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Biomedical subjects

J C Hobbins

Publications and source records attributed to J C Hobbins.

At least 37 records · Page 2Linked to original sources
PubMed1995

Single umbilical artery: does it matter which artery is missing?

OBJECTIVE: Our purpose was to determine whether the presence of congenital anomalies in fetuses with a single umbilical artery is related to the side of the missing artery. STUDY DESIGN: During an 18-month prospective study, the side of the missing artery was identified in all pregnancies with a single umbilical artery (n = 77). Targeted sonograms and perinatal follow-up were obtained. RESULTS: The left umbilical artery was absent in 56 of 77 (73%) fetuses, compared with 21 of 77 (27%) for the right artery, p < 0.0001. Congenital anomalies occurred in 20 of 77 (26%) fetuses, with 16 of 56 (29%) in those with absence of the left artery and 4 of 21 (19%) in those with absence of the right artery, p = 0.561. Complex congenital anomalies occurred in 9 of 20 (45%) fetuses. All complex anomalies had absence of the left artery, p = 0.103. Cytogenetic abnormalities were noted in 6 fetuses, all with absence of the left artery, p = 0.181. In fetuses with a single umbilical artery as an isolated finding, small-for-gestational-age fetuses occurred in 4 of 50 (8%) pregnancies. CONCLUSION: In fetuses with a single umbilical artery the left artery is more commonly absent than the right artery. In our series cytogenetic and complex fetal anomalies occurred exclusively in fetuses with absence of the left artery. In contrast to previous reports, the incidence of small-for-gestational-age fetuses does not appear to be increased in cases of an isolated single umbilical artery.

Adolescent↗
PubMed1995

Ultrasonographic assessment of fetal growth: comparison between human and ovine fetus.

OBJECTIVE: Our purpose was to evaluate the rate of ovine fetal growth for several body parameters by serial ultrasonographic measurements and to compare them with analogous data in the human fetus. STUDY DESIGN: Forty-three ewes with singleton gestations were studied. Four parameters were measured: biparietal diameter, abdominal circumference, femur length, and tibia length. Ultrasonographic examinations were performed weekly from 50 to 138 days of gestation (term 147 days). Quadratic regression analysis was used to describe each data set. RESULTS: The biparietal diameter showed a significant deceleration of its growth rate. The abdominal circumference showed a linear growth pattern. Both femur and tibia revealed a significant acceleration of the growth rate. CONCLUSION: The ovine fetal growth pattern is different from that observed in the human fetus, in which all four parameters show deceleration of the growth rate in late gestation. In comparison to the ovine, the human fetus reaches similar abdominal circumference and femur length values at term, but in a gestational period that is twice as long. In sharp contrast to abdominal circumference and femur length growth, the biparietal diameter has a similar growth rate in both species. Thus the human fetus has a slower rate of somatic growth and its greater biparietal diameter at term results from the longer gestational period.

Abdomen↗
PubMed1995

Early ultrasonographic detection of fetal growth retardation in an ovine model of placental insufficiency.

OBJECTIVE: Our aims were as follows: (1) to determine whether fetal growth retardation can be detected noninvasively with ultrasonography in ewes and (2) to establish the time interval between exposure of ewes to environmental stress that causes growth retardation (heat stress) and detection of growth lag for specific fetal body measurements. STUDY DESIGN: Four ewes were exposed to heat stress for 80 days starting at 35 days' gestation. (The duration of pregnancy in sheep is 147 days). Serial ultrasonographic measurements of fetal biparietal diameter, abdominal circumference, and femur and tibia lengths were obtained beginning at 50 days' gestation. Growth curves were calculated for each parameter and compared with growth curves obtained from 43 normal fetuses. RESULTS: Biparietal diameter measurements deviated significantly from normal starting at 90 days' gestation (p < 0.05). Abdominal circumference diverged at 70 days' gestation (p < 0.05), and both femur and tibia length diverged at 80 days (p < 0.05). The regression lines showed significant differences for all the parameters in both slope (p < 0.01) and intercept (p < 0.01). CONCLUSIONS: Fetal growth retardation can be detected noninvasively by ultrasonography after approximately 5 weeks of exposure to heat stress. Fetal growth continues throughout gestation but at a slower rate than normal and according to a pattern similar to that observed in asymmetrically growth-retarded human fetuses. Early detection of stunted fetal growth in an animal model is important for testing intervention strategies in the treatment of fetal growth retardation.

Abdomen↗
PubMed1995

Ultrasonography in the detection of aneuploidy in the first trimester.

Ultrasonography has been used increasingly in the first trimester to identify fetal anomalies as early as possible in gestation. First trimester sonographic screening may detect a greater proportion of aneuploid fetuses than sonography performed later in pregnancy, and it may allow determination of potential markers for prediction of chromosomal anomalies.

Aneuploidy↗
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

Transvaginal ultrasonography and transabdominal embryoscopy in the first-trimester diagnosis of Smith-Lemli-Opitz syndrome, type II.

OBJECTIVE: Our goal was to demonstrate the efficacy of transabdominal embryoscopy in the first trimester of pregnancy. STUDY DESIGN: A patient at risk for Smith-Lemli-Opitz syndrome, type II, was referred for prenatal diagnosis at 11 weeks 5 days of gestation. RESULTS: A transvaginal ultrasonographic examination revealed the presence of a nuchal membrane and bilateral polydactyly. A transabdominal embryoscopy confirmed the diagnosis of polydactyly. The patient had an unremarkable postprocedure course before termination of pregnancy 5 days later. In a second pregnancy embryoscopy revealed a normal fetal hand despite a suggestion on transvaginal ultrasonography that there was polydactyly. On the basis of this information the patient elected to continue the pregnancy, and a normal baby was delivered at 35 weeks. CONCLUSION: This case validates the efficacy of noninvasive and invasive techniques, used adjunctively, in the first-trimester diagnosis of a lethal fetal condition composed of subtle phenotypic manifestations.

Abnormalities, Multiple↗
PubMed1994

Fetal responses to maternal exercise: effect on fetal breathing and body movement.

This study was conducted to determine the impact of maternal exercise on fetal breathing and fetal body movement, which are commonly used for assessing fetal well-being. Twelve healthy patients with a range of gestational ages of 26 to 36 weeks, who actively exercised throughout pregnancy, participated in the study. The patients walked on a motorized treadmill using a modified Bruce protocol until the maternal heart rate reached 75% of the age-predicted maximal heart rate. Fetal activities (fetal breathing and fetal body movement) were continuously monitored with real-time ultrasonography for 20 minutes before and after the standardized exercise test. Our results demonstrate that there is a significant increase in maternal heart rate and blood pressure associated with exercise. In addition, there is a significant decrease in the total duration and frequency of fetal breathing and fetal body movements following acute maternal exercise.

Adult↗
PubMed1993

Fetal blood sampling and cytogenetic abnormalities.

From September 1984 to April 1991, we performed cytogenetic analysis on fetal blood samples from 214 second- and third-trimester pregnancies. One hundred and thirty-four cases were referred to consider the possibility of chromosomal mosaicism following amniocyte studies. The confirmation rate of mosaicism is at 0 per cent (0/9), 1.4 per cent (1/70), and 40 per cent (22/55) for cases of level I, level II, and level III mosaicism, respectively. Four out of 17 cases were positive for the diagnosis of fragile X syndrome. Of 63 cases with abnormal ultrasound findings, blood disorders, or other genetically related clinical conditions, 11 were found to have a chromosome abnormality. Fetal blood sampling is a valuable adjunct to other methods in the prenatal diagnosis of chromosomal mosaicism or pseudomosaicism. It is also useful when rapid cytogenetic diagnosis is desired because of malformations detected in pregnancies at a late gestational age.

Cells, Cultured↗
PubMed1993

Transabdominal thin-gauge embryofetoscopy: a technique for early prenatal diagnosis and its use in the diagnosis of a case of Meckel-Gruber syndrome.

OBJECTIVE: Our aim was to develop and evaluate a transabdominal endoscopic technique to visualize the embryo or fetus with thin-gauge needles and submillimetric fiberoptic endoscopes. METHODS: Under ultrasonographic guidance, an 18- or 19-gauge thin-wall needle was introduced into the uterus of 28 patients undergoing first-trimester or early second-trimester termination of pregnancy. A 0.7 mm endoscope was threaded through the lumen of the needle after removal of the stylet. Visualization of the embryo-fetus was attempted before 14 weeks' gestation (n = 20). From 16 to 20 weeks (n = 8), the needle and endoscope were directed to the placental insertion of the umbilical cord, and a cordocentesis was performed. RESULTS: Excellent visualization of the surface anatomy of fetuses from 7 to 13 weeks was obtained in 85% of cases (17/20). A diagnosis of Meckel-Gruber syndrome was made at 11 weeks' menstrual age by visualizing postaxial polydactyly and an occipital encephalocele. Endoscopically assisted cordocentesis allowed visualization of the lumen of the umbilical vein and of the blood flow within it. CONCLUSION: Endoscopic visualization of the embryo or fetus can be performed transabdominally in the first trimester with small-delivered endoscopes. This represents a clear advantage over previous endoscopic approaches to the human pregnancy. Potential applications of this technique include a precise description of fetal anatomy and physiologic features, diagnosis of anomalies, and therapeutic fetal interventions.

Abdomen↗
PubMed1993

Embryoscopic demonstration of hemorrhagic lesions on the human embryo after placental trauma.

OBJECTIVE: The purpose of this study was to evaluate embryoscopically the effect of placental trauma on the human embryo. STUDY DESIGN: Patients undergoing elective first-trimester termination of pregnancy underwent transcervical embryoscopy both before and after chorionic villus sampling. If hemorrhagic lesions were not observed on the fetus after chorionic villus sampling, partial placental detachment was performed with a blunt instrument, and the fetus was again observed. RESULTS: Hemorrhagic lesions were observed in 20 of 43 fetuses. In 13 of them, the lesions occurred after placental trauma with the chorionic villus sampling catheter alone (30%), whereas lesions were observed in the remaining seven patients after additional blunt placental disruption. The lesions were located most frequently on the cephalic region, and they grew in size during the observation period. Gestational age or amount of chorionic villus sampling tissue was not different between fetuses with or without lesions. CONCLUSION: Placental trauma results in embryoscopically demonstrable hemorrhagic lesions on the human embryo. Whereas some of these lesions may be of no consequence, others may lead to permanent changes. If similar lesions occur in deeper tissues, they could cause disruptions in development and conceivably could be related to anomalies reported in infants born to women who have had chorionic villus sampling procedures. Embryoscopy affords the opportunity to study possible mechanisms involved in the occurrence of anomalies.

Cervix Uteri↗
PubMed1993

Erythropoietin in human fetuses with immune hemolytic anemia and hydrops fetalis.

OBJECTIVE: To determine whether plasma erythropoietin is increased in fetuses with anemia due to Rh isoimmunization. METHODS: Hemoglobin and erythropoietin were measured in samples obtained by funipuncture from 15 fetuses with Rh isoimmunization (gestational age 26.2 +/- 5.0 weeks, mean +/- standard deviation) and from 13 control fetuses (23.1 +/- 6.7 weeks). Hemoglobin and erythropoietin also were determined in umbilical cord blood collected at birth from 20 term fetuses delivered by elective cesarean. RESULTS: Fetuses with Rh isoimmunization had lower hemoglobin and higher plasma erythropoietin measurements than mid-gestation controls (6.1 +/- 3.9 versus 10.7 +/- 1.5 g/dL and 105.5 +/- 168.1 versus 12.5 +/- 3.1 mU/mL, P < .05, respectively). Hemoglobin and plasma erythropoietin increased with gestational age in control fetuses. There was an inverse association between hemoglobin and plasma erythropoietin in control and Rh-isoimmunized fetuses (r = -0.56, P < .005). Using multiple linear regression, hemoglobin and gestational age were associated independently with plasma erythropoietin (overall F2,25 = 12.3, multiple r2 = 0.49, P < .001). Despite marked decreases in hemoglobin, fetuses below 24 weeks' gestation had minimal increases in plasma erythropoietin compared to fetuses above that gestational age. Mildly anemic Rh-isoimmunized fetuses (hemoglobin 11.6 +/- 2.0 g/dL) delivered vaginally had significantly higher erythropoietin levels in umbilical cord plasma than Rh-isoimmunized fetuses with comparable hemoglobin (10.9 +/- 3.5 g/dL) delivered by elective cesarean without labor (1246 +/- 856 versus 106 +/- 66 mU/mL, respectively, P < .05). CONCLUSION: Fetuses with anemia at mid to late gestation respond with increases in plasma erythropoietin, but these changes are substantially attenuated before 24 weeks' gestation.

Anemia, Hemolytic, Autoimmune↗
PubMed1993

Isolated fetal pleural effusion: a prenatal management dilemma.

OBJECTIVE: To determine the etiology, pregnancy complications, and outcome of isolated fetal pleural effusion diagnosed antenatally and to evaluate the benefits of prenatal fetal interventions. DATA SOURCES: A literature search of MEDLINE was performed for relevant English language publications between 1985-1991. In addition, reference lists of articles were used to identify reported cases of isolated fetal pleural effusion. METHODS OF STUDY SELECTION: Our search uncovered 31 papers published in peer review journals. From these reports, 82 cases met our selection criteria: All fetuses were diagnosed antenatally with pleural effusion and had no other signs of hydrops at initial diagnosis. DATA EXTRACTION AND SYNTHESIS: The etiology of isolated fetal pleural effusion was unknown in most cases. Possible causes included congenital chylothorax, goiter, lung tumors, and infection. Cardiac defects (4.9%), Down syndrome (4.9%), and polydactyly (1.2%) may be associated with isolated fetal pleural effusion. Perinatal mortality was high (36%) and was related to the development of nonimmune hydrops, prematurity, and pulmonary hypoplasia. Early gestational age at diagnosis of isolated fetal pleural effusion (32 weeks or less) was associated with poor outcome and a neonatal death rate of 55%. In contrast, the neonatal death rate approached 31% as gestational age at diagnosis exceeded 32 weeks. Fifty-four cases were managed conservatively whereas 24 received intrauterine intervention, which included either pleuroamniotic shunt or repeated thoracenteses. Neonatal death rates were 37 and 33%, respectively. CONCLUSION: Not enough data exist to support either the conservative approach or intrauterine pleural drainage in cases of isolated fetal pleural effusion diagnosed antenatally.

Female↗
PubMed1992

Sonography of fetal Dandy-Walker malformation: a reappraisal.

Thirty-four cases of fetal Dandy-Walker malformation recognized in utero with ultrasound between 16 and 37 weeks' gestation are reported. In each case a qualitative examination of the posterior fossa structures was performed, including the cerebellar hemispheres, cerebellar vermis, fourth ventricle and cisterna magna. In each case, the transverse cerebellar diameter and the depth of the cisterna magna were measured in a standard transcerebellar view of the fetal brain. The atrial width of the lateral ventricles was also assessed. The transverse cerebellar diameter was abnormal in 15 cases, the cisterna magna depth was abnormal in 33, and the atrial width was abnormal in 30. It is concluded that measurement of the transverse cerebellar diameter is unreliable in predicting fetal Dandy-Walker malformation. Measurements of the cisterna magna and atrium seem to be more valuable, although the real sensitivity remains unclear. In pregnancies at risk for fetal Dandy-Walker malformation, the sonographic examination should not be limited to the cerebral ventricles and transcerebellar view but should include a detailed evaluation of all the different anatomical components of the posterior fossa, especially the fourth ventricle and inferior cerebellar vermis.

Journal Article↗
PubMed1992

Atelosteogenesis type II: sonographic and radiological correlation.

Atelosteogenesis type II is a lethal chondrodysplasia characterized by severe micromelia, spinal abnormalities, talipes equinovarus, and abducted thumbs and toes. We present a case diagnosed at 21 weeks of gestation in which antenatal sonographic and post-mortem radiological findings were correlated. The patient had a recurrence of this disorder in a subsequent pregnancy which was terminated at 15 weeks, supporting previous reports of an autosomal recessive inheritance pattern. The feasibility of diagnosing the following morphological features by prenatal ultrasonography is demonstrated: coronal clefts of the vertebral bodies, metaphyseal and epiphyseal abnormalities, spinal deviations such as cervical kyphosis and a horizontal sacrum, additional ossification centres in the pelvis, and preaxial deviation of the thumbs and toes. The differential diagnosis of this disorder from other skeletal dysplasias with similar features is discussed.

Abnormalities, Multiple↗