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Biomedical subjects

Z Weiner

Publications and source records attributed to Z Weiner.

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

Central and peripheral haemodynamic changes in post-term fetuses: correlation with oligohydramnios and abnormal fetal heart rate pattern.

OBJECTIVE: To assess the hypothesis that the occurrence of oligohydramnios and abnormal fetal heart rate (FHR) pattern in post-term fetuses is associated with impaired fetal cardiac function. DESIGN: A cross sectional study was performed on post-term and term fetuses. Fetal tests included a computerised analysis of the FHR, a biophysical profile and Doppler studies of the abdominal aorta, umbilical artery, middle cerebral artery and the fetal heart. Pulsatility index (PI) was calculated from the abdominal aorta, umbilical and middle cerebral artery flow velocity waveforms. Peak velocity, velocity time integral (VTI), E:A ratio, and heart rate (HR) were calculated from the flow velocity waveforms obtained from the aortic and pulmonic outflow, and from the mitral and tricuspid valves. SETTING: Maternal fetal laboratory, Department of Obstetrics. SAMPLE: One hundred and twenty post-term and 42 term fetuses. RESULTS: Only the tricuspid E:A ratio was significantly higher (P < 0.05) in post-term fetuses with a normal amniotic fluid index compared with term fetuses. Post-term fetuses with an abnormal amniotic fluid index had a significantly lower aortic peak velocity (P < 0.01), aortic VTI x HR (P < 0.01), and mitral VTI x HR (P < 0.05) compared with post-term fetuses with a normal amniotic fluid index or compared with term fetuses. Post-term fetuses with reduced FHR variation had a significantly lower aortic peak velocity (P < 0.01), pulmonic peak velocity (P < 0.05), aortic VTI x HR (P < 0.01), pulmonic VTI x HR (P < 0.05) and a significantly lower mitral VTI x HR (P < 0.05) when compared with post-term fetuses with normal FHR variation. Similar results were obtained in comparing fetuses with normal and adverse perinatal outcome. CONCLUSION: The occurrence of oligohydramnios and abnormal FHR pattern in post-term fetuses appears to be associated with impaired fetal cardiac function. This finding should allow further investigations of post-term fetuses.

Adult↗
PubMed1996

Surveillance of growth-retarded fetuses with computerized fetal heart rate monitoring combined with Doppler velocimetry of the umbilical and uterine arteries.

OBJECTIVE: To define guidelines for surveillance of growth-retarded fetuses with a computerized fetal heart rate (FHR) monitor and Doppler device. STUDY DESIGN: Eighty-one growth-retarded fetuses with birth weights < 10th percentile and lacking major anomalies were studied. One hundred ninety-two tests (one to six per patient), including computerized FHR monitoring and Doppler studies of the umbilical and uterine arteries, were performed. The relationship between Doppler velocimetry or FHR variation and fetal outcome was examined. RESULTS: Fetuses with an abnormal FHR variation or abnormal Doppler velocimetry had a significantly higher rate of cesarean deliveries for fetal distress and a higher number of admissions to the neonatal intensive care unit (NICU) as compared with fetuses with normal results on both tests. The best distinction was noted when the growth-retarded fetuses were partitioned into four analytic groups based on the presence of normal or abnormal FHR variation or Doppler velocimetry. The group with the poorest results was composed of fetuses with abnormal umbilical flow velocity and reduced FHR variation. These fetuses had significantly lower birth weights (1,250 g) and significantly higher rates of cesarean deliveries for fetal distress (92%) and admission to the NICU (100%). Thirty percent of these fetuses died. CONCLUSION: Fetal surveillance with Doppler and computerized FHR monitoring allows better understanding of the management of fetuses that are small for gestational age.

Adult↗
PubMed1996

Computerized analysis of fetal heart rate changes after antepartum external cephalic version.

OBJECTIVE: To assess the fetal heart rate (FHR) changes following external cephalic version using a computerized FHR monitor. STUDY DESIGN: We performed 116 external cephalic versions on 106 pregnant women at 36-40 weeks' gestation. Tocolysis (magnesium sulfate) was given to 39 patients (34%). Computerized FHR monitoring was performed for 20-30 minutes before and for 20-30 minutes after the procedure. In addition, we analyzed the results of the FHR tracing obtained during the first 10 minutes following the procedure. RESULTS: External cephalic version was successful in 40% of the patients. In the group of patients who were not treated with magnesium sulfate, FHR variation and the number of accelerations per 10 minutes were significantly reduced during the first 10 minutes following the procedure as compared with those factors on the FHR tracings obtained before or 20-30 minutes following the procedure (P < .05). In the group of patients who were treated with magnesium sulfate, FHR variation and the number of accelerations per 10 minutes were significantly reduced before and 10 minutes after the procedure as compared with the FHR tracings obtained 20-30 minutes following the procedure (P < .05). In both groups the basal FHR was significantly lower during the first 20-30 minutes following the procedure (P < .05). FHR decelerations were observed following the procedure in only two patients. None of the 106 fetuses had a low Apgar score or were admitted to the neonatal intensive care unit. CONCLUSION: External cephalic version appears to be safe for the mother and fetus, although transient FHR changes may occur following the procedure.

Adult↗
PubMed1995

The advantages of using triple-marker screening for chromosomal abnormalities.

OBJECTIVE: Our purpose was to assess the utility of triple-marker serum screening for chromosomal abnormalities. STUDY DESIGN: Our laboratory received 10,605 samples that were between 15 and 22 weeks' gestation for maternal serum screening of chromosomal abnormalities. Triple-marker maternal serum screening consisted of alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol in conjunction with maternal age. Women > or = 35 years old were first offered amniocentesis. If they refused amniocentesis, they were offered the screening test. A second-trimester risk for trisomy 21 > or = 1:270 was considered screen positive. Patients were screen positive for trisomy 18 if all three markers were low: alpha-fetoprotein < or = 0.75 multiples of the median, unconjugated estriol < or = 0.60 multiples of the median, and human chorionic gonadotropin < or = 0.55 multiples of the median. RESULTS: The initial screen-positive rate was 8.3% (880 women); amniocentesis was offered to 766 (7.2%). Twelve of 16 ascertained cases of trisomy 21 (75%), two of three cases of trisomy 18 (67%), five cases of 45,X karyotype, and one case each of 45,X/46,XX, 47,XXY, 47,XYY, 46,XX,ins(2)(q21p13p15)mat, and 69,XXX karyotypes were identified in the screen-positive patients. All four known cases of trisomy 21 in the 886 women > or = 35 years old who were screened were detected, with a 21% false-positive rate. Omitting unconjugated estriol from our screening program would have resulted in detecting nine of 16 trisomy 21 and six of 12 other chromosomal abnormalities. The false-positive rate would have remained the same. CONCLUSION: In our sample cohort addition of unconjugated estriol to the screening program resulted in an increased detection rate of chromosomal abnormalities with no change in the false-positive rate. Considering the advancement in screening for chromosomal abnormalities, maternal age alone as an indication for amniocentesis should be reevaluated.

Adolescent↗
PubMed1995

Triple marker (alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin) versus alpha-fetoprotein plus free-beta subunit in second-trimester maternal serum screening for fetal Down syndrome: a prospective comparison study.

OBJECTIVE: Our purpose was to compare the efficacy of triple-marker screening (alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin) with alpha-fetoprotein plus free beta-human chorionic gonadotropin. STUDY DESIGN: Free beta-human chorionic gonadotropin was concurrently assayed in 2349 maternal serum samples. Trivariate and bivariate algorithms were used to calculate the risk for fetal Down syndrome by the two protocols. Free beta-human chorionic gonadotropin from 12 cases of fetal Down syndrome previously screened with the triple marker was retrospectively assayed. RESULTS: Mean maternal age of our study was 29.8 years (range 14 to 51 years). The initial screen-positive rate with the triple marker was 8.0% compared with 12.8% for alpha-fetoprotein plus free beta-human chorionic gonadotropin. All three cases of fetal Down syndrome ascertained in our prospective study were detected by the triple marker; in contrast, one of three was detected by alpha-fetoprotein plus free beta-human chorionic gonadotropin. By adding 12 additional cases of fetal Down syndrome, 12 of 15 (80%) were screen positive with triple marker and nine of 15 (60%) were screen positive with alpha-fetoprotein plus free beta-human chorionic gonadotropin. CONCLUSION: The detection rate of fetal Down syndrome was greater by use of a triple marker screen than when using alpha-fetoprotein plus free beta-human chorionic gonadotropin. Our data do not support the claims of other studies that suggest that alpha-fetoprotein plus free beta-human chorionic gonadotropin is superior to triple markers.

Adolescent↗
PubMed1995

Ultrasound in twin pregnancy.

This review evaluates the role of ultrasound in twin gestation. Ultrasound is essential in the diagnosis and management of perinatal complications common in twins, including fetal anomalies, conjoined twins, acardiac twinning, fetal demise, prematurity, intrauterine growth retardation, and twin-to-twin transfusion. Indications for first-trimester scanning are reviewed, as well as its use in determining type of placentation, chorionicity, and amnionicity. The focus of this article will be the use of ultrasound and Doppler velocimetry in the evaluation of fetal growth and subsequent management of intrauterine growth retardation in twins, as well as the value of real-time ultrasound and Doppler evaluation in the diagnosis of discordant growth and twin-to-twin transfusion syndrome.

Computer Systems↗
PubMed1994

Computerized analysis of fetal heart rate variation in postterm pregnancy: prediction of intrapartum fetal distress and fetal acidosis.

OBJECTIVE: Our purpose was to evaluate whether computerized analysis of fetal heart rate variation may improve fetal surveillance in postterm pregnancy. STUDY DESIGN: Three hundred thirty-seven pregnant women who were delivered after 41 weeks' gestation and who had 610 antenatal tests were included in this study. Fetal tests included a nonstress test with a computerized analysis of the fetal heart rate, Doppler examination of the umbilical artery, and a biophysical profile, performed every 2 to 4 days. Induction of labor was performed when the fetal heart rate variation was reduced (< 30 msec), when fetal heart rate decelerations appeared, or when the amniotic fluid index was < or = 5. The results of the fetal surveillance tests were compared with the results of the intrapartum fetal heart rate monitoring and with the metabolic status of the babies at delivery. Sensitivity and specificity of the various tests in predicting intrapartum fetal distress and acidosis at delivery were described by means of the receiver-operator characteristic curve. RESULTS: Ten of 12 fetuses with reduced fetal heart rate variation had a trial of labor. Nine of these 10 fetuses had fetal distress during labor. Seven of the 12 fetuses with reduced fetal heart rate variation were acidotic at delivery (umbilical artery pH < 7.2). Overall, there were 10 acidotic fetuses at delivery in the study group. Only two of them had an umbilical systolic/diastolic ratio > 95th percentile, three had an amniotic fluid index < or = 5, and five had fetal heart rate decelerations before labor. Fetuses who demonstrated an abnormal intrapartum fetal heart rate tracing or who were acidotic at delivery had a significantly higher rate of reduced fetal heart rate variation or decelerations before labor. The largest area under the receiver-operator curve curve for predicting fetal acidosis at delivery or fetal distress during labor was achieved by means of computerized analysis of fetal heart rate variation. CONCLUSION: A computerized numeric analysis of fetal heart rate variation may improve fetal surveillance in postterm pregnancy.

Acidosis↗
PubMed1994

Central and peripheral hemodynamic changes in fetuses with absent end-diastolic velocity in umbilical artery: correlation with computerized fetal heart rate pattern.

OBJECTIVES: Our purpose was to study hemodynamic changes in peripheral and central blood vessels and to correlate these changes with the computerized fetal heart rate pattern in fetuses with absent end-diastolic velocity in the umbilical artery. STUDY DESIGN: Doppler studies of the umbilical artery, the middle cerebral artery, and aortic and pulmonic outflow, together with computerized fetal heart rate monitoring, were performed every 2 to 4 days until delivery in 13 fetuses with absent end-diastolic velocity in the umbilical artery. The pulsatility index was calculated from the flow velocity waveforms obtained from the umbilical and middle cerebral arteries. The velocity time integral (an index of cardiac output) and the heart rate were calculated from the flow velocity waveforms obtained from the aortic and pulmonic outflow. RESULTS: Two fetuses were delivered immediately after the first examination because of repetitive fetal heart rate decelerations. One fetus was excluded from the study because of major malformations. Ten had three to eight tests each. Six had a biphasic change of the middle cerebral artery, which consisted of a decrease (p < 0.001) followed by an increase in the pulsatility index (p < 0.05). When the middle cerebral artery lost its vasodilation, there was an increase in the middle cerebral artery/umbilical artery pulsatility index ratio (p < 0.05). Left cardiac output decreased (p < 0.05), resulting in an increase in the pulmonary/aortic velocity time integral x heart rate ratio (p < 0.05). Reduced fetal heart rate variation (< 30 msec) developed in all six fetuses, and they were delivered because of repetitive fetal heart rate decelerations. Four fetuses with only a decrease in the middle cerebral artery pulsatility index did not have reduced fetal heart rate variation or decelerations, the aortic velocity time integral x heart rate didn't decrease, and the pulmonic/aortic velocity time integral x heart rate ratio didn't increase. These fetuses were delivered for reasons other than fetal distress. The middle cerebral artery pulsatility index correlated with the aortic velocity time integral x heart rate (r = -0.53, p < 0.0001), and the middle cerebral artery/umbilical artery pulsatility index correlated with the pulmonic/aortic velocity time integral x heart rate (r = 0.56, p < 0.0001). CONCLUSION: Abnormal fetal heart rate patterns occur in fetuses with absent end-diastolic velocity in the umbilical artery when the middle cerebral artery begins to lose its compensatory maximal dilation. The increase in the middle cerebral artery pulsatility index is associated with a significant reduction in left ventricular output without significant changes in right ventricular function. Thus it appears that a loss of autonomic reactivity occurs in the brain first and is followed within a few days by a similar response in the heart, as shown by the decreased fetal heart rate variation.

Blood Flow Velocity↗
PubMed1994

Transvaginal sonography, color flow imaging, computed tomographic scanning, and CA 125 as a routine follow-up examination in women with pelvic tumor: detection of recurrent disease.

We were trying to determine whether transvaginal sonography combined with color flow imaging should be used routinely for detecting recurrent pelvic tumors in patients treated for pelvic cancer. Eighteen patients who had completed their treatment for pelvic tumor were examined every 6 months by gynecologic examination, a CT scan, serum CA 125 levels, and transvaginal sonography with color flow imaging. Laparotomy or fine-needle biopsy was performed when a recurrent pelvic mass was observed or suspected on CT scans or transvaginal sonography. In nine of 18 patients a recurrent pelvic tumor was observed or suspected on CT scans or on transvaginal sonography. A recurrent pelvic tumor was diagnosed on laparotomy in five patients. In four patients, only a fine-needle biopsy was performed and only two of them had positive results. The highest sensitivity and specificity for detecting recurrent pelvic tumors were achieved by transvaginal sonography (100 and 91%, respectively) and by color flow imaging (86 and 100%, respectively). Intratumoral blood vessels were detected in all cases with recurrent pelvic tumors, and in only one of these cases the PI was high. We recommend a routine follow-up with transvaginal sonography in women completing their treatment for pelvic tumors. When a recurrence of tumor is only suspected on transvaginal sonography, color flow imaging may be used as an additional diagnostic tool.

Aged↗
PubMed1994

Doppler velocimetry. Where does it belong in evaluation of fetal status?

Doppler velocimetry is very useful as an antepartum surveillance tool that is able to detect pathologies of the fetus and predict the development of acidosis and hypoxia. Appropriate use can help us to decrease the mortality and morbidity in identifying earlier compromised fetuses.

Blood Flow Velocity↗
PubMed1993

Prenatal diagnosis of gall bladder anomalies--report of 17 cases.

We describe here 17 cases of fetal gall bladder anomalies, detected as early as the 14th week of gestation, out of 10,016 fetal systemic examinations performed by us in the last 6 years (0.15 per cent). In seven cases, agenesis of the fetal gall bladder was detected. The diagnosis was confirmed by post-abortal examination in five cases and in two post-partum. In six other cases, a left-sided gall bladder and in one case, a 'floating' gall bladder were detected at 15 weeks' gestation. In two cases, a septated or bilobed gall bladder was visualized. None of these 15 cases was dyskaryotic, but in five cases, two with agenesis and three left-sided gall bladders were associated with other fetal malformations. In two other cases, the gall bladder appeared dysmorphic on sonographic examination and in both of them intrauterine growth retardation and other anomalies were detected. Trisomy 18 was diagnosed by amniocentesis in one of them. According to our experience, failure to visualize the fetal gall bladder by the 15th gestational week is diagnostic of its absence and should raise the differential diagnosis between gall bladder atresia, which has a good prognosis, and external biliary atresia, which has a poor prognosis. Further experience is needed to characterize the various gall bladder malformations and their prognosis.

Female↗
PubMed1993

Pregnancy after liver transplantation.

Two patients who became pregnant after liver transplantation for end-stage liver disease were carefully monitored using pulsed Doppler waveform measurements. One patient with Wilson's disease, on triple immunosuppressive therapy including prednisone, azathioprine and low-dose cyclosporin A, delivered a healthy girl weighing 2650 g after 38 weeks' gestation. The other patient, with HBV-related postnecrotic cirrhosis, became pregnant less than 3 months postoperatively, under triple therapy, after being amenorrheic for 6 years. Episodes of elevation in liver enzymes were noted, and severe osteoporosis with low back pain developed. A healthy boy weighing 2975 g was born at 35 weeks' gestation. Our cases add to previous reports of successful pregnancies under cyclosporin A immunosuppression.

Adult↗
PubMed1993

The value of Doppler ultrasonography in prolonged pregnancies.

One hundred forty-two gravid women at term were followed prospectively by a non-stress test, estimation of amniotic fluid volume and Doppler velocimetry of the umbilical and uterine arteries. Adverse perinatal outcome was detected in 12 women (8.5%). Abnormal antepartum tests were detected in 26 women (17%). Seven women had an abnormally elevated resistance index (RI) in the umbilical artery; but only two had an abnormal outcome. Seven women had an abnormally elevated RI in the uterine artery, but only two had abnormal outcome. Three out of 11 women with oligohydramnion had abnormal perinatal outcome. Only one out of seven women with an abnormal non-stress test had abnormal perinatal outcome. In six women, more than one antepartum test was abnormal. The various surveillance methods demonstrated a low sensitivity (the highest was obtained by estimating amniotic fluid volume: 25%) and a low positive predictive value (the highest obtained by measuring the resistance index in either the umbilical or the uterine arteries: 28.6%). By considering any abnormal test as a positive test result for a given patient, a substantial improvement in sensitivity (66.7%) and positive predictive value (33.3%) are obtained. Doppler velocimetry adds very little in itself to the follow-up of patients with post-term gestations. However, when combined with additional antepartum tests, it may increase our ability to predict the compromised fetus in this condition.

Adolescent↗
PubMed1993

Assessment of ovarian and uterine blood flow by transvaginal color Doppler in ovarian-stimulated women: correlation with the number of follicles and steroid hormone levels.

OBJECTIVE: To study the changes that occur in vascular resistance to flow in the utero-ovarian circulation and their correlation with the number of follicles and steroid hormone levels in patients undergoing ovarian stimulation with gonadotropin. DESIGN: In a prospective study, the impedance to flow in the intraovarian and uterine vessels was measured by means of transvaginal color flow Doppler imaging throughout the cycle. SETTING: University-based IVF program. PATIENTS: Eleven infertile patients undergoing ovarian stimulation with gonadotropin in preparation for IVF and ET. MAIN OUTCOME MEASURES: Intraovarian, uterine, and arcuate artery blood flow velocity waveforms, follicular growth, and serum E2 and P concentrations throughout the cycle. RESULTS: Pulsatility index (PI) of the intraovarian blood vessels and uterine artery decreased gradually during the follicular and luteal phase. The PI of the arcuate artery did not change significantly. The PI of the intraovarian blood vessels correlated with the number of follicles (> 15 mm; day of hCG). Serum E2 concentrations but not P demonstrated negative linear correlation with the PI of the intraovarian vessels and uterine artery. CONCLUSIONS: Induced cycles are associated with decreased impedance to blood flow in the utero-ovarian circulation. Intraovarian PI correlates negatively at each stage of the cycle with the eventual number of preovulatory follicles. Little or no changes are observed when the response to ovarian stimulation is poor.

Adult↗
PubMed1993

Umbilical and arcuate uterine artery flow velocity measurements during acute hemodialysis.

Dialysis during pregnancy is a rare event associated with a poor outcome. The acute fluid volume shifts during hemodialysis are suspected to be one of the reasons for the high rate of complications during the procedure. This is the first report of uteroplacental and fetoplacental perfusion assessment during acute hemodialysis in pregnancy. The results of the Doppler measurements suggest that the maternal-fetal circulation can successfully tolerate acute volume shifts provoked by hemodialysis.

Adult↗