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Biomedical subjects

G Pardi

Publications and source records attributed to G Pardi.

At least 73 records · Page 4Linked to original sources
PubMed1992

Venous drainage of the human uterus: respiratory gas studies in normal and fetal growth-retarded pregnancies.

OBJECTIVE: To determine respiratory gas relationships between the uterine veins and umbilical vein in normal and pregnancies complicated by intrauterine growth retardation. STUDY DESIGN: Respiratory gases were measured in both uterine veins and the umbilical vein in eight normal and 13 pregnancies with intrauterine growth retardation. RESULTS: No significant differences were found in the placental versus nonplacental uterine veins. There was a significant correlation for umbilical and uterine venous values of PO2 (p less than 0.002) and PCO2 (p less than 0.004) in appropriate-for-gestational-age pregnancies, umbilical venous PO2 was always less than uterine venous PO2, and PCO2 always greater than uterine. The transplacental gradient was significantly higher in intrauterine growth retarded than appropriate-for-gestational-age pregnancies for both POC2 and PCO2. There was a lower uterine oxygen extraction in intrauterine growth retarded pregnancies (p less than 0.05). CONCLUSION: There is no consistent relationship between placental venous drainage in each uterine vein and placental location. The human placenta simulates a relatively inefficient venous equilibrator and the larger transplacental gradients in intrauterine growth retarded pregnancies may reflect differences in both perfusion pattern and placental structure.

Blood Gas Analysis↗
PubMed1992

Malformations in offspring of 305 epileptic women: a prospective study.

This paper deals with malformations detected in 26 of 315 newborns of 305 epileptic mothers followed prospectively. In 3 more cases, malformations were detected in utero and therapeutic abortion was performed. Two hundred and seven women were on monotherapy, 102 on polytherapy and 9 were not treated. In total, malformations overall incidence was 9.1%. Minor anomalies were detected in 42 newborns (13.3%). A higher rate of malformations and minor anomalies was found among offspring of mothers treated with valproic acid (VPA). In the VPA group, mothers of malformed babies had higher plasma levels in the first trimester than mothers of babies without malformations. The need for accurate prenatal diagnostic studies in pregnant women with epilepsy is stressed.

Abnormalities, Drug-Induced↗
PubMed1991

Maternal predictors of HIV vertical transmission.

We performed a retrospective study of 57 HIV-positive pregnant women and their children to look for maternal parameters related to rates of vertical transmission of HIV. Sixteen (28%) infants were HIV-infected. There was no positive correlation between maternal risk factors for HIV and vertical transmission of HIV. Multiparity seemed to be related to a higher prevalence of vertical transmission, whereas neither preterm delivery nor cesarean section resulted in different rates of vertical transmission, although they tended to have some protective effect. Maternal beta 2-microglobulin and serum neopterin levels were not related to different rates of vertical transmission of HIV. CD4+ cell counts did so only when cut-off values of 400/mm3 were taken. All the women in CDC group IV and all the HIV p24 antigen-positive transmitted the infection to their infants, whereas only 7/48 women in CDC groups II and III (P = 0.000006) and 9/48 HIV p24 antigen negative women (P = 0.00006) gave birth to infected infants. No other maternal characteristics were associated with different rates of vertical transmission in a multivariate analysis restricted to women in CDC groups II and III and with HIV p24 antigen negativity.

Adult↗
PubMed1991

Doppler velocimetry: critical analysis of umbilical, cerebral and aortic reference values.

Cross-sectional reference standards of the umbilical flow velocity waveforms were investigated from 18 to 38 weeks of gestation on 482 normal pregnancies. A significant decrease in the pulsatility index (PI) and systolic/diastolic (SD) ratio was observed during gestation. This phenomenon was confirmed in a longitudinal study on 150 patients of the same population. The two slopes of cross-sectional and longitudinal data were not significantly different. A bimodal distribution of PI and S/D ratio was observed. Six per cent of data fell above the vast majority of cases. The dimension of the population studied allowed us to consider these findings not as outliers but as an interesting transient phenomenon of very low end-diastolic velocities which can occur in normal fetuses, without concomitant variations on the thoracic aorta and middle cerebral artery. Cross-sectional reference ranges were studied for these vessels on the same population from 26 to 38 weeks of gestation. A significant decrease in the PI of the middle cerebral artery was observed versus a significant increase in the PI of the thoracic aorta. These latter indices could be used to obtain indirect information on the normal redistribution of blood flow in the human fetus in the third trimester of gestation. However, the great variability observed should warn against the risks of a simplistic clinical use of these observations.

Aorta, Thoracic↗
PubMed1991

Maturation of hypothalamic-pituitary-gonadal function in normal human fetuses: circulating levels of gonadotropins, their common alpha-subunit and free testosterone, and discrepancy between immunological and biological activities of circulating follicle-stimulating hormone.

The recent availability of both cordocentesis, a low risk and effective technique for fetal blood sampling, and ultrasensitive/highly specific two-site immunofluorometric assays (IFMA) for pituitary and chorionic glycoprotein hormone (I-LH, I-FSH, and I-CG) measurement prompted us to study the maturation of hypothalamic-pituitary-gonadal function in 114 normal human fetuses (49 females and 65 males) from 17-40 weeks gestation. The subjects were selected from 216 consecutive cordocenteses carried out for rapid karyotyping and diagnosis of fetal infection or hematological disorders. In addition, FSH bioactivity (B-FSH) was measured by rat Sertoli cell aromatase induction assay, glycoprotein hormone alpha-subunit (alpha-SU) by RIA, and circulating free testosterone (fT) by direct analog technique. No significant cross-reactions were recorded in the different measurement methods. In particular, alpha-SU did not interfere in any IFMA, and CG cross-reactivity in LH IFMA was 0.5%. Circulating I-LH, I-FSH, and B-FSH levels at 17-24 weeks gestation were significantly higher in female than in male fetuses (I-LH, 48 +/- 4 vs. 6.3 +/- 0.7 U/L; I-FSH, 35 +/- 2 vs. 0.7 +/- 0.1 U/L; B-FSH, 131 +/- 17 vs. 43.4 +/- 5.4 U/L). During the last weeks of gestation, a significant decrease in I-LH and I-FSH levels was seen in both female and male fetuses (I-LH, 0.24 +/- 0.05 and 1.0 +/- 0.3 U/L; I-FSH, 0.45 +/- 0.1 and 0.5 +/- 0.1 U/L), while serum B-FSH remained elevated, but the previously recorded difference between sexes disappeared (54.3 +/- 7.2 and 58.7 +/- 7.3 U/L). Circulating I-CG and alpha-SU levels at midgestation were elevated in both female and male fetuses (I-CG, 117 +/- 29 and 191 +/- 44 U/L; alpha-SU, 143 +/- 16 and 105 +/- 9 micrograms/L, respectively) and decreased thereafter (I-CG, 42 +/- 9 and 26 +/- 6 U/L; alpha-SU, 60 +/- 15 and 37 +/- 6 micrograms/L). Serum fT levels at midgestation were significantly lower in females than in males (4.3 +/- 0.9 vs. 10.0 +/- 0.8 pmol/L) and increased until term, when the difference between sexes disappeared (16.2 +/- 1.8 vs. 17.6 +/- 1.6 pmol/L).(ABSTRACT TRUNCATED AT 400 WORDS)

Embryonic and Fetal Development↗
PubMed1990

Umbilical amino acid concentrations in normal and growth-retarded fetuses sampled in utero by cordocentesis.

Fetal plasma amino acid concentrations were obtained by cordocentesis at midgestation in 11 normal (appropriate for gestational age) fetuses and at late gestation in 12 small-for-gestational-age fetuses, and at cesarean section in 14 normal term infants. In normal fetuses total molar amino acid concentrations and fetal/maternal total molar concentration ratios did not change significantly between the second and third trimesters. Fetal and maternal concentrations of most amino acids were significantly correlated at both midgestation and late gestation. Small-for-gestational-age fetuses had significantly lower concentrations of total alpha-aminonitrogen; this was mainly because of a reduction of the branched chain amino acids valine, leucine, and isoleucine, and of lysine and serine. Maternal arterial concentrations of phenylalanine, arginine, histidine, and alanine were elevated in small-for-gestational-age pregnancies. Thus there are only minor changes in amino acid concentrations between midgestation and late gestation in normal fetuses with a constant fetal/maternal ratio. In small-for-gestational-age infants a significant reduction in alpha-aminonitrogen and in most essential amino acids was demonstrable in utero weeks before delivery.

Amino Acids↗
PubMed1990

Perinatal outcome in HIV-infected pregnant women.

We have observed 74 HIV-seropositive and 48 HIV-seronegative drug-addicted women and 22 HIV-seropositive nondrug-addicted pregnant women during pregnancy and we report their perinatal outcome. 8 out of 96 HIV-seropositive patients had hematological signs of immunodeficiency and 2 of these patients were symptomatic belonging to CDC class III. We recorded 2 early and 3 late spontaneous abortions, no intrauterine fetal death and 3 neonatal deaths. Seropositive patients had 3 malformed babies, seronegative patients had 1. All these women had a high incidence of premature delivery and intrauterine fetal growth retardation: seropositive patients had a higher incidence of fetuses small for gestational age and a lower incidence of preterm delivery compared to seronegative patients, but the difference was not statistically significant. The incidence of malformation was comparable to the general population: 3 malformed babies were born to HIV-positive drug-addicted mothers, and 1 to a seronegative drug-addicted mother. These findings do not support the hypothesis of a direct detrimental effect of HIV on perinatal outcome. Consequences of fetal exposure to maternal HIV infection involve mostly postnatal life and development of acquired immunodeficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Prenatal immune status of fetuses of HIV-seropositive mothers.

Human immunodeficiency virus (HIV) has been isolated from fetal tissues as early as 13 weeks and later from fetal blood. These findings have raised the possibility of prenatal diagnosis of infected fetuses by identification of the virus in the fetal compartment. Study of the fetal immune status has proved reliable in prenatal diagnosis of congenital immunodeficiency, and we have tested the possibility to diagnose acquired immunodeficiency in utero by this approach. We studied T lymphocyte subsets and their mitogenic response in fetal blood obtained after elective termination at midgestation in 8 cases and at delivery in 26 cases of maternal HIV infection. Results have been compared to appropriate normal controls. No significant difference was found in terms of total lymphocytes, CD4 and CD8 populations and phytohemagglutinin responses. This indicates either that immunological parameters currently used to assess postnatal immunodeficiency are not reliable during intrauterine life or that the intrauterine environment and the transplacental passage of maternal antibodies interfere with development of prenatal immunodeficiency.

AIDS Serodiagnosis↗
PubMed1990

Lactate metabolism in normal and growth-retarded human fetuses.

Lactate concentration and oxygen content were measured in 21 normal (AGA) and 34 intrauterine growth-retarded (IUGR) infants at the time of elective cesarean section. Maternal lactate and umbilical arterial and venous lactate concentrations were significantly higher in IUGR infants compared with AGA infants. However, when IUGR patients were subdivided according to pulsatility index (PI) measurements of the umbilical artery, no differences were detected between AGA and IUGR patients with PI less than 4 SD, whereas IUGR patients with PI greater than 4 SD had higher lactate concentrations in maternal arterial blood and umbilical arterial and venous blood from both other groups. There was a significant inverse linear relationship between umbilical arterial lactate concentration and umbilical venoarterial differences for both lactate concentrations and for lactate/oxygen quotients. These relationships were significantly different in IUGR fetuses with PI greater than 4 SD compared with AGA and IUGR fetuses with PI less than 4 SD. AGA and IUGR fetuses with PI less than 4 SD have arterial lactate concentrations less than 2 mM even at low oxygen concentrations (O2 content less than 2 mM, O2 saturations less than 20%). At comparable levels of oxygenation, IUGR fetuses with PI greater than 4 SD have a marked lactacidemia. The data suggest that coupling Doppler assessment of flow velocimetry with biochemical analyses of fetal blood can be useful in identifying a subset of IUGR human fetuses at risk of intrauterine hypoxia.

Female↗
PubMed1989

Umbilical flow waveforms versus fetal biophysical profile in hypertensive pregnancies.

The pulsatility index (PI) of the umbilical arteries was measured in 40 hypertensive pregnancies. Doppler-velocimetric data were kept unknown to the clinical staff. An abnormal PI was found in 79% of cases in which an abnormal fetal growth in utero had been diagnosed by ultrasonographic measurements. Serial PI findings showed worsening figures in most of the cases with an abnormal fetal growth, irrespective of the last absolute value. Amniotic fluid estimation and PI data were significantly correlated. PI values were markedly abnormal in fetuses with non-reactive heart-rate tracings. A high sensitivity and an optimal specificity were found for umbilical PI versus the diagnosis of fetal growth retardation made by the coexistence of different biophysical criteria. However, false normal results may occur. 62% of the newborns weighed below the 5th percentile. The sensitivity of abnormal PI values to detect these light fetuses resulted to be only 67%. However the prevalence of neonatal morbidity in fetuses with abnormal PI values was 74%, while morbidity occurred only in 14% of cases with normal PI values. In hypertensive pregnancies, this simple velocimetric parameter proved to correlate with abnormal biophysical monitoring and complicated neonatal outcomes.

Birth Weight↗
PubMed1989

Spectral analysis of antepartum heart rate variability.

The present paper illustrates the basic methodological aspects of the power spectral analysis applied to fetal ECG starting from a gestational age around the 25th week of gestation until term. An abdominal ECG signal is recorded and fetal and maternal QRSs are recognised through selective digital filtering and averaging techniques. Power Spectral Density (PSD) of the discrete R-R series is then calculated through an autoregressive (AR) technique. In analogy with what happens in adult human subjects, fetuses manifest variability in correspondence to particular bands in the spectrum which are sensitive to the sympatho-vagal balance which controls many cardiovascular functions and respiration in different physiological conditions. Such a method is easily implemented on a personal computer and may be used to asses the development of the autonomic nervous system in fetuses as well as to show the physiopathological reasons which perturbate the relevant control mechanisms.

Cardiotocography↗
PubMed1989

Power spectral analysis of the heart rate of the human fetus at 26 and 36 weeks of gestation.

The fetal electrocardiogram (ECG) was recorded from the maternal abdomen together with sonographic detection of fetal states in four pregnant patients at 26 and 36 weeks of gestation. Computerised algorithms obtained a good recognition of maternal ECG and fetal ECG. The corresponding power spectral density (PSD) was estimated during epochs of quiet or breathing movements for 256 consecutive heart beats. At 36 weeks of gestation the PSD analysis showed heart rate variability components similar to an adult heart. A low frequency component was observed together with a high frequency component in the range of fetal breathing movements. This high frequency component (0.6 - 0.9 Hz) disappeared from the PSD analysis during epochs of apnea. To our knowledge this is the first demonstration of such a mechanism in the human fetus in utero. At 26 weeks no respiratory component was observed in the PSD analysis. The maturation of control mechanisms could be responsible for this difference.

Electrocardiography↗
PubMed1989

Effect of prednisone and heparin treatment in 14 patients with poor reproductive efficiency related to lupus anticoagulant.

In women with a previous intrauterine fetal death related to lupus anticoagulant (LAC), we studied the effect of prednisone and calcieparine treatment to enable longer intrauterine life, increased fetal growth and increased survival rate. LAC was determined by the kaolin clotting time and was associated with elevated levels of antinuclear and anticardiolipin antibody in 42% and 21% of the cases, respectively. 14 women entered the study; they had a past history of 27 pregnancies, with only 1 small-for-gestational age (SGA) liveborn. The mean gestational age at the time of fetal death was 30 +/- 4 weeks. During index pregnancies, we observed 2 miscarriage, 9 liveborns (6 of appropriated gestational weight, 3 SGA) and a mean gestational age of 35 +/- 3 weeks. The mean decrease in fetal weight from the 50th percentile in previous pregnancies was 44%, and with treatment this was reduced to 12%. All these differences were statistically significant. We conclude that prednisone and heparin treatment can improve reproductive prognosis in fertile patients with LAC.

Abortion, Habitual↗
PubMed1989

Foetal pulmonary maturation in pregnancies complicated by diabetes and Rh immunization.

In pregnancies complicated by diabetes, foetal lung maturation depends on a good control of maternal blood glucose values. In poorly controlled maternal diabetes, foetal hyperinsulinaemia may cause a delay in pulmonary maturation. There was no single case of respiratory distress syndrome (RDS) in 112 pregnant class B-F diabetic patients that we treated with high doses of insulin. Furthermore, in a controlled randomized trial of diet versus insulin treatment in class A diabetes we found no differences in perinatal mortality in patients with adequate metabolic control. In pregnancies complicated by Rh isoimmunization, determination of phosphatidylglycerol in amniotic fluid is a more reliable marker of foetal lung maturity than is the lecithin/sphingomyelin ratio. The marked decrease in perinatal mortality due to Rh incompatibility observed in recent years depends on several factors including administration of corticosteroids to the mother to prevent RDS, irrespective of whether amniotic fluid parameters indicate foetal lung maturity.

Blood Glucose↗
PubMed1989

Prenatal diagnosis and management of congenital heart disease.

Thirty-two fetuses were diagnosed as having congenital heart disease (CHD). The major indications for level II echocardiography other than suspected cardiac abnormalities were fetal malformations, nonimmune hydrops and cardiac arrhythmia. Only three patients had a previous history of fetal CHD. No false-abnormal diagnosis of severe CHD was made. Aortic arch anomalies represented the major diagnostic problem among the six correct but incomplete diagnoses. Sixty-one percent of the fetuses were growth retarded, thus confirming the severity of their CHD. Chromosomal anomalies and extracardiac malformations were associated in 19% and 44% of the fetuses, respectively. Obstetric management and fetal prognosis in cases of extracardiac malformations were greatly influenced by the diagnosis of CHD. The poorest perinatal outcome was associated with heart failure. The only intrauterine deaths occurred in that group, and only one neonate survived. The outcome was more favorable in neonates without other malformations or heart failure. Four of ten (40%) of those neonates survived, while the overall perinatal survival rate was 24%.

Chromosome Aberrations↗
PubMed1988

The correlation of biochemical monitoring versus umbilical flow velocity measurements of the human fetus.

The pulsatility index of the fetal umbilical arteries was evaluated in 14 high-risk pregnant patients delivered by cesarean section between 30 and 35 weeks of gestation. Transabdominal cord sampling by ultrasonic guidance was performed on 10 of these patients. Umbilical arterial and venous blood was obtained in all patients from the doubly clamped cord at the time of cesarean section. The blood samples were analyzed for respiratory gases, acid-base balance, and lactate concentrations. A significant relationship was found between the pulsatility index and pH, PCO2, and lactate concentrations measured on umbilical venous blood sampled in utero. The pulsatility index also correlated with the same variables measured on venous and arterial blood sampled at cesarean section. Umbilical venous blood obtained transabdominally had a significantly higher oxygen content than blood obtained at cesarean section. No significant correlation was found between umbilical venous oxygen content obtained at transabdominal cord sampling and the pulsatility index. At a pulsatility index greater than 1.5, lactate concentrations in umbilical venous blood increased sharply. There would appear to be a curvilinear relationship between umbilical blood flow and these indices of fetal oxygenation, such that moderate increases in pulsatility index were not associated with a significant increase in fetal lactate concentrations.

Acid-Base Equilibrium↗