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Biomedical subjects

G Pardi

Publications and source records attributed to G Pardi.

At least 91 records · Page 5Linked to original sources
PubMed1988

Umbilical amino acid concentrations in appropriate and small for gestational age infants: a biochemical difference present in utero.

Plasma amino acid concentrations were determined in 28 pregnant women and their infants at term. Samples were obtained from 17 appropriate for gestational age and eight small for gestational age infants at cesarean section, while three small for gestational age fetuses were studied in utero by transabdominal cord sampling by means of ultrasonic guidance. Small for gestational age fetuses have significantly lower concentrations of alpha-aminonitrogen, compared with those of appropriate for gestational age fetuses, in both the umbilical artery and vein. Most of the difference is accounted for by the branched chain amino acids valine, leucine, and isoleucine. In contrast, hydroxyproline concentration is significantly higher in both the umbilical artery and vein of small for gestational age fetuses. The sum of the branched chain amino acid concentrations in the umbilical vein is directly related to maternal arterial values in both appropriate for gestational age and small for gestational age fetuses. Maternal arterial concentrations were slightly lower in small for gestational age fetuses and the regression analysis of umbilical venous versus maternal arterial branched chain amino acid concentrations was significantly different for small for gestational age and appropriate for gestational age infants. Umbilical venoarterial concentration differences in normal fetuses are significantly positive for most essential amino acids and for total alpha-aminonitrogen. In contrast, these differences were significant only for four essential amino acids in small for gestational age infants, while the total alpha-aminonitrogen venoarterial difference was not significant. The data obtained by transabdominal cord sampling from relatively undisturbed fetuses were in agreement with the data obtained at cesarean section; this information suggests that these differences between small for gestational age and appropriate for gestational age infants reflected steady-state conditions.

Amino Acids↗
PubMed1988

The relationship of maternal and fetal glucose concentrations in the human from midgestation until term.

The relationship between maternal and fetal glucose concentrations was investigated in pregnant women at different gestational ages. Maternal and fetal blood samples were obtained during 14 fetoscopies (17 to 21 weeks), four umbilical cord samples (32 to 36 weeks), nine elective cesarean sections with appropriate for gestational age (AGA) fetuses (35 to 39 weeks) and nine elective cesarean sections with small for gestational age (SGA) fetuses (34 to 37 weeks). A significant linear relationship between maternal and fetal glucose concentrations was demonstrated at midgestation (P less than .001) and at late gestation (P less than .001). At equal maternal concentrations there were no significant differences in fetal glucose concentration between the cord samples obtained in late gestation and those obtained at cesarean section. At midgestation fetal glucose concentration is independent of and may exceed maternal concentration at maternal glucose levels less than 4.44 mmol/L. Furthermore, the relationship between maternal and fetal concentrations at maternal glucose concentrations greater than 4.44 mmol/L is significantly different at midgestation from that at late gestation (P less than .01); at equal maternal concentrations there were higher glucose concentrations in the mid trimester fetus. In late gestation as the maternal glucose concentration increases there is an increase in the maternal arterial-umbilical arterial glucose concentration difference and the umbilical glucose/oxygen quotient (P less than .003) reflecting increased glucose utilization by the fetus. There were no significant differences between AGA and SGA babies with respect to these relationships.

Blood Glucose↗
PubMed1987

Cord sampling for the evaluation of oxygenation and acid-base balance in growth-retarded human fetuses.

In 14 pregnancies complicated by intrauterine growth retardation, the umbilical cord was sampled before delivery under ultrasonic guidance for rapid fetal karyotyping. Fetal blood was analyzed for respiratory gases, acid-base balance, and lactate concentrations. Two patients were excluded from the study because cord samples were diluted with amniotic fluid. In six patients (group 1), the clinical assessment warranted continuation of pregnancy. Cesarean sections were performed in the remaining eight patients (group 2) within 8 hours of cord sampling. The data from the two groups were compared with those obtained from umbilical venous blood at the time of elective repeat cesarean section in term appropriate for gestational age infants (controls). No significant difference in PO2 was found between groups 1 and 2 and controls. In contrast, there were significant differences in oxygen saturation and acid-base balance between groups 1 and 2. Lactate concentration was inversely correlated with pH and was elevated in five of six fetuses requiring a prompt cesarean section: In two of these five fetuses, nonstress fetal heart rate tracings were reactive. The results suggest that fetal blood biochemistry, and particularly lactate concentration, may represent an additional indicator of fetal well-being in pregnancies complicated by intrauterine growth retardation.

Acid-Base Equilibrium↗
PubMed1987

Respiratory gases, acid-base balance and lactate concentrations of the midterm human fetus.

Respiratory gases, acid-base balance, and lactate and hemoglobin concentrations were measured in 14 fetal blood samples between 17 and 21 weeks of gestation. The samples were obtained at the time of fetoscopy performed for prenatal diagnosis. Results have been compared with two reference groups: (a) 4 patients in whom fetal cord blood sampling was performed at 32-36 weeks of gestation, and (b) 10 patients at the time of elective cesarean section, 35-39 weeks. PO2 and oxygen saturations were significantly higher and hemoglobin concentration lower in the mid-gestation fetus. Acid-base balance was not significantly different. There was a significant correlation between maternal and fetal hemoglobin concentrations. The oxygen affinity of fetal blood was not significantly different from that described for term fetuses with a oxygen saturation of less than 90%.

Acid-Base Equilibrium↗
PubMed1987

Perinatal management of fetal hydronephrosis with normal bladder.

This report covers 30 cases of prenatal diagnosis of uni- or bilateral hydronephrosis not associated with an overdistended bladder. Oligohydramnios was observed only in four cases while polyhydramnios occurred in three affected fetuses. In no case was fetal urine aspirated or drained prenatally. Early delivery was performed in four cases with oligohydramnios. Sixteen newborns required surgical correction of the lesion as it was confirmed by urography, following at least two sonographic examinations which confirmed a moderate to severe hydronephrosis after birth. The most frequent lesion was pyelo-ureteric junction obstruction (12 cases). Thirteen cases were normal at follow-up, and in two of these the dilation cleared up during intrauterine life. One case of severe hydronephrosis proved to be a multicystic kidney. In this series isolated hydronephrosis, both uni- or bilateral did not result in fetuses being at high risk for survival (only one infant died after surgery) nor as regards to associated malformations and perinatal morbidity. Provided a properly timed surgical correction was performed, renal function resulted to be good at follow-up.

Cesarean Section↗
PubMed1986

Routine obstetric ultrasound: effectiveness of cross-sectional screening for fetal growth retardation.

Sonographic detection of fetal growth retardation was evaluated on a sample of 778 patients routinely scanned over a 16-month period. From the 29th week to term, the sensitivity of abdominal circumference measurement progressively increased from 41% to 88% (P less than 0.01). Higher rates were achieved by using the biparietal diameter but false-positive diagnoses were twice as frequent as with the abdominal measurements. When the limitations in precision of abdominal circumference were considered, the screening rate of this parameter increased about 16%. Moreover, 50% of the false-negative diagnoses were made on fetuses weighing between the fifth and 10th centiles at birth. These diagnostic indices for biparietal diameter and abdominal circumference evaluated on a retrospective series proved to be lower than those reported for the prospective selected series. However, the results yielded by routine ultrasound were better than those obtained with clinical or traditional biochemical methods. These findings underline the importance of sonography not only in serial control of high-risk pregnancies but also in cross-sectional screening programs.

Diagnostic Errors↗
PubMed1986

The intraventricular conduction time of fetal heart in pregnancies with suspected fetal growth retardation.

Electrocardiographs from 68 fetuses with ultrasound evidence of growth retardation were recorded from the maternal abdomen; QRS duration was measured and compared to normal standards previously obtained in our Institute. Of these fetuses, 54 were small-for-gestational-age at birth and 44 exhibited QRS duration values below -2 SD for their gestational age. All but one of the 14 normal fetuses showed normal QRS values (positive predictive value = 98%; negative predictive value = 57%). Of 11 fetuses with QRS duration values below -4 SD, nine were particularly small, below the 2nd centile of weight for gestation. QRS duration measurements may represent a sensitive method for identifying fetal growth-retardation. The QRS duration also seems to provide a reliable prognosis of perinatal outcome. Normal values are a reassuring factor: abnormal cardiotocographic records were observed in only 2 out of 23 cases and no low Apgar scores or perinatal deaths occurred. QRS values below -4 SD proved to be associated with abnormal cardiotocographic records (7/13), low Apgar scores (5/15) and perinatal deaths (3/15).

Birth Weight↗
PubMed1986

Pregnancy in women with chronic renal failure.

We describe 19 pregnancies in 18 women with chronic renal disease and plasma creatinine greater than or equal to 1.6 mg/dl before pregnancy. There were 2 spontaneous abortions (11th and 21st week), 2 therapeutic abortions (18th and 19th week), 1 stillbirth (30th week), 1 neonatal death (31st week) and 13 live births, 7 of them were preterm. Nine cesarean sections were done. Serial determinations of plasma creatinine during pregnancy showed a trend to decrease during the first half and to increase during the second half of pregnancy. The effect of pregnancy on the progression of renal failure was evaluated in 14 patients by comparing the linear regression lines of reciprocal plasma creatinine versus time before and after pregnancy. In 5 patients the rate of progression worsened after pregnancy. Our data indicate that women with chronic renal failure may have a successful pregnancy, but one third of them will have an accelerated rate of progression of the disease.

Abortion, Spontaneous↗
PubMed1986

Ultrasound contributions to the management of the severely isoimmunized fetus.

Twenty-four out of 81 fetuses affected by anti-D isoimmunization underwent ultrasonic guided intrauterine transfusions (2.8 I. U. T.s per fetus). The absolute value and trend of delta OD 450 micron value was correlated with the severity of fetal condition as evaluated by ultrasonography following simple semiquantitative grading of ascites (mild, moderate, severe) and diagnosis of hydrops. The evaluation of disease was monitored in this way during transfusion therapy. Transfusion procedures have been ultrasonically guided. When ascites was present a few milliliters of isolytic solution allowed the bubbling effect to be observed. In the case of no ascites we confirmed the needle positioning by a cineradiographic sequence lasting a few seconds. Fetal transfusions were repeated every 10 to 15 days and the amount of packed red cells to be injected was determined according to the week of gestation. Post-transfusion monitoring included ultrasonic reevaluation of fetal parameters and non-stress testing. All fetuses were delivered via cesarean section before the 35th week of gestation. In no case was treatment started after the 31st week. Seventeen fetuses were transfused before the 26th week (71%). In 13 fetuses transfusions were started before ascites had appeared. Only 5 fetuses worsened and the 3 which became hydropic eventually died. The delta OD-450 value of these 5 cases before therapy had already indicated that they were more severely affected. Survival rate in this group was 69%. Eleven fetuses showed different degrees of ascites or hydrops at the time of the first transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Transfusion, Intrauterine↗
PubMed1986

Accuracy of an average ultrasonic laboratory in measurements of fetal biparietal diameter, head circumference and abdominal circumference.

Twenty patients between 14 and 28 gestational weeks were scanned on three occasions during a single day by six operators with different ultrasonic experience (three use a compound scanner and three a real-time equipment). On each occasion every operator had to measure in a "blind" manner the fetal biparietal diameter (BPD), head circumference and abdominal circumference (HC and AC); a coded copy of head and abdominal circumference was subsequently measured by one of the members of the staff. Statistical analysis was carried out on the 1800 measurements, and it was concluded that the accuracy was not dissimilar from that reported by pilot studies. The reproducibility of the parameters studied did not change throughout pregnancy and real-time and compound scanner yielded homogeneous results.

Abdomen↗
PubMed1986

Variability analysis of fetal heart rate signals as obtained from abdominal electrocardiographic recordings.

The present paper introduces an original method of digital signal processing for an automatic analysis of non-invasive abdominal ECG recordings on pregnant women starting from the 25th week of gestation. The procedure has been implemented on a DEC-VAX 750 digital computer at the Department of Electrical Engineering, Polytechnic of Milano and the signals are recorded at the Department of Obstetrics and Gynecology "L. Mangiagalli", University of Milano, Italy. The experimental results presented in here are still preliminary as only few cases have been considered up to now (about 20) and the goal of the paper is mainly focused on the algorithmic aspects of the whole procedure implemented in the computer and on the approach of heart rate variability (HRV) signal analysis both in the mother and in the fetus. Abdominal ECG lead processing is illustrated starting from the step of maternal (M) and fetal (F) QRS recognitions through linear digital filtering (derivative and low-pass FIR filter, Weber-Cappellini window) and weighted averaging techniques synchronized with maternal QRS's. Figure 1 a shows the original abdominal lead; figure 1 b the filtered signal for MQRS recognitions; figure 2 a the template of maternal cardiac cycle as obtained after the averaging operation synchronized with the instants of MQRS occurrence. The subtraction of the template results in the abdominal lead shown in figure 1 c in which the contribution of MECG is practically entirely reduced even in the case of MQRS and FQRS overlapping.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography↗
PubMed1986

The clinical relevance of the abdominal fetal electrocardiogram.

We investigated the duration of fetal electrocardiographic events during normal pregnancies and during pregnancies with fetal abnormalities. The fetal abdominal signal was processed and enhanced by means of the averaging technique after removing the maternal complex. In normal pregnancies P wave and QRS complex duration increases progressively from the 17th week up to the term: this increase parallels the gain in weight of the fetal heart and particularly of the ventricular mass. These results indicated that the duration of fetal complexes could be used as an index of the size, development and maturity of the fetal heart. When fetal growth retardation (FGR) is present, the weight of the fetal heart is significantly reduced, and is reflected in a decrease in QRS duration. In a series of 107 cases the sensitivity of this parameter in detecting FGR was 81% and the specificity 93%. Moreover no perinatal death nor Apgar values below 7 occurred in growth retarded fetuses with normal QRS duration, while in the group with shortened QRS neonatal deaths were 11% and Apgar scores below 7 26%. Abdominal FECG do provide important auxiliary information for prenatal diagnosis of congenital heart defects (CHD). Anomalies with abnormal atrioventricular connection were reflected in longer PR interval. Ventricular hypertrophia and hypoplasia were associated with increased or decreased QRS duration, respectively. Furthermore, the three fetuses which developed congestive heart failure showed prolonged QRS duration. In severe RH disease, chronic fetal anemia can lead to myocardial hypertrophy and cardiac enlargement.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography↗
PubMed1985

Histocompatibility in Italian couples with recurrent spontaneous abortions of unknown origin and with normal fertility.

We investigated HLA antigen and haplotype frequencies in 47 couples with primary recurrent abortions of unknown origin, in 65 fertile couples, and in a control panel of 98 males and 92 females. A significant increase of HLA-B17 was found in abortion couples in comparison with fertile couples. No difference between abortion and control fertile couples was observed regarding HLA sharing.

Abortion, Habitual↗
PubMed1984

Lupus nephropathy and pregnancy. A study of 26 pregnancies in patients with systemic lupus erythematosus and nephritis.

We describe 26 pregnancies in 19 patients with lupus nephritis. There were 4 spontaneous abortions, 2 therapeutic abortions, 4 stillbirths and 1 neonatal death. 10 deliveries were preterm and 2 fetuses were small for gestational age. 8 pregnancies were not accompanied by change of renal symptoms. Mild signs of renal involvement appeared during pregnancy in 4 patients. 6 patients showed an increase in proteinuria already present before pregnancy without renal function deterioration. A moderate worsening of renal function was observed in 3 patients. 4 patients, 3 of whom had an apparent onset of systemic lupus erythematosus during pregnancy, developed anuric acute renal failure after delivery or after late spontaneous abortion. 2 of them died from sepsis and disseminated intravascular coagulation while 2 had complete recovery of renal function. A high rate of complications was observed in patients not adequately treated during pregnancy. Renal biopsy before gestation was not predictive of the outcome of nephropathy during pregnancy, and change of histology in repeated biopsies was frequently observed.

Abortion, Spontaneous↗