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Biomedical subjects

J A Copel

Publications and source records attributed to J A Copel.

At least 73 records · Page 4Linked to original sources
PubMed1995

Abdominal venous system in the normal fetus.

OBJECTIVE: To assess flow velocity waveforms of the abdominal venous system in the normal fetus. METHODS: Sixty-seven normal fetuses between 17-42 weeks' gestation were each studied once. Flow velocity waveforms were obtained from the following: 1) umbilical vein at the entrance into the abdomen, 2) umbilical sinus, 3) portal vein before its division, 4) anterior division of the portal vein, 5) posterior division of the portal vein, 6) ductus venosus at its origin from the umbilical vein, 7) splenic vein at its origin, 8) splenic vein close to the umbilical sinus, 9) renal vein, 10) adrenal vein, 11) common iliac vein before the origin of the inferior vena cava, 12) inferior vena cava, and 13) left hepatic vein. RESULTS: Five different patterns were noted on the velocity waveforms of the abdominal venous system: continuous, monophasic, biphasic, triphasic, and tetraphasic. CONCLUSION: In the normal fetus, all veins leading to the liver have continuous flow, except the umbilical sinus, which has a monophasic pattern. The ductus venosus has a biphasic pattern. The veins that open into the inferior vena cava have triphasic flow velocity waveforms. The left hepatic vein occasionally has a tetraphasic pattern.

Abdomen↗
PubMed1995

Thrombomodulin levels in preeclampsia, gestational hypertension, and chronic hypertension.

OBJECTIVE: To measure the circulating levels of thrombomodulin in women with preeclampsia, gestational hypertension, and chronic hypertension. METHODS: Serum levels of thrombomodulin were measured in 34 women with preeclampsia, 15 with gestational hypertension, 11 with chronic hypertension, and 34 normotensive pregnant women in the third trimester. Preeclampsia, gestational hypertension, and chronic hypertension were defined by ACOG criteria. Soluble thrombomodulin antigen was measured by a two-site enzyme-linked immunosorbent assay. RESULTS: Mean (+/- standard error) serum thrombomodulin levels were significantly higher in patients with preeclampsia (69.7 +/- 6.3 ng/mL) than in those with gestational hypertension (46.0 +/- 3.2 ng/mL) or chronic hypertension (46.2 +/- 3.3 ng/mL), and normotensive controls (50.1 +/- 3.1 ng/mL). There were no significant differences among the gestational hypertension, chronic hypertension, and normotensive control groups. CONCLUSION: Thrombomodulin may serve as a clinically meaningful marker to differentiate preeclampsia from other forms of hypertensive disorders in pregnancy.

Adult↗
PubMed1995

Fifth digit measurement in normal pregnancies: a potential sonographic sign of Down's syndrome.

The objective of the study was to obtain measurements of the fetal fifth finger, as a basis for further studies and for future comparison with fetuses with Down's syndrome. The study group included 173 karyotypically normal fetuses at 15-23 weeks' gestation. Routine biometric measurements were obtained on all, including biparietal diameter (BPD), femoral length (FL) and humeral length (HL), and the length of the fetal fifth finger. Linear growth of the fifth finger was observed across the range of gestational ages (GA), and a linear correlation was shown to exist between the length of the fifth finger and gestational age (y = -7.804 + 0.9079 x GA; r = 0.923; p < 0.0001), biparietal diameter (y = -3.7010 + 0.3043 x BPD; r = 0.913; p < 0.0001), femoral length (y = -0.0983 + 0.3406 x FL; r = 0.926; p < 0.0001), and humeral length (y = -1.3453 + 0.3982 x HL; r = 0.929; p < 0.0001). These results provide normative data of the length of the fetal fifth finger across a range of gestational ages. These data may provide an additional screening parameter for the prenatal detection of Down's syndrome.

Anthropometry↗
PubMed1995

Diagnosis of fetal anemia with Doppler ultrasound in the pregnancy complicated by maternal blood group immunization.

We investigated whether Doppler measurement of the fetal middle cerebral artery peak systolic velocity can be used to detect fetal anemia in pregnancies complicated by maternal blood group immunization. We first studied normal values for the middle cerebral artery peak systolic velocity in 135 fetuses (Group A), and also in 23 fetuses at risk for anemia who underwent 56 cordocenteses to assess the fetal hematocrit (Group B). A test to detect fetal anemia, based on the middle cerebral artery peak systolic velocity, was developed by using the data of the fetuses of Group A and Group B. Successively, the middle cerebral artery peak systolic velocity was prospectively determined in 16 fetuses at risk for anemia who underwent 42 cordocenteses (Group C) to assess the test developed, in a multicenter prospective fashion, by using the data of Group A and Group B. In the normal fetuses an exponential model expressed the increase of the middle cerebral artery peak systolic velocity values with advancing gestation. By using the data of the fetuses of Group A and Group B, four zones of anemia risk were identified. In Group C, none of the anemic fetuses had the middle cerebral artery peak velocity below the normal mean value, whereas all of the anemic fetuses had the peak velocity above the normal mean. The middle cerebral artery blood velocity increases with advancing gestation and is a non-invasive method of detecting anemia in pregnancies complicated by maternal blood group immunization.

Adult↗
PubMed1995

Blood flow velocity waveforms of the abdominal arteries in appropriate- and small-for-gestational-age fetuses.

The aim of this study was to describe flow velocity waveforms of abdominal arteries in the appropriate- and small-for-gestational-age fetus. Splenic artery, superior mesenteric artery, hepatic artery and renal artery velocity waveforms were obtained from 57 appropriate-for-gestational-age and nine small-for-gestational-age fetuses with color flow Doppler ultrasonography. The pulsatility index was used to quantify the arterial waveforms. Repeated measure analysis of variance indicated significant differences in the pulsatility index values in both the appropriate-for-gestational-age and small-for-gestational-age fetuses. A multiple comparison test revealed a significantly lower value for the pulsatility index in the splenic artery when compared to that of the other vessels for both the appropriate- and small-for-gestational-age fetuses. In the small-for-gestational-age fetuses, a lower pulsatility index value was observed at the superior mesenteric artery level when compared to the renal artery. Because of its lower frequency of successful insonation, the hepatic artery was not considered for the analysis. In the normal fetus, the splenic artery had the lowest pulsatility index when compared to the other arteries we investigated. This difference remained in small-for-gestational-age fetuses, reflecting a lower vascular resistance at the fetal spleen in both normal and small-for-gestational-age fetuses. It appears that in small-for-gestational-age fetuses the renal artery has a higher pulsatility index than the superior mesenteric artery, suggesting a preferential distribution of blood flow to the bowel.

Abdomen↗
PubMed1995

Invasive techniques for prenatal diagnosis: current concepts.

Recent dramatic advances have been made in our understanding of the genetic basis of diseases. One result will be an increase in the number of pregnant women considered potential candidates for prenatal diagnosis. At the same time, the invasive techniques by which fetal specimens for prenatal diagnosis are obtained have come under increasing scrutiny in the lay press. Practicing obstetricians must have sufficient knowledge of the benefits, risks, and limitations of these techniques to respond to patient inquiries. This article reviews the commonly used invasive prenatal diagnostic methods, including amniocentesis, chorionic villus sampling, and fetal blood sampling, as well as less widely available techniques, such as fetal skin and liver biopsies. Such relevant issues as indications, timing, and fetal risks are covered.

Amniocentesis↗
PubMed1995

Management of the Rh-sensitized mother.

The approval by the FDA of Rh immune globulin in 1968 led to a decrease in the incidence of Rh isoimmunization. As a result, fewer cases are seen by both the perinatologist and neonatologist. Prompt identification and early referral of the isoimmunized mother to a tertiary center will facilitate optimal management incorporating the latest techniques. In selected clinical situations, the less invasive technique of amniocentesis can be offered in place of fetal blood sampling for Rh D typing. In the anemic fetus requiring intrauterine transfusions, delivery is the goal once lung maturity is documented. As described elsewhere in the issue, recent improvements in neonatal care have facilitated management of complications not seen in the fetus but potentially critical in the neonate.

Anemia↗
PubMed1994

Management outcome and follow-up of fetal tachycardia.

OBJECTIVES: The aim of this study was to evaluate fetal tachycardia and the efficacy of maternally administered antiarrhythmic agents and the effect of this therapy on delivery and postpartum management. BACKGROUND: Sustained fetal tachycardia is a potentially life-threatening condition in which pharmacologic therapy is reported to be effective. There is ongoing discussion about optimal management. METHODS: A group of 51 patients with M-mode echocardiographically documented fetal tachycardia was studied retrospectively. RESULTS: Thirty-three fetuses had supraventricular tachycardia; 15 had atrial flutter; 1 had two episodes of both; and 2 had ventricular tachycardia. Fetal hydrops was seen in 22 patients. Thirty-four fetuses received maternal therapy with either digoxin or flecainide as the first administered drug (additional drugs were given in 12). Drug treatment was successful in establishing acceptable rhythm control in 82% (84% without, 80% with hydrops). In the latter group the median number of drugs and number of days to conversion were higher. Three patients with fetal hydrops died. In 50% of cases, tachycardia reappeared at delivery: 9 neonates presented with atrial flutter, 14 with supraventricular tachycardia and 1 with ventricular tachycardia. Seventy-eight percent of the group had pharmacologic therapy by 1 month of age and 14% by 3 years. CONCLUSIONS: Fetal tachycardia can be treated adequately in the majority of patients, even in the presence of hydrops, and therefore emergency delivery might not be indicated. Digoxin and flecainide were drugs of first choice and produced no serious adverse effects in this series of patients. The majority of patients do not require prolonged therapy.

Atrial Flutter↗
PubMed1994

Growth of the fetal gall bladder in normal pregnancies.

Our objective was to obtain dimensions of the fetal gall bladder as a basis, for further studies and to establish normative data to assess deviations in growth. The study group included 183 normal pregnant women from 13 to 40 weeks' gestation. Routine biometric measurements were obtained on all fetuses, including biparietal diameter, head and abdominal circumferences and measurements of the long bones and the two diameters of the fetal gull bladder. The gall bladder area and circumference were calculated for each gestational age.A linear growth function was observed across the gestational age and a first-degree correlation was found to exist between gestational age and both the longitudinal (r = 0.77067; p < 0.00001; y = -0.41060 + 0.0907 x gestational age) and transverse (r = 0.602; p < 0.00001; y = 0.58567 + 0.01925 x gestational age) diameters of the fetal gall bladder. A significant correlation was also found between gull bladder area and gestational age (r = 0.6878; p < 0.00001), biparietal diameter (r = 0.72768; p < 0.00001), abdominal circumference (r = 0.71363; p < 0.00001) and femoral length (r = 0.72190; p < 0.00001). In addition, a significant correlation was found between gall bladder circumference and gestational age (r = 0.76181; p < 0.00001), biparietal diameter (r = 0.80039; p < 0.00001), abdominal circumference (r = 0.78030; p < 0.00001) and femoral length (r = 0.79694; p < 0.00001). These results provide normative data of the fetal gall bladder in various dimensions and across gestational age. In addition, the data offer the potential for prenatal diagnosis of additional lesions in the extrahepatic biliary duct system.

Journal Article↗
PubMed1994

Hyperechoic fetal bowel: the perinatal consequences.

A number of publications have reported an association between the finding of hyperechoic fetal bowel on prenatal sonogram and disorders such as aneuploidy and cystic fibrosis. To define more precisely the significance of this finding, we systematically reviewed the published material on the subject. Based on a total of 357 reported cases, we documented a high prevalence of cystic fibrosis (25.6 per cent) and chromosome abnormality (12.4 per cent) associated with increased bowel echogenicity in the fetus. High rates of intrauterine growth retardation (14.9 per cent), fetal demise (9.0 per cent), and prematurity (15.3 per cent) were also found. The data were obtained from a population at high a priori risk for aneuploidy and included fetuses at 1 in 4 risk for cystic fibrosis reported in two studies. This increased the bias towards an adverse outcome. The rate of complications when a hyperechoic abdomen is noted in a low-risk fetal population has so far not been delineated. Although the high frequency of complications found is of concern and warrants investigation, extrapolation of these risk figures to a fetal population at low a priori risk may not be appropriate.

Abdomen↗
PubMed1994

Color Doppler flow patterns and flow velocity waveforms of the intraplacental fetal circulation in growth-retarded fetuses.

OBJECTIVE: We examined intraplacental color Doppler flow patterns and spectral Doppler flow velocity waveforms of villous arteries in pregnancies with intrauterine growth retardation. STUDY DESIGN: A total of 192 uncomplicated pregnancies and 29 pregnancies with intrauterine growth retardation between 26 and 41 weeks' gestation were examined in this cross-sectional study. Intraplacental color Doppler flow findings and pulsatility indexes of umbilical and villous arteries were correlated with the presence of intrauterine growth retardation and multiple outcome variables. Villous arteries were identified by their intraplacental color Doppler flow image, and flow velocity waveforms were obtained by superimposition of pulse-wave Doppler. RESULTS: (1) Intraplacental color Doppler flow signals from two or more villous arteries were detected in all 192 normal pregnancies but were undetectable in 8 of 29 fetuses with intrauterine growth retardation (27.6%, p < 0.0001). Absence of intraplacental color Doppler flow signals was associated with fetal distress in 6 of 8 cases (87.5%) and perinatal death in two cases (25.0%), compared with 3 of 21 (14.2%, p < 0.005) and 0 of 21 (not significant) cases of intrauterine growth retardation with detectable intraplacental color Doppler flow. Median Apgar scores at 1 minute were 5 and 8 (p < 0.05), respectively, and at 5 minutes were 8 and 8 (not significant), respectively. (2) Umbilical artery flow velocity waveforms were abnormal (> 95th percentile) in 8 of 21 cases of intrauterine growth retardation (38.0%) with detectable intraplacental color Doppler flow, including two cases with reversed end-diastolic flow. In contrast, the corresponding villous artery flow velocity waveforms were abnormal in only 1 of 21 cases (p < 0.04). CONCLUSION: (1) Failure to detect intraplacental color Doppler flow signals is associated with intrauterine growth retardation and fetal distress. (2) Flow velocity waveforms of detectable villous arteries are usually normal in intrauterine growth retardation, even in the presence of extremely abnormal umbilical artery flow velocity waveforms.

Blood Circulation↗
PubMed1994

Routine ultrasound screening.

In the USA, the cost-effective use of health-care dollars is currently of great importance. The routine use of technology such as ultrasound will undergo great scrutiny. Both the American College of Obstetricians and Gynecologists and the US National Institutes of Health have recommended that ultrasound be used only for indicated reasons because of concerns about safety and efficacy.

Congenital Abnormalities↗
PubMed1994

The real-time and color Doppler appearance of adrenal neuroblastoma in a third-trimester fetus.

BACKGROUND: Neuroblastoma is the second most common malignant tumor of childhood. With the increasing use of ultrasound, prenatal recognition of this tumor is becoming more common. CASE: A 33-year-old woman presented at 38 weeks' gestation. A mass at the level of the left fetal renal pole was identified upon ultrasonography. Color Doppler and flow mapping were also evaluated. CONCLUSION: Ultrasound evaluation, color flow mapping, and Doppler flow studies of fetal neuroblastoma may be helpful in both diagnosis and management.

Adrenal Gland Neoplasms↗
PubMed1994

Ectopic atrial tachycardia in utero.

BACKGROUND: The antenatal diagnosis of fetal arrhythmias helps direct medical management, which may include intrauterine therapy. Ectopic atrial tachycardia is an unusual arrhythmia in children, and we know of no previous reports of antenatal diagnosis of this particular arrhythmia. CASE: The diagnosis of fetal ectopic atrial tachycardia was suggested by the monitor tracing during labor and was subsequently confirmed by the postpartum behavior of the arrhythmia and its electrocardiographic characteristics. CONCLUSION: Ectopic atrial tachycardia, although uncommon, should be considered in the differential diagnosis of fetal tachycardias. The fetal monitor tracing may be useful in making this diagnosis antenatally, which may help to direct management both before and after birth.

Adult↗
PubMed1993

First-trimester prenatal diagnosis of osteogenesis imperfecta type II by DNA analysis and sonography.

Osteogenesis imperfecta type II was diagnosed prenatally by analysis of DNA obtained from chorionic villus sampling (CVS) performed at 12 weeks of gestation in a woman who previously had had an affected child. The father had been shown to be mosaic for a mutation in the gene (COL1A2) which encodes the alpha 2(I) chain of type I collagen. An affected fetus was predicted by detection of the mutation in amplified chorionic villus genomic DNA. Ultrasound examination at 13 weeks 4 days demonstrated femoral deformity and virtual absence of calvarial mineralization. In pregnancies at risk for osteogenesis imperfecta type II, sonographic evidence of skeletal abnormalities may be evident by 13 weeks' gestation.

Adult↗