bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuchal translucency measurement and pregnancy outcome in karyotypically normal fetuses
Authors: Michailidis G. D. , Economides D. L. 
Published: March 2003

AbstractObjectiveThe aim of the study was to evaluate the use of nuchal translucency measurement as a marker of adverse pregnancy outcome in karyotypically normal fetuses.MethodsDuring the years 1995–99, nuchal translucency (NT) measurement was routinely offered to all women who had their dating scan in our unit. From the data collected, we calculated the 95th and 99th centiles of the NT for a given crown–rump length using regression analysis. The NT measurements were analyzed in relation to pregnancy outcome, especially with regards to miscarriage, intrauterine death and diagnosis of fetal structural abnormalities, after excluding chromosomal abnormalities.ResultsThe pregnancy outcome was available in 6650 (89%) of the 7500 pregnancies. In fetuses with an NT over the 99th centile, 17.8% (relative risk 12.2, 95% CI 7.2–20.8) had an adverse pregnancy outcome (miscarriage, intrauterine death, or termination for fetal abnormality) versus 1.5% for those with a normal measurement. The incidence of structural abnormalities, especially heart defects, was significantly increased in the high‐NT groups. Three out of 11 fetuses with major cardiac abnormalities had an NT measurement over the 99th centile. The calculated relative risk for major heart defects in fetuses with increased NT was 33.5 (95% CI 9–123).ConclusionIn the setting of routine antenatal screening, an increased NT measurement is a marker of a high‐risk pregnancy even in karyotypically normal fetuses. In addition, the increased incidence of structural abnormalities makes the close follow‐up of these pregnancies imperative and should include specialized fetal echocardiography. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Fetal hydrops and hepatosplenomegaly in the second half of pregnancy: a sign of myeloproliferative disorder in fetuses with trisomy 21
Authors: Smrcek J. M. , Baschat A. A. , Germer U. , Gloeckner‐Hofmann K. , Gembruch U. 
Published: March 2003

AbstractObjectiveTo demonstrate the relationship between fetal hydrops and/or hepatosplenomegaly in the second half of pregnancy with a myeloproliferative disorder in fetuses with trisomy 21 or mosaic trisomy 21.DesignA retrospective case series.SubjectsCases were selected from 79 cases of trisomy 21 diagnosed in our prenatal unit between 1993 and 1999.MethodsAll fetuses had a detailed sonographic anatomic survey and biometry. Doppler of the umbilical and middle cerebral arteries, ductus venosus, inferior vena cava and umbilical vein was performed whenever possible. Two‐dimensional echocardiography supplemented by color Doppler flow mapping and spectral pulsed wave Doppler was performed in all cases of fetal hydrops. Fetal karyotyping was obtained by amniocentesis, chorionic villus sampling or fetal blood sampling. In the presence of fetal hydrops a cordocentesis was performed for fetal hematology, biochemistry and TORCH serology. In cases with diagnosis of myeloproliferative disorder, peripheral blast cells were characterized by microscopy, cytochemistry and determination of surface markers. All cases with myeloproliferative disorder were stillborn and subsequently had a postmortem examination performed.ResultsDuring the study period 79 cases of trisomy 21 were diagnosed. Eleven of these had fetal hydrops. Three of these fetuses presented with hepatosplenomegaly and myeloproliferative disorder in the second and third trimesters. In addition, one fetus with sonographic markers of trisomy 21, where karyotyping was unfortunately unsuccessful, presented with hepatosplenomegaly, hydrops and myeloproliferative disorder. In the four fetuses with hepatosplenomegaly and hydrops, serology was negative for congenital infection. The characteristics of blast cells in the peripheral blood smear revealed a myeloproliferative disorder.ConclusionFetal hydrops and/or hepatosplenomegaly in the second half of pregnancy, although suggestive of infectious etiology, may be a sign of myeloproliferative disorder in fetuses with trisomy 21 or mosaic trisomy 21. There is a possibility that a transient myeloproliferative disorder is a more common cause of mid or late‐trimester hydrops in cases of trisomy 21 than previously thought. In these hydropic fetuses the prognosis seems to be poor. On the other hand we can speculate that a myeloproliferative disorder and the associated hepatosplenomegaly and/or hydrops may show spontaneous remission or that the transient myeloproliferative disorder may be without any detectable ultrasonographic signs and therefore may be more frequent in utero than realized. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Third‐trimester transvaginal ultrasonography in placenta previa: does the shape of the lower placental edge predict clinical outcome?
Authors: Ghourab S. 
Published: March 2003

AbstractObjectiveTo evaluate the clinical significance of the shape of the lower placental edge in women with transvaginal sonographic diagnosis of placenta previa.DesignA prospective observational study at a tertiary teaching hospital.PopulationA total of 104 women with confirmed transvaginal sonographic diagnosis of placenta previa before 32 weeks' gestation.MethodsInitial transvaginal sonography was performed at between 28 and 32 weeks' gestation in 138 patients with either strong clinical suspicion or previous abdominal sonographic diagnosis of placenta previa in the early third trimester. The lower placental edge was found to be positioned over the internal cervical os in 33 women (complete previa) and within 3 cm from it in 71 women (low‐lying placenta). Patients with low‐lying placenta were followed up by serial transvaginal sonographic examinations until delivery; detailed information including the placental location (anterior or posterior), the distance of its edge from the internal cervical os and its thickness were recorded. The clinical outcomes of the 17 who had a thick‐edge low‐lying placenta were compared with those who had a thin‐edge one (54 women). In patients with complete placenta previa, demographic data, the shape of the lower placental edge whenever transvaginal sonography visualized it, and the clinical outcomes were documented. The incidence of major complications in thick‐edge or central placenta was compared to that in the thin‐edge group.ResultsWomen having a low‐lying placenta with a thick edge had a significantly higher rate of antepartum hemorrhage (P = 0.0002), abdominal delivery (P = 0.02), abnormally adherent placenta (P = 0.012) and low birth weight (P = 0.006) than those in whom the placental edge was thin. Cesarean hysterectomy was required in six patients with complete placenta previa because of severe peripartum hemorrhage; all of them had either central or thick‐edge placenta accreta.ConclusionWomen with placenta previa are at a relatively higher risk of developing complications if the lower placental edge is thick. Integration of the shape of the lower placental edge into transvaginal sonographic assessment of placenta previa may improve the prediction of mode of delivery and clinical outcome. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Ultrasound prenatal diagnosis of fetus in fetu
Authors: Mills P. , Bornick P. W. , Morales W. J. , Allen M. , Gilbert‐Barness E. , Johnson P. K. , Quintero R. 
Published: March 2003

AbstractA case of fetus in fetu was diagnosed prenatally using ultrasound. The differential diagnosis between a fetus in fetu and a highly differentiated teratoma is discussed. The importance of prenatal diagnosis of fetus in fetu and the effect on subsequent management are described. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Recurrent cytomegalovirus infection during pregnancy: ultrasonographic diagnosis and fetal outcome
Authors: Henrich W. , Meckies J. , Dudenhausen J. W. , Vogel M. , Enders G. 
Published: March 2003

AbstractFetal infection as a consequence of recurrent disease is uncommon. We present a case of recurrent cytomegalovirus infection in the second trimester of pregnancy. Fetal infection was detected through severely abnormal findings on ultrasound examination and verified by detecting cytomegalovirus DNA in the amniotic fluid and cytomegalovirus‐specific immunoglobulin M antibodies in the fetal blood and associated pancytopenia. Because of the severity of the infection, a fatal outcome was predicted. A Cesarean section was performed at 33 + 5 weeks of gestation; the child died shortly after birth. Copyright © 2002 ISUOG
Impact of laser coagulation in severe twin–twin transfusion syndrome on fetal Doppler indices and venous blood flow volume
Authors: Gratacós E. , Van Schoubroeck D. , Carreras E. , Devlieger R. , Roma E. , Cabero L. , Deprest J. 
Published: March 2003

AbstractObjectiveTo evaluate the impact of fetoscopic laser coagulation of placental anastomoses in severe twin–twin transfusion syndrome on fetal Doppler indices and umbilical vein blood flow volume as calculated with Doppler and two‐dimensional ultrasound.Methods Thirty‐two cases of second‐trimester severe twin–twin transfusion undergoing laser therapy were examined with serial ultrasound before and 1, 3 and 5 days after therapy. Pulsatility indices in the umbilical artery and ductus venosus were measured. Blood volume flow at the level of the intra‐abdominal umbilical vein was calculated by means of Doppler and two‐dimensional ultrasound. The development of hydropic signs in donors was recorded. Perinatal outcome in terms of neonatal survival was recorded for all cases.ResultsIn recipients, ductus venosus pulsatility index decreased progressively after therapy and, by day 5, median pulsatility index was significantly lower than that before therapy (0.97 vs. 0.82, P < 0.0001). Umbilical vein blood flow volume in recipient twins showed no significant variations before and after laser. In donors, umbilical artery pulsatility index decreased significantly by the first day following therapy (2.1 vs. 1.6, P < 0.0001). Previously absent or reverse umbilical end‐diastolic flow reappeared after therapy in 46% (7/15) of donors. Ductus venosus pulsatility index in donors increased significantly by day 1 after therapy (0.99 vs. 1.35, P < 0.0001) but, over days 3 and 5, it returned towards preoperative values. Umbilical vein flow volume measurements (mL/min/kg) in the donor increased by approximately 50% the day after treatment (151 vs. 232, P < 0.0001) and remained elevated. Umbilical vein flow volume before laser therapy was significantly lower in donors compared to recipients (151 vs. 260, P < 0.0001), but the difference was non‐significant after treatment (240 vs. 267). One or more hydropic signs developed in eight (25%) donors during the 5 days' observation after therapy.ConclusionsLaser therapy induced important changes in fetal hemodynamic parameters, resulting in a reversion of the disturbances associated with severe twin–twin transfusion syndrome. The recipient twin showed a progressive improvement of previous signs of right cardiac overload. The donor experienced a substantial increase in umbilical vein blood volume flow accompanied by a transitory state of relative right overload, which may explain the development of transient hydropic signs in a proportion of donors. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology
One‐stop clinic for assessment of risk for trisomy 21 at 11–14 weeks: a prospective study of 15 030 pregnancies
Authors: Bindra R. , Heath V. , Liao A. , Spencer K. , Nicolaides K. H. 
Published: March 2003

AbstractObjectiveTo evaluate the performance of a one‐stop clinic for assessment of risk (OSCAR) for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free β‐human chorionic gonadotropin (hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A) at 11–14 weeks of gestation.MethodScreening for trisomy 21 was carried out by OSCAR in 15 030 singleton pregnancies with live fetuses at 11–14 weeks. The estimated risk for trisomy 21 was calculated, and the women were counseled regarding this risk and the option of invasive testing or expectant management. Follow‐up of the outcome of all pregnancies was carried out. The detection and false‐positive rates for different risk cut‐offs were calculated.ResultsFetal NT and maternal serum free β‐hCG and PAPP‐A were successfully measured in all cases. Pregnancy outcome, including karyotype results or the birth of a phenotypically normal baby, was obtained from 14 383 cases. The median maternal age of these cases was 34 (range 15–49) years and in 6768 (47.1%) the age was 35 years or greater. The median gestation at screening was 12 (range 11–14) weeks and the median fetal crown–rump length was 64 (range 45–84) mm. The estimated risk for trisomy 21 based on maternal age, fetal NT and maternal serum free β‐hCG and PAPP‐A was 1 in 300 or greater in 6.8% (967 of 14 240) normal pregnancies, in 91.5% (75 of 82) of those with trisomy 21 and in 88.5% (54 of 61) of those with other chromosomal defects. For a fixed false‐positive rate of 5% the respective detection rates of screening for trisomy 21 by maternal age alone, maternal age and serum free β‐hCG and PAPP‐A, maternal age and fetal NT, and by maternal age, fetal NT and maternal serum biochemistry were 30.5%, 59.8%, 79.3% and 90.2%, respectively.ConclusionScreening for trisomy 21 by a combination of maternal age, fetal NT and maternal serum biochemistry at 11–14 weeks can be provided in an OSCAR setting and is associated with a detection rate of about 90% for a false‐positive rate of 5%. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal ultrasound findings in a fetus with congenital contractural arachnodactyly
Authors: Kölble N. , Wisser J. , Babcock D. , Maslen C. , Huch R. , Steinmann B. 
Published: March 2003

AbstractCongenital contractural arachnodactyly (CCA) or Beals–Hecht syndrome is an autosomal dominant disorder caused by mutations in the fibrillin‐2 (FBN2) gene. The principal features of CCA are a marfanoid habitus, multiple congenital contractures, camptodactyly, arachnodactyly, kyphoscoliosis, muscular hypoplasia, and external ear malformations.Our case is the first that shows typical sonographic signs in a fetus at 25 weeks' gestation with molecular genetically verified CCA in a large family with many members affected over four generations. This demonstrates that CCA can be detected prenatally by non‐invasive ultrasonography. The importance of confirmation of CCA by means of DNA sequence analysis of the FBN2 gene is stressed. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Bedside estimation of Down syndrome risk during first‐trimester ultrasound screening
Authors: Herman A. , Dreazen E. , Herman A. M. , Batukan C. E. M. , Holzgreve W. , Tercanli S. 
Published: March 2003

AbstractObjectiveTo construct tables for ‘bedside’ estimation of Down syndrome risk based on maternal age and nuchal translucency measurements.MethodsLikelihood ratios were calculated using the log multiple of median Gaussian model. The parameters for the model (mean and standard deviation) were derived from 5560 normal and 51 Down syndrome‐affected pregnancies scanned during the first trimester in three different centers. Equations for calculating maternal background risk and median values were obtained from previous reports. The results were compared to two modalities using the log Gaussian model and software that uses the delta‐value model.ResultsThe distribution fitted the data well, and the parameters obtained in the study group for the log multiple of median model were a mean of 0 and a standard deviation of 0.12356 among normal pregnancies and a mean of 0.305312 and a standard deviation of 0.240337 among Down syndrome‐affected ones. The likelihood ratios obtained for the various combinations of fetal crown–rump lengths and nuchal translucency measurements were comparable to other modalities reported earlier.ConclusionsThe results of the current study provide useful tables for simple and accurate ‘bedside’ estimation of Down syndrome risk without the need for computerized software or complicated calculations. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Evolution of vertebrate forebrain development: how many different mechanisms?
Authors: FOLEY ANN C. , STERN CLAUDIO D. 
Published: March 2003

abstractOver the past 50 years and more, many models have been proposed to explain how the nervous system is initially induced and how it becomes subdivided into gross regions such as forebrain, midbrain, hindbrain and spinal cord. Among these models is the 2‐signal model of Nieuwkoop & Nigtevecht (1954), who suggested that an initial signal (‘activation’) from the organiser both neuralises and specifies the forebrain, while later signals (‘transformation’) from the same region progressively caudalise portions of this initial territory. An opposing idea emerged from the work of Otto Mangold (1933) and other members of the Spemann laboratory: 2 or more distinct organisers, emitting different signals, were proposed to be responsible for inducing the head, trunk and tail regions. Since then, evidence has accumulated that supports one or the other model, but it has been very difficult to distinguish between them. Recently, a considerable body of work from mouse embryos has been interpreted as favouring the latter model, and as suggesting that a ‘head organiser’, required for the induction of the forebrain, is spatially separate from the classic organiser (Hensen's node). An extraembryonic tissue, the ‘anterior visceral endoderm’ (AVE), was proposed to be the source of forebrain‐inducing signals. It is difficult to find tissues that are directly equivalent embryologically or functionally to the AVE in other vertebrates, which led some (e.g. Kessel, 1998) to propose that mammals have evolved a new way of patterning the head. We will present evidence from the chick embryo showing that the hypoblast is embryologically and functionally equivalent to the mouse AVE. Like the latter, the hypoblast also plays a role in head development. However, it does not act like a true organiser. It induces pre‐neural and pre‐forebrain markers, but only transiently. Further development of neural and forebrain phenotypes requires additional signals not provided by the hypoblast. In addition, the hypoblast plays a role in directing cell movements in the adjacent epiblast. These movements distance the future forebrain territory from the developing organiser (Hensen's node), and we suggest that this is a mechanism to protect the forebrain from caudalising signals from the node. These mechanisms are consistent with all the findings obtained from the mouse to date. We conclude that the mechanisms responsible for setting up the forebrain and more caudal regions of the nervous system are probably similar among different classes of higher vertebrates. Moreover, while reconciling the two main models, our findings provide stronger support for Nieuwkoop's ideas than for the concept of multiple organisers, each inducing a distinct region of the CNS.
Effect of angioplasty and grafting on porcine vascular nerves: a potential neurotropic role for endothelin‐1
Authors: DASHWOOD M. R. , ANGELINI G. D. , MEHTA D. , JEREMY J. Y. , MUENTER K. , KIRCHENGAST M. 
Published: March 2003

The most commonly performed procedure for treating coronary artery stenosis is percutaneous transluminal coronary angioplasty (PTCA) and, where the vessel lumen is severely narrowed, coronary artery bypass grafting (CABG). In PTCA, regions of atherosclerotic plaques are disrupted, and the vessel lumen increased by inflating a balloon catheter. In CABG an autologous saphenous vein into coronary artery interposition graft is performed in order to bypass occluded regions of epicardial coronary arteries. Both interventions cause varying degrees of vascular damage and the long‐term efficacy of these procedures is limited by a high incidence of neointimal formation and subsequent vascular restenosis (Bach et al. 1994; Bryan & Angelini, 1994).The endothelium‐derived constrictor peptide, endothelin‐1 (ET‐1) (Yanagisawa et al. 1988), also possesses mitogenic activity on vascular smooth muscle cells (Hirata et al. 1989) and has been suggested as playing a role in atherosclerosis (Dashwood et al. 1993; Zeiher et al. 1994) and intimal hyperplasia (Dashwood et al. 1993; Douglas et al. 1994).
DβH‐immunoreactive subepithelial nerves in the vas deferens of prostate cancer patients
Authors: JEN PHILLIP Y. P. , DIXON JOHN S. 
Published: March 2003

We recently reported the results of applying immunohistochemical methods to examine the distribution of neuropeptides and neurotransmitter synthesising enzymes in the autonomic nerve fibres of specimens of human vas deferens obtained at vasectomy (Jen et al. 1999). As anticipated from previous neurohistochemical and electron microscopic studies (Baumgarten et al. 1971), the majority of nerves supplying the muscle coat are noradrenergic in type as demonstrated by the presence of tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DbH) (Dixon et al. 1998), both of which are enzymes involved in the synthesis of noradrenaline.In addition to the profuse intramuscular plexus of nerves, a second nerve plexus occurs at the base of the epithelium lining the vas deferens. These subepithelial nerves are immunopositive for vesicular acetylcholine transporter (VAChT) and therefore cholinergic in type, presumably serving a secretomotor function (Jen et al. 1999). Our immunohistochemical studies have also shown the presence of neuropeptide Y (NPY) in most of these subepithelial nerves in the human vas deferens with minor populations containing vasoactive intestinal peptide (VIP) and nitric oxide synthase (NOS), an enzyme involved in the formation of nitric oxide.
The role of the notochord in vertebral column formation
Authors: FLEMING ANGELEEN , KEYNES ROGER J. , TANNAHILL DAVID 
Published: March 2003

abstractThe backbone or vertebral column is the defining feature of vertebrates and is clearly metameric. Given that vertebrae arise from segmented paraxial mesoderm in the embryo, this metamerism is not surprising. Fate mapping studies in a variety of species have shown that ventromedial sclerotome cells of the differentiated somite contribute to the developing vertebrae and ribs. Nevertheless, extensive studies in amniote embryos have produced conflicting data on exactly how embryonic segments relate to those of the adult. To date, much attention has focused on the derivatives of the somites, while relatively little is known about the contribution of other tissues to the formation of the vertebral column. In particular, while it is clear that signals from the notochord induce and maintain proliferation of the sclerotome, and later promote chondrogenesis, the role of the notochord in vertebral segmentation has been largely overlooked. Here, we review the established role of the notochord in vertebral development, and suggest an additional role for the notochord in the segmental patterning of the vertebral column.