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Biomedical subjects

K Marsál

Publications and source records attributed to K Marsál.

At least 55 records · Page 3Linked to original sources
PubMed1996

Ductus venosus velocimetry in high-risk pregnancies.

OBJECTIVE: Umbilical venous (UV) blood velocity pulsations have been considered as a late sign of fetal hypoxemia in high-risk pregnancies. Ductus venosus (DV) functions as a pressure filter as it conducts umbilical blood into the inferior vena cava of the fetus. The aim of this paper was to evaluate whether DV Doppler velocimetry might give earlier indication of fetal hypoxemia than does UV blood velocity. DESIGN: Recording of DV blood velocity in complicated pregnancies referred for umbilical artery (UA) velocimetry as one aspect of fetal surveillance. METHOD: DV and UV blood velocities were recorded serially by Doppler ultrasound in 87 high-risk pregnancies and the results of the last examination before delivery were correlated to perinatal outcome. RESULTS: Abnormal DV blood velocity waveforms recorded in 26 pregnancies were not correlated to perinatal outcome, except for low Apgar score at one minute of life. Abnormal UV blood velocity pulsations in the cord were recorded in 11 fetuses, of which only 6 had abnormal DV velocimetry. UV pulsations were related to adverse perinatal outcome and all these fetuses had abnormal UA velocimetry. CONCLUSION: Abnormal DV blood velocity is more frequently recorded in high-risk pregnancies than UV pulsations, but appears to be a poor indicator of adverse perinatal outcome.

Blood Flow Velocity↗
PubMed1996

Fetal and uteroplacental circulatory changes in pregnancies proceeding beyond 43 weeks.

BACKGROUND: Practically all reference curves for Doppler blood flow variables in pregnancy end at 40 weeks. OBJECTIVE: To study fetal and uteroplacental circulatory changes in pregnancies proceeding beyond 43 weeks. STUDY DESIGN: Longitudinal comparisons from 42 to 43 weeks and comparisons with controls at term. MATERIAL: Thirty-four women delivered after 43 completed weeks (301 days) and a control group of 32 women delivered at 271 days of gestation. METHODS: From 42 weeks (294 days), serial Doppler blood flow measurements were performed in the fetal descending aorta, umbilical vessels, and maternal uterine artery. STATISTICAL METHODS: Student's unpaired t-test, Mann-Whitney U-test, and Fisher's exact test for comparison of groups; Student's paired t-test and Wilcoxon's signed-rank matched-pairs test for longitudinal data; simple linear regression analysis for comparison of variables. A two-tailed P-value of < 0.05 was considered statistically significant. RESULTS: From 42 to 43 weeks, the mean flow velocity decreased significantly in the fetal aorta and increased significantly in the umbilical vein. Compared to controls, the velocity and volume flow in the aorta and the umbilical artery flow resistance were significantly lower at 43 weeks. No significant change in uterine artery flow resistance was found. CONCLUSIONS: The changes in Doppler blood flow variables were all in accordance with physiological circulatory alterations enhancing continued fetal growth until the late post-term period. There were no signs of any general circulatory deterioration. Doppler velocimetry reference values at term may not be appropriate for evaluation of very advanced gestations.

Adult↗
PubMed1996

Uterine and umbilical circulation during the oxytocin challenge test.

Our objective was to study uterine and umbilical artery flow resistance during the oxytocin challenge test (OCT). The study population was 21 women with suspected placental insufficiency; one woman was excluded because of a positive OCT with reactive fetal heart rate pattern. We carried out simultaneous electronic fetal heart rate monitoring and Doppler velocimetry of uterine and umbilical artery flow during the OCT. The uterine artery flow resistance increased significantly during contractions in both OCT-positive (n = 5) and OCT-negative (n = 15) cases compared with basal values, but the increase was significantly higher in positive cases. The umbilical artery flow resistance increased significantly during contractions in OCT-positive cases, but was almost unchanged in negative cases. During uterine inactivity, there were no differences between the groups for any vessel. This study showed that fetal heart rate decelerations during the OCT are associated with rapid and exaggerated increases of vascular resistance in both uterine and umbilical arteries. The causal relationship is unknown, but the findings indicate pathophysiological mechanisms revealed only during uterine contractions.

Blood Flow Velocity↗
PubMed1996

Intrauterine growth curves based on ultrasonically estimated foetal weights.

Available standard intrauterine growth curves based on birthweights underestimate foetal growth in preterm period. New growth curves are presented based on data from four Scandinavian centres for 759 ultrasonically estimated foetal weights in 86 uncomplicated pregnancies. Mean weight of boys exceeded that of girls by 2-3%. A uniform SD value of 12% of the mean weight was adopted for the standard curves as the true SD varied non-systematically between 9.1 and 12.4%. Applied to an unselected population of 8663 singleton births, before 210 days of gestation, 32% of birthweights were classified as small-for-gestational age (SGA; i.e. below mean - 2 SD); the corresponding figures were 11.1% for gestational ages between 210 and 258 days, and 2.6% for ages of 259 days or longer. The new growth curves reveal better the true distribution of SGA foetuses and neonates, and are suggested for use in perinatological practice.

Anthropometry↗
PubMed1996

Fetal pulse oximetry. A methodogical study.

BACKGROUND: During recent years fetal pulse oximetry has been under development for use in monitoring fetal oxygenation during labor. In a methodological study we have tested the practical applicability of one type of sensor (FS-10 Oxisensor, Nellcor). Both obstetricians and midwives took active part in sensor placement. The readings of fetal arterial oxygen saturation (SpO2) were not taken into account when managing the patients. METHODS: Oxygenation was monitored during labor in 96 singleton pregnancies. Mean SpO2 levels were calculated when cervical dilatation was 4-7 cm and 8-10 cm, and in the second stage of labor. Student's t-test was used for paired comparisons. A p-value<0.05 was considered significant. RESULTS: Of the 96 oxisensors, 91 (95%) were successfully placed. One mother felt pain which disappeared when the sensor was removed. Two of the newborns manifested an impression mark caused by the sensor, which disappeared completely within a day. No infection or increased bleeding was noted. The mean recording time was 134 minutes. SpO2-values were obtainable during 69% of the recording time. A significant fall of mean SpO2 occurred between the first and second stages of labor. CONCLUSIONS: The method seems to be harmless for mother and child, and allows SpO2-values to be obtained during two thirds of the recording period. Further research is needed to evaluate the possible clinical value of the method.

Adolescent↗
PubMed1995

Reduced contractile effect of endothelin-1 and noradrenalin in human umbilical artery from pregnancies with abnormal umbilical artery flow velocity waveforms.

This study on the human umbilical artery was undertaken in order to elucidate possible correlations between changes in response to vasoactive substances in vitro and abnormal umbilical artery flow velocity waveforms in vivo associated with preeclampsia and intrauterine growth retardation. The vascular reactivity to endothelin-1, noradrenalin, serotonin, the thromboxane A2 analogue U46619, substance P and prostacyclin was determined in umbilical artery segments from 13 normal pregnancies and 29 pregnancies complicated with preeclampsia and/or intrauterine growth retardation with normal or abnormal umbilical flow velocity waveforms. The contractile effect in vitro of endothelin-1 and noradrenalin was reduced in segments from pregnancies complicated by abnormal umbilical flow velocity waveforms in vivo. No differences were detected in the contractile effect of serotonin and U46619, or in the relaxatory effect of substance P and prostacyclin. In conclusion, endothelin-1- and noradrenalin-related mechanisms could be involved in the abnormal umbilical flow velocity waveforms associated with preeclampsia and intrauterine growth retardation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1995

Effect of a prostaglandin E1 analogue (gemeprost) on uterine and luteal circulation in normal first trimester pregnancies. A Doppler velocimetry study.

OBJECTIVE: To evaluate the effects of gemeprost on utero-placental and luteal circulation and on the embryo/fetus in normal first trimester pregnancies. STUDY DESIGN: Sixty-seven women with a normal first trimester pregnancy requesting termination of pregnancy for psychosocial reasons were randomly allocated to pre-operative treatment with vaginal suppositories containing placebo or gemeprost. The women underwent transvaginal color and spectral Doppler ultrasound examination before the application of the suppository, 4 h after the application of the suppository but before the abortion, and on the seventh post-operative day. Blood flow velocities in the uterine and subchorionic arteries, the intrachorionic area and arteries in the wall of the corpus luteum and the embryonic/fetal heart rate were measured. RESULTS: The median value for pulsatility index (PI) in the dominant uterine artery was 2.4 before treatment with gemeprost and 8.5 4 h after treatment (P = 0.0006); the corresponding values for time-averaged maximum velocity (TAMXV) being 27 cm/s and 10 cm/s (P = 0.0006). Four (14%) of 28 embryos/fetuses in the gemeprost group were dead 4 h after treatment with gemeprost and the median heart rate of those still alive was significantly lower than before treatment (130 vs. 163 bpm; P = 0.003). In the placebo group, the results for the uterine arteries and the embryonic/fetal heart rate did not differ significantly between the first and second ultrasound examinations. The median values for PI and TAMXV in the arteries of the corpus luteum wall at the first ultrasound examination were 0.71 and 18 cm/s, respectively, in the placebo group and 0.71 and 20 cm/s, respectively, in the gemeprost group. These values remained almost unchanged at the second and third ultrasound examinations in both groups. CONCLUSION: Gemeprost has profound effects on utero-placental circulation in the first trimester and can induce embryonic/fetal bradycardia and sometimes embryonic/fetal demise. It has no unequivocal effect on luteal circulation.

Abortion, Induced↗
PubMed1995

Lack of association between Doppler velocimetry and synthesis of prostacyclin and thromboxane in umbilical cord vessels from growth retarded fetuses.

BACKGROUND: The aim of this study was to investigate the possible association between Doppler velocimetry and synthesis of prostacyclin (PGI2) and thromboxane A2 (TxA2) in umbilical cord vessels. The hypothesis was that an altered balance between PGI2 and TxA2 production is associated with a change of artery flow resistance. METHODS: 17 cases with a suspicion of intrauterine growth retardation and 21 normal pregnancies were studied. The umbilical artery pulsatility index (PI) and venous mean velocity were recorded in vivo by Doppler velocimetry. Cord vessel prostanoid synthesis was determined in vitro. The Mann-Whitney U test and simple linear regression were used for statistical analyses. RESULTS: The umbilical vessel synthesis of both PGI2 and TxA2 was in general lower in small-for-gestational age (SGA) cases (n = 10) compared to appropriate-for-gestational age (AGA) (n = 28). In the vein, the PGI2/TxA2 ratio was significantly lower in SGA cases. No certain correlations were found between umbilical artery PI and venous velocity, respectively, and PGI2 or TxA2, or their ratio. CONCLUSION: The prostanoid synthesis was in general lower in SGA cases, resulting in a significantly lower PGI2/TxA2 ratio in the umbilical vein. This indicates that fetal growth retardation might be associated with a disturbed endothelial function in this vessel. The synthesis of PGI2 and TxA2 in the juxtaplacental umbilical cord vessels was not correlated to the umbilical artery PI or venous flow velocity. It is possible that an altered release of prostanoids in the placental vasculature and tissue accounts for the rise of umbilical artery flow resistance instead.

6-Ketoprostaglandin F1 alpha↗
PubMed1995

Umbilical artery velocimetry may influence clinical interpretation of intrapartum cardiotocograms.

BACKGROUND: In a previous prospective randomised trial on pregnancies complicated by small-for-gestational-age fetuses fewer operative deliveries for fetal distress were found after antenatal surveillance with umbilical artery Doppler velocimetry (Doppler group) than after surveillance with cardiotocography (CTG group). Despite that, the neonatal outcome was similar in both groups. This raised the question whether the knowledge of the antenatal Doppler results had influenced the obstetric management of labor. METHODS: In this retrospective study 242 intrapartum cardiotocogram tracings, obtained from the above mentioned prospective trial, were re-interpreted by an expert without knowledge of the results in the original study. The re-interpretation was then compared to the original interpretation. RESULTS: The expert interpreted 18 intrapartum tracings in the Doppler group and 18 in the CTG group as abnormal, whereas the clinicians interpreted only 8 tracings as abnormal in the Doppler group and 18 tracings in the CTG group. CONCLUSIONS: The results of this retrospective study lend support to our hypothesis that the obstetricians in clinical practice are influenced by the knowledge of a normal umbilical Doppler velocimetry when interpreting an intrapartum CTG. This finding may partly explain why there were fewer emergency cesarean sections for fetal distress in the Doppler group than in the CTG group in the original prospective study.

Blood Flow Velocity↗
PubMed1995

Transvaginal Doppler examination for the differential diagnosis of solid pelvic tumors.

To evaluate the ability of transvaginal Doppler examination to discriminate between different types of solid pelvic tumors, 55 women scheduled for laparotomy because of a solid pelvic mass underwent transvaginal sonographic examination, including color and spectral Doppler techniques. Arteries in the wall and core of each mass were examined. The histological diagnoses were as follows: uterine myoma (n = 28), malignant ovarian tumor (n = 19), and benign ovarian tumor (n = 8). Pulsatility index values tended to be highest in the malignant ovarian tumors, albeit with considerable overlap with respect to the other tumor types. The respective median pulsatility index values for arteries in the wall and core of the malignant ovarian tumors were 0.93 and 0.87, versus 0.65 and 0.51 in the benign ovarian tumors and 0.80 and 0.67 in the myomas. Time-averaged maximum velocity did not differ significantly among the three types of tumor. We conclude that Doppler measurement of blood flow velocity in tumor arteries does not add substantial information to the differential diagnosis between myomas and benign or malignant solid ovarian tumors.

Adult↗
PubMed1994

Endometrial thickness and Doppler velocimetry of the uterine arteries as discriminators of endometrial status in women with postmenopausal bleeding: a comparative study.

OBJECTIVE: Our purpose was to compare the ability of transvaginal Doppler ultrasonographic examination with that of gray-scale ultrasonographic examination to discriminate between benign and malignant and between normal and pathologic endometrium in women with postmenopausal bleeding. STUDY DESIGN: One hundred thirty-eight consecutive women scheduled for curettage because of postmenopausal bleeding underwent transvaginal ultrasonography, including color and spectral Doppler techniques, within 8 days preceding the operation. The thickness of the endometrium was measured. Doppler signals of the maximum blood flow velocity obtained from the two main uterine arteries and subendometrial and intraendometrial arteries were evaluated for pulsatility index and time-averaged maximum velocity. The results of the examinations were compared with the histologic diagnosis of the curettage specimen. RESULTS: Receiver-operator characteristic curves showed endometrial thickness to be a better discriminator between normal and pathologic and between benign and malignant endometrium than any Doppler variable, 14 mm being the optimal threshold value for differentiating between benign and malignant endometrium (sensitivity 88%, specificity 81%). CONCLUSION: Measurement of endometrial thickness with transvaginal ultrasonography is a better method for discriminating between benign and malignant or normal and pathologic endometrium than is Doppler velocimetry of the uterine arteries.

Aged↗
PubMed1994

Placental histology and fetal blood flow in intrauterine growth retardation.

OBJECTIVE: To define the histological lesions in the placenta associated with abnormal blood flow findings and to evaluate their possible clinical significance. DESIGN: A prospective blind study. SETTING: A clinical study at a teaching hospital, Malmö General Hospital, University of Lund, Sweden, morphological studies of placentas being performed at the Institute of Pathology, University of Lausanne, Switzerland. MATERIAL: Thirty-seven pregnancies where intrauterine growth retardation (IUGR) was suspected. METHODS: Blood velocimetry of the fetal descending aorta, umbilical artery and vein, and the maternal arcuate artery, using 2.5 MHz pulsed wave Doppler ultrasound. Histological examination of at least five random samples from each placenta. MAIN OUTCOME MEASURES: Frequency of small-for-gestational age (SGA) newborns (birth weight < or = mean -2 s.d.) and of operative delivery for fatal distress. RESULTS: Only the presence of placental infarction was significantly associated with IUGR and with intrauterine findings of abnormal blood velocity in the fetal descending aorta and umbilical artery. CONCLUSION: Placental infarction would seem to be a valuable morphological marker of uteroplacental vascular disease related to IUGR and impaired fetal and umbilical blood flow.

Adolescent↗
PubMed1994

Rational use of Doppler ultrasound in perinatal medicine.

Doppler ultrasound velocimetry of uteroplacental, umbilical and fetal vessels provides the clinician with important information on the hemodynamics of respective vascular area. Gestational age-related reference values have been established for maternal uterine and arcuate artery, umbilical artery, fetal descending aorta, and fetal cerebral, renal and femoral arteries. Recently, velocimetry of the fetal central venous system gained increasing attention. In growth-retarded fetuses and fetuses developing intrauterine distress, the umbilical artery blood velocity waveform changes in a typical way: the diastolic velocity of the waveform decreases and eventually disappears. The absent or reverse end-diastolic flow (ARED flow) is associated with high risk of intrauterine demise and adverse perinatal outcome. Applied as a screening test in an unselected pregnant population, umbilical artery velocimetry has not been found useful. In a preselected population of high-risk pregnancies, especially pregnancies with SGA fetuses, the method has a high predictive value with regard to diagnosing fetal compromise and can be used for monitoring fetal health. A meta-analysis of randomized clinical trials showed that including Doppler velocimetry in the management of high-risk pregnancies lowers the perinatal mortality. Follow-up studies, few published so far, showed an association between the abnormal intrauterine umbilical and/or fetal blood flow and subsequent postnatal neurodevelopmental impairment. Doppler velocimetry of umbilical artery applied in management of high risk pregnancies improves the perinatal outcome and can thus be considered a clinical method of fetal surveillance.

Blood Flow Velocity↗
PubMed1994

Role of Doppler sonography in fetal/maternal medicine.

Doppler velocimetry of umbilical, fetal, and uteroplacental vessels provides important information on fetal and uterine hemodynamics and has therefore become one of the most dynamic areas of perinatal research. Examinations of umbilical artery velocity waveforms have gained recognition as a valuable clinical method of fetal surveillance in risk pregnancies. Pathological Doppler findings, especially the finding of absent or reverse end-diastolic (ARED) flow velocity, are associated with fetal hypoxia and adverse outcome of pregnancy. The first follow-up studies indicate that abnormal Doppler findings are associated with impaired postnatal neurological development. Velocimetry of the fetal middle cerebral artery provides important information on redistribution of fetal blood flow in hypoxia; its place in clinics remains to be established. Similarly, more studies are needed to evaluate the use of Doppler velocimetry in labor. Possibly, the Doppler method may facilitate the interpretation of equivocal cardiotocography (CTG) tracings. New evidence has been collected on the correlation between hemodynamic findings and the morphology of the placenta and the placental bed. One of the very important applications of Doppler velocimetry is the evaluation of pharmacological effects on fetal circulation of drugs used for treatment in pregnancy and labor.

Cardiotocography↗
PubMed1993

Blood flow velocity in the uterine and ovarian arteries during the normal menstrual cycle.

Twelve healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on cycle days 4 and 8 and daily from cycle day 12 until follicular rupture, then days + 1, +2, +5, +7 and +12 after follicular rupture. The uterine and subendometrial arteries, arteries in the ovarian stroma and hilum, in the wall of the largest follicle of each ovary, and in the wall of the corpus luteum were examined. The pulsatility index and the time-averaged maximum velocity were calculated. In the uterine arteries the pulsatility index was highest on day + 2, after which it decreased successively to its lowest value, whereas the time-averaged maximum velocity reached its highest value on day + 12. Similar changes were observed in the subendometrial arteries. In the non-dominant ovary, neither the pulsatility index nor the time-averaged maximum velocity manifested any consistent changes during the cycle. In the dominant ovary, the time-averaged maximum velocity increased and the pulsatility index decreased after follicular rupture, being significantly higher and lower, respectively, in the luteal than in the follicular phase. These changes were seen in the ovarian hilum, stroma and follicular wall, but were most obvious in the wall of the dominant follicle and of the corpus luteum. We conclude that the blood circulation in the uterus and in the dominant ovary changes considerably during the menstrual cycle, whereas that in the non-dominant ovary shows no unequivocal changes.

Journal Article↗
PubMed1993

Clinical evaluation of the fetus and neonate. Relation between intra-partum cardiotocography, Apgar score, cord blood acid-base status and neonatal morbidity.

The relation between intra-partum cardiotocography (CTG), cord blood acid-base status, Apgar score and neonatal morbidity was studied in 1228 consecutively live-born babies and in a subgroup of 200 babies (148 babies with a 1 min Apgar score < or = 8 and 52 randomly selected babies with a 1 min Apgar score > or = 9). The scores for the individual components of the 1 min Apgar score were strongly associated with each other, whereas the scores for the individual components of the 5 min Apgar score were less strongly associated. At 1 min the scores for muscle tone, reflex irritability and respiration but not the scores for heart rate and skin colour were associated with arterial and venous cord blood pH (low scores being associated with low pH). Out of the individual components of the Apgar score, heart rate and reflex irritability at 1 min were the best discriminators between "healthy or relatively healthy" and "severely ill" babies. Intrapartum CTG, total Apgar score and cord blood acid-base status were only weakly related. Venous cord blood pH was the best predictor of the 1 min Apgar score. Intra-partum CTG (silent pattern), 5 min Apgar score and venous cord blood pH were the best predictors of severe neonatal morbidity.

Acid-Base Equilibrium↗
PubMed1993

A high uterine artery pulsatility index reflects a defective development of placental bed spiral arteries in pregnancies complicated by hypertension and fetal growth retardation.

INTRODUCTION: The development of PIH is associated with a defective trophoblast invasion and conversion of spiral arteries into low-resistance uteroplacental arteries. Hypertension may then be a compensatory response to a defective uteroplacental perfusion. Similar mechanisms may operate in IUGR. AIM: To compare uterine artery Doppler blood flow measurements with placental bed histology. The hypothesis was that placental bed vessel pathology plays a role for a raised flow resistance. MATERIALS AND METHODS: After blood flow measurements, a placental bed biopsy was taken at CS in 26 complicated (study group) and 29 uncomplicated pregnancies (control group). RESULTS: The uterine artery PI was significantly more often abnormally high in the study group compared with the control group, and also in hypertensive pregnancies compared with normotensive IUGR pregnancies. Physiological vessel changes were found in all controls but were absent in 76% of study cases. Physiological changes were significantly more often absent in SGA than in AGA newborns. Absence of physiological changes were significantly more often found in cases with an abnormally high PI. DISCUSSION: The results link together circulatory and structural pathophysiological changes of the uteroplacental unit. A defective physiological conversion of the spiral arteries was associated with an increased uterine flow resistance. CONCLUSION: This study gave further support for the existence of a triad of defective placental bed vessel maturation, increased uteroplacental flow resistance, and hypertension.

Adolescent↗