are less evident in hypoxemic growth-retarded fetuses and this reduced hemodynamic response may explain the higher rate of complications occurring in such fetuses after blood sampling.

Blood Flow Velocity↗
PubMed1995

Ventricular ejection force in growth-retarded fetuses.

The objective of this study was to determine whether in growth-retarded fetuses secondary to uteroplacental insufficiency the cardiac ventricles exert a force different from that of appropriately grown fetuses. Doppler echocardiographic studies were performed in 156 appropriately grown fetuses (gestational age 18-38 weeks) and in 72 growth-retarded fetuses (gestational age 24-36 weeks) free from structural and chromosomal abnormalities and characterized by Doppler changes in the umbilical artery and middle cerebral artery suggesting uteroplacental insufficiency as the most likely etiology of the growth defect. Right and left ventricular ejection force values were calculated from velocity waveforms recorded at the level of aortic and pulmonary valves, according to Newton's second law of motion. In appropriately grown fetuses, left and right ventricular ejection force values significantly increased with advancing gestation and the two ventricles exerted similar force. In growth-retarded fetuses, the ventricular ejection force was significantly and symmetrically decreased in both ventricles. Among growth-retarded fetuses, a poorer perinatal outcome was observed in those fetuses in which the ejection force of both ventricles was below the 5th centile of the normal limits for gestation. In 12 growth-retarded fetuses followed longitudinally during the last week preceding intrauterine death or Cesarean section due to antepartum heart-rate late decelerations, a significant decrease of ejection force was found in both ventricles. Finally, a significant relationship was found between the severity of acidosis and right and left ventricular ejection force values in 22 fetuses in which Doppler recordings were performed immediately before cordocentesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗
PubMed1995

Effects of thyrotropin releasing hormone on cardiac and extracardiac flows of appropriately grown and growth-retarded fetuses.

The objective of this study was to establish the effect of thyrotropin releasing hormone on the fetal circulation of appropriately grown and growth-retarded fetuses. Doppler recordings were performed immediately before and 15 min after maternal administration of 400 micrograms of thyrotropin releasing hormone in 14 women with appropriately grown and 19 with growth-retarded fetuses. Furthermore, in six women with growth-retarded fetuses, serial recordings were performed at 2-hourly intervals for 8 h until a second thyrotropin releasing hormone dose was administered. Velocity waveforms were recorded from the outflow tracts, inferior vena cava, umbilical artery, middle cerebral artery and descending aorta, and different Doppler indices calculated. In appropriately grown fetuses, thyrotropin releasing hormone induced a significant increase of peak systolic velocity values in the aorta and pulmonary artery and an increase of Doppler-estimated cardiac output. In growth-retarded fetuses, these changes were more evident and associated with a significant decrease in reverse flow in the inferior vena cava during atrial contraction. No changes were observed in fetal heart rate or in the other fetal vessels investigated. In the growth-retarded fetuses followed longitudinally, these changes were evident for the following 8 h and were potentiated by the second thyrotropin releasing hormone administration. In conclusion, thyrotropin releasing hormone induces significant hemodynamic effects on the fetal heart that may temporarily improve the impaired cardiac function of growth-retarded fetuses.

Adult↗
PubMed1995

Prenatal diagnosis of gastroesophageal reflux by color and pulsed Doppler ultrasonography in a case of congenital pyloric atresia.

A case of pyloric atresia diagnosed in the third trimester is described. Real-time ultrasonographic examination revealed polyhydramnios, enlarged stomach, evident gastric peristalsis and esophageal dilatation. Color and pulsed Doppler studies of the gastroesophageal junction revealed the presence of a biphasic flow pattern that was consistent with gastroesophageal reflux.

Adult↗
PubMed1995

The value of fetal arterial, cardiac and venous flows in predicting pH and blood gases measured in umbilical blood at cordocentesis in growth retarded fetuses.

OBJECTIVE: To assess the value of Doppler indices, calculated from fetal arterial peripheral vessels, cardiac outflow tracts and venous vessels, in the identification of acidaemia, hypercapnia and hypoxaemia as determined by pH and gas analysis of fetal blood obtained by cordocentesis in growth retarded fetuses. DESIGN: Doppler measurements were taken from umbilical artery, thoracic descending aorta, renal artery, middle cerebral artery, cardiac outflow tracts, inferior vena cava and ductus venosus immediately before cordocentesis. Logistic regression and receiver-operator characteristic curve analysis were performed to examine the relation between Doppler indices and acid-base status. SETTING: Tertiary centre for fetal medicine. SUBJECTS: Forty-eight growth retarded fetuses fulfilling these criteria for inclusion: 1. absence of chromosomal and structural anomalies; 2. an abdominal circumference or ultrasonographic estimated fetal weight less than the 5th centile; 3. presence of abnormal velocity waveforms in umbilical artery; and 4. postnatal confirmation of a birthweight below the 5th centile and absence of structural anomalies. RESULTS: The percentage of reverse flow in inferior vena cava was a more closely related variable for acidaemia (chi 2 = 29.69; P < or = 0.001) and hypercapnia (chi 2 = 12.86; P < or = 0.001) than the other Doppler indices. Hypoxaemia was better predicted by the pulsatility index from middle cerebral artery (chi 2 = 15.31; P < or = 0.001). CONCLUSION: The analysis of velocity waveforms from inferior vena cava and middle cerebral artery can be used to predict acid-base status in growth retarded fetuses secondary to placental insufficiency. This may lead to a more accurate antepartum monitoring of such fetuses.

Acidosis↗
PubMed1995

Umbilical vein pulsations and acid-base status at cordocentesis in growth-retarded fetuses with absent end-diastolic velocity in umbilical artery.

The objective of this study was to examine the acid-base status in blood obtained at cordocentesis in growth-retarded fetuses with absent end-diastolic velocity in the umbilical artery and divided according to the presence or absence of pulsations in the umbilical vein. Twenty-six growth-retarded fetuses free from structural and chromosomal abnormalities were considered for this study. All the fetuses had absent end-diastolic velocity in the umbilical artery associated in 11 cases (42.3%) with pulsations in the umbilical vein. Gas analysis of fetal blood obtained by cordocentesis was performed immediately after the Doppler recordings. Hypoxemia, acidemia and hypercapnia were defined respectively as the presence of pH or pO2 values 2 standard deviations below the normal mean for gestation and of pCO2 values 2 standard deviations above the normal mean for gestation. Fetuses with umbilical vein pulsations had lower values of pH (p < or = 0.001) and pO2 (p < or = 0.05) and higher values of pCO2 (p < or = 0.001) when compared to those without pulsations. All fetuses with pulsations were hypoxemic and hypercapnic and the incidence of acidemia was 90.9%. Fetuses with continuous blood flow in the umbilical vein, although frequently hypoxemic (80%), have pCO2 and pH values within the normal range in 40 and 52.3% of the cases, respectively. In conclusion, in fetuses with absent end-diastolic velocity in the umbilical artery the presence of umbilical vein pulsations identifies a subgroup of fetuses with a more severe compromise of acid-base status. This may be useful in the selection of the timing of delivery of such fetuses.

Blood Flow Velocity↗
PubMed1994

Ductus venosus velocity waveforms in appropriate and small for gestational age fetuses.

The objective of this study was to evaluate differences in ductus venosus velocity waveforms between appropriate and small for gestational age fetuses by using a new index based on the ratio between systolic and atrial peak velocities. Ductus venosus velocity waveforms were cross-sectionally recorded in 164 appropriate for gestational age fetuses at 16-42 weeks of gestation and in 97 small for gestational age fetuses free from structural and chromosomal abnormalities between 24-36 weeks of gestation. Small for gestational age fetuses were divided according to the Doppler findings in arterial peripheral vessels: group A (n = 33), normal ratio between umbilical artery and middle cerebral artery Pulsatility Indices; group B (n = 41), umbilical artery/middle cerebral artery ratio > 95th centile but presence of end diastolic flow in umbilical artery; group C (n = 23), umbilical artery/middle cerebral artery ratio > 95th centile and absence of end diastolic flow in umbilical artery. Eighteen small for gestational age fetuses (10 from group B and 8 from group C) were also serially studied until delivery due to fetal distress. Ductus venosus velocity waveforms were recorded at the level of its origin from umbilical vein and the ratio between systolic and atrial peak velocities (systolic/atrial ratio) calculated. In appropriate for gestational age fetuses, systolic/atrial ratio values significantly decrease with gestation. No significant differences were found in systolic/atrial ratio between appropriate for gestational age fetuses and group A small for gestational age fetuses while, after correction for gestational age, significantly higher values were found in group B (P < or = 0.01) and group C (P < or = 0.001) fetuses. Among these fetuses, those with systolic/atrial ratio above the 95th confidence interval showed a poorer perinatal outcome. No relationships were found between systolic/atrial ratio and Pulsatility Index values from fetal arterial peripheral vessels, while a positive relationship was found with the percentage reverse flow in inferior vena cava. In fetuses serially followed, the systolic/atrial ratio progressively increased approaching the onset of abnormal fetal heart rate patterns. The systolic/atrial ratio allows the evaluation of ductus venosus hemodynamics in small for gestational age fetuses and this index may be useful in the monitoring of such fetuses.

Aorta, Thoracic↗
PubMed1994

Does measurement of amniotic fluid index detect changes in amniotic fluid volume after second-trimester amniocentesis?

The objective of this study was to establish whether variations of amniotic fluid volume induced by second-trimester amniocentesis could be detected by serial measurements of amniotic fluid index. A total of 130 singleton pregnancies undergoing second-trimester amniocentesis for genetic indications were considered. Amniotic fluid index was measured at three different time intervals: 30-60 min before amniocentesis, immediately after the procedure, and 60 min after the procedure. Serial measurements were obtained either by a single operator (n = 55) or by the three independent operators (n = 75). Significantly lower amniotic fluid index values were demonstrated immediately after amniocentesis when compared with the pre-amniocentesis and subsequent measurements in the study design with both the single and multiple operators. No statistically significant changes were found between the first amniotic fluid index measurements and those obtained 1 h after amniocentesis. These results suggest that second-trimester amniocentesis induces a temporary decrease of amniotic fluid volume detectable by serial amniotic fluid index measurements, no longer evident 1 h after the procedure.

Journal Article↗
PubMed1994

Transverse cerebellar diameter in small-for-gestational-age fetuses: pregnancy dating is possible only when growth retardation is secondary to uteroplacental insufficiency.

The objective of this study was to establish whether measurement of the transverse cerebellar diameter to determine gestational age differs in small-for-gestational-age fetuses with normal or abnormal Doppler velocity waveforms. Our secondary objective was to compare the efficacy of measurement of transverse cerebellar diameter with that of femur length in pregnancy dating among small-for-gestational-age fetuses. A total of 107 small-for-gestational-age fetuses with established dates and free from structural and chromosomal abnormalities were considered for this study. According to the Doppler results, fetuses were divided into two groups: group A (n = 64), with normal Doppler values as expressed by a ratio of pulsatility indices between the umbilical artery and middle cerebral artery of 95th centile. Measurements of transverse cerebellar diameter and femur length were compared to previously established 95th centile prediction intervals. In both groups of small-for-gestational-age fetuses, the values for transverse cerebellar diameter were lower than in normally grown fetuses after normalization for gestational age. The difference was more evident in group A (p <or= 0.001) than in group B (p <or= 0.05). Only 68.7% of transverse cerebellar diameter values of group A fetuses fell within the normal limits for gestation, while this occurred in 90.6% of group B fetuses. When compared to the femur length, the transverse cerebellar diameter measurement appeared to be better for predicting gestational age in both groups of small-for-gestational-age fetuses (p <or= 0.001). However, this measurement may be used to estimate gestational age only in small-for-gestational-age fetuses with abnormal Doppler findings.

Journal Article↗