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Villus Sampling (villus + sampling)
Kinds of Villus Sampling Selected AbstractsRecent advances in non-invasive prenatal DNA diagnosis through analysis of maternal bloodJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2007Akihiko Sekizawa Abstract Prenatal diagnosis of aneuploidy and single-gene disorders is usually performed by collecting fetal samples through amniocentesis or chorionic villus sampling. However, these invasive procedures are associated with some degree of risk to the fetus and/or mother. Therefore, in recent years, considerable effort has been made to develop non-invasive prenatal diagnostic procedures. One potential non-invasive approach involves analysis of cell-free fetal DNA in maternal plasma or serum. Another approach utilizes fetal cells within the maternal circulation as a source of fetal DNA. At the present time, fetal gender and fetal RhD blood type within RhD-negative pregnant women can be reliably determined through analysis of maternal plasma. Furthermore, genetic alterations can be diagnosed in the maternal plasma when the mother does not have the alterations. However, the diagnosis of maternally inherited genetic disease and aneuploidy is limited using this approach. Non-invasive prenatal diagnosis through examination of intact fetal cells circulating within maternal blood can be used to diagnose a full range of genetic disorders. Since only a limited number of fetal cells circulate within maternal blood, procedures to enrich the cells and enable single cell analysis with high sensitivity are required. Recently, separation methods, including a lectin-based method and autoimage analyzing, have been developed, which have improved the sensitivity of genetic analysis. This progress has supported the possibility of non-invasive prenatal diagnosis of genetic disorders. In the present article, we discuss recent advances in the field of non-invasive prenatal diagnosis. [source] Hemangioma in the newborn: increased incidence after chorionic villus samplingPRENATAL DIAGNOSIS, Issue 10 2010Constantijn G. Bauland Abstract Objectives This study was designed to compare the effects of transcervical chorionic villus sampling (CVS) and amniocentesis on the prevalence of hemangiomas of infancy. Methods This is a cohort study of 250 consecutive assessable transabdominal amniocentesis procedures and 250 consecutive assessable transcervical CVS procedures performed between January and September 2002. Parents were asked to fill out a questionnaire regarding the presence of any type of skin lesions. Based on the responses to the questionnaire, children were invited to undergo a physical examination to confirm hemangiomas. Results Questionnaires were returned in 78% of the CVS group (195/250) and in 72% of the amniocentesis group (180/250). Based on the responses in the questionnaire, 78 children in the CVS group and 42 in the amniocentesis group underwent a physical examination. One or more hemangiomas were present in 53 of 195 (27.2%) children in the CVS group versus 17 of 180 (9.4%) children in the amniocentesis group (odds ratio 3.6, 95% CI: 2.0,6.5). There was no difference in congenital abnormalities between the two groups. Conclusion Transcervical CVS is associated with a significantly increased prevalence of hemangiomas compared with amniocentesis. The clinical features of these hemangiomas do not differ from natural hemangiomas and complications of these hemangiomas are very rare. Copyright © 2010 John Wiley & Sons, Ltd. [source] MFM/geneticist view on prenatal management of twins,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2009Barbara M. O'Brien Abstract Twin pregnancies are associated with an increase in both fetal and maternal morbidity and mortality. Health care supervision is complex, increasingly requiring care from maternal-fetal medicine specialists. This review discusses optimal twin prenatal management, which includes recognizing increased twin pregnancy risks specific to twin-types; counseling families regarding fetal complications, ranging from prematurity to cerebral palsy; screening for aneuploidy and open neural tube defects; specific twin guidelines for diagnostic testing, including chorionic villus sampling and amniocentesis; and monitoring for maternal complications. © 2009 Wiley-Liss, Inc. [source] Is chorionic villus sampling associated with hypertensive disorders of pregnancy?PRENATAL DIAGNOSIS, Issue 1 2010Anthony O. Odibo Abstract Objective Our objective is to evaluate for potential associations between chorionic villus sampling (CVS) and hypertensive disorders of pregnancy. Methods Using our genetic database, we compared the rates of hypertensive disorders between women who underwent CVS at 10,13 and 6/7 weeks with those seen for other indications at similar gestational ages who had no invasive procedure. Only singleton and euploid pregnancies were included. Statistical methods including univariable and multivariable logistic regression, supplemented by stratified analyses were used for comparisons. Results Among 11 012 pregnant women seen between 1990 and 2006 in our center and meeting the inclusion criteria, information on hypertensive disorders of pregnancy were available in 9386, and 9098 met the inclusion criteria. The overall incidence of hypertensive disorders was 421/9098 (4.6%), with 138/5096 (2.7%) in the CVS group and 283/4002 (7.1%) in the control group [adjusted odds ratio (adjOR) 0.47, 95% confidence interval (CI), 0.38,0.59]. Similar findings were seen on stratified analyses for gestational age of procedure and the type or severity of hypertensive disorder, and other potential confounders. Conclusion The rate of hypertensive disorders of pregnancy is significantly lower in women having CVS compared with the control group. Placental disruption from CVS is not associated with preeclampsia or gestational hypertension. Copyright © 2009 John Wiley & Sons, Ltd. [source] Noninvasive prenatal diagnosis of fetal blood group phenotypes: current practice and future prospectsPRENATAL DIAGNOSIS, Issue 2 2009Geoff Daniels Abstract Fetuses of women with alloantibodies to RhD (D) are at risk from hemolytic disease of the fetus and newborn, but only if the fetal red cells are D-positive. In such pregnancies, it is beneficial to determine fetal D type, as this will affect the management of the pregnancy. It is possible to predict, with a high level of accuracy, fetal blood group phenotypes from genotyping tests on fetal DNA. The best source is the small quantity of fetal DNA in the blood of pregnant women, as this avoids the requirement for invasive procedures of amniocentesis or chorionic villus sampling (CVS). Many laboratories worldwide now provide noninvasive fetal D genotyping as a routine service for alloimmunized women, and some also test for c, E, C and K. In many countries, anti-D immunoglobulin injections are offered to D-negative pregnant women, to reduce the chances of prenatal immunization, even though up to 40% of these women will have a D-negative fetus. High-throughput, noninvasive fetal D genotyping technologies are being developed so that unnecessary treatment of pregnant women can be avoided. Trials suggest that fetal D typing of all D-negative pregnant women is feasible and should become common practice in the near future. Copyright © 2008 John Wiley & Sons, Ltd. [source] Molecular prenatal diagnosis for hereditary distal arthrogryposis type 2BPRENATAL DIAGNOSIS, Issue 5 2007Miao Jiang Abstract Autosomal dominant distal arthrogryposes (DAs) are a group of muscle diseases characterized by congenital contractures of the limbs. Currently, prenatal diagnosis of DAs depends upon ultrasound examination during late gestation. Recently, five genes encoding fast switch proteins located at 9p13.2, 11p15.5 and 17q13.1 were identified. These included TPM2, TNNI2/TNNT3, and MYH3/MYH8. Last year, we discovered a novel heterozygous mutation c.523_525delAAG (p.K175del) in the TNNI2 gene, which encodes the isoform of troponinI, in a seven-generation Chinese family affected with distal arthrogryposis type 2B (DA2B). Here, we report the molecular prenatal diagnosis of 3 high-risk fetuses of two women in the family by two-point linkage inferential analysis and deletion detection of the TNNI2 gene with chorionic villus sampling (CVS) or amniocentesis. To our knowledge, this is the first description of molecular prenatal diagnosis for DAs. Copyright © 2007 John Wiley & Sons, Ltd. [source] Maternal age-specific fetal loss rates in Down syndrome pregnanciesPRENATAL DIAGNOSIS, Issue 6 2006George M. Savva Abstract Objectives Pregnancies affected by Down syndrome (DS) have a greater risk of spontaneous fetal loss than those that are unaffected. In this article, we investigate the relationship between maternal age and the risk of spontaneous fetal loss in DS pregnancies. Methods Fetal loss at different maternal ages were estimated by survival analysis using follow-up of 5177 prenatally diagnosed cases. The maternal age effect on loss rate was subsequently confirmed by a re-analysis of published comparisons of the maternal age-specific prevalence of DS at different gestational ages. Results The average fetal loss rate between the time of chorionic villus sampling (CVS) and term was 32% (95% CI: 26,38), increasing from 23% (95% CI: 16,31) for women aged 25 to 44% (33,56) for women aged 45. The average fetal loss rate between the time of amniocentesis and term was 25% (21,31), increasing from 19% (14,27) to 33% (26,45) across the same age range. Conclusion The fetal loss rate in DS pregnancies increases with maternal age, and this has consequences when estimating the live birth prevalence of DS in the presence of prenatal diagnosis and termination, and when assessing the performance of prenatal screening techniques. Copyright © 2006 John Wiley & Sons, Ltd. [source] (Potential) false-negative diagnoses in chorionic villi and a review of the literaturePRENATAL DIAGNOSIS, Issue 5 2006Cardi van den Berg Abstract Objectives To assess the incidence of (potential) false-negative findings of cytogenetic diagnosis in STC-villi and/or LTC-villi and to determine the best strategy for karyotyping chorionic villi in order to avoid false-negative results. Methods 2476 chorionic villus samples were received for prenatal cytogenetic investigations. Karyotyping was routinely performed on STC- and LTC-villi preparations by G-banding. Fluorescence in situ hybridization (FISH) analyses were performed in addition to standard chromosome analysis when necessary. Sometimes follow-up investigations like amniocentesis were performed before a definite prenatal cytogenetic result could be reported. Results In 2389/2476 (96.5%) of the cases, both STC- and LTC-villi were investigated. Normal STC- with abnormal LTC-villi results and finally an abnormal fetal karyotype were detected in ten cases (10/2389; 0.42%); in 9/10 of the cases the indication was fetal ultrasound abnormalities. Normal STC- and LTC-villi and finally an abnormal fetal karyotype were detected in two cases (2/2389; 0.08%). Conclusion The most reliable technique for prenatal diagnosis after chorionic villus sampling (CVS) is the combination of the analysis of both STC- and LTC-villi to reduce the incidence of false-negative findings to a minimum. In the case of fetal ultrasound abnormalities with a small amount of villi available, the investigation of LTC-villi is recommended over that of STC-villi. Copyright © 2006 John Wiley & Sons, Ltd. [source] Fetomaternal hemorrhage in relation to chorionic villus sampling revisitedPRENATAL DIAGNOSIS, Issue 3 2006Denise M. Pelikan Abstract Objective To investigate whether chorionic villus sampling (CVS) results in a proportional increase of alpha-fetoprotein (AFP) and fetal red cells in maternal blood. Methods Blood samples were collected before and after CVS. The AFP concentration was measured and supervised automated microscopy of Kleihauer,Betke slides was applied to quantify fetal red cells. Results AFP analysis was performed in 53 paired samples and automated microscopic scanning in 59 paired samples. Median AFP concentrations before and after CVS were 12.0 µg/L (range 6.4,36.4) and 18.7 µg/L (range 8.2,668.9), respectively, indicating a significant increase (p < 0.0001). Median numbers of fetal red cells detected before and after CVS were 0 (range 0,36) and 0 (range 0,31), respectively. No significant increase of fetal cells was observed (p = 0.72). The delta (,) fetal red cells and the , AFP correlated poorly (, = ,0.22, p = 0.11). The amount of villi correlated moderately with the , AFP (, = 0.32, p = 0.02) and did not correlate with the , fetal red cells (, = ,0.11, p = 0.43). Conclusions Although the AFP concentration after CVS increased, no increase of fetal red cells was detected. These findings suggest that CVS results in a leakage of proteins due to placental tissue damage, rather than increased trafficking of fetal cells. Copyright © 2006 John Wiley & Sons, Ltd. [source] Prenatal diagnosis of citrullinemia and argininosuccinic aciduria: evidence for a transmission ratio distortion in citrullinemiaPRENATAL DIAGNOSIS, Issue 3 2006Wim J. Kleijer Abstract Background In the course of 25 years, we have experienced a high rate of affected fetuses in the prenatal diagnosis of citrullinemia. Methods and Results Ninety-one pregnancies at 1 in 4 risk were tested; 36 were diagnosed as affected (39.5%; P = 0.0015). The high rate of positive diagnoses was found both after chorionic villus sampling (24/68 = 35.3%) and amniocentesis (12/23 = 52.2%) despite the completely different and independent techniques used. Using exactly the same (indirect) enzyme assay for argininosuccinic aciduria on chorionic villi and a similar method on amniotic fluid, the expected rate of affected fetuses was found: 13/53 = 24.5%. Technical and genetic causes for the unexpected results were excluded by confirmatory studies performed on independent fetal material, which was available for 27 of the 36 fetuses affected with citrullinemia. Biochemical confirmation was obtained in the 27 cases, whereas in 18 fetuses homozygosity or compound heterozygosity for disease-causing mutations were retrospectively demonstrated in the stored fetal cells. Conclusion The results suggest the occurrence of preferential transmission of the mutant allele. An explanation for this phenomenon may be found in a protective role of argininosuccinic acid synthetase deficiency in mutant sperm cells against the possibly detrimental or apoptotic effect of nitric oxide produced normally from arginine by nitric oxide synthase. Copyright © 2006 John Wiley & Sons, Ltd. [source] How painful are amniocentesis and chorionic villus sampling?,PRENATAL DIAGNOSIS, Issue 1 2006Akos Csaba Abstract Objectives To compare the levels of pain and anxiety associated with amniocentesis (AC), transabdominal chorionic villus sampling (TA-CVS), and transcervical chorionic villus sampling (TC-CVS). Methods We prospectively administered a questionnaire about pain and anxiety to 124 women undergoing AC, 40 undergoing TA-CVS, and 24 undergoing TC-CVS for singleton pregnancies. The level of pain was quantified with numerical and pictorial scales and the degree of anxiety was quantified with a numerical scale (0,100 in increments of 10). Results The mean pain score for TA-CVS, 41.4 ± 18.1, was significantly higher than that for TC-CVS, 26.4 ± 25.3, p = 0.008. The mean pain score for AC, 35.1 ± 27.6, was intermediate. A higher degree of anxiety was associated with younger maternal age and nulliparity. A higher degree of anxiety was associated with a higher level of pain. Conclusion In general, each procedure is associated with a tolerable amount of pain. TA-CVS appears to be the most painful procedure while TC-CVS appears to be the least painful procedure. In certain groups of patients, the procedures may be associated with higher levels of pain and/or anxiety. Copyright © 2006 John Wiley & Sons, Ltd. [source] Prenatal diagnosis of sickle syndromes in India: dilemmas in counsellingPRENATAL DIAGNOSIS, Issue 5 2005Roshan Colah Abstract Objectives The sickle gene is prevalent in the scheduled caste and tribal populations in India. The clinical presentation of sickle cell disease is extremely variable, and there are no neonatal screening programmes. This is the first report on prenatal diagnosis of sickle syndromes in 85 couples at risk (sickle cell anemia-69; sickle thalassemia-16) from different regions in India. Most of the couples were from a low socioeconomic group and their decisions were entirely dependent on the local counselling given. We have evaluated the acceptability of prenatal diagnosis and the dilemmas faced in counselling these families. Methods Chorion villus sampling was done in the first trimester and DNA analysis using reverse dot blot hybridization or restriction enzyme digestion with Dde1 in 65 cases. Cordocentesis was done in the second trimester and fetal blood analyses by automated HPLC in 20 cases who came late. Results 32.9% of couples came prospectively for diagnosis. 23.5% of fetuses were affected (sickle cell anemia-18, sickle thalassemia-2). The ,-thalassemia mutation in both cases was IVS 1,5(G- > C). All the couples with an unfavourable diagnosis opted for termination of pregnancy. Conclusion Sickle cell anemia has a relatively benign clinical course in some tribal groups in India. This raises a dilemma whether we are justified in advising prenatal diagnosis in all such cases. Copyright © 2005 John Wiley & Sons, Ltd. [source] Prenatal diagnostic procedures used in pregnancies with congenital malformations in 14 regions of EuropePRENATAL DIAGNOSIS, Issue 11 2004Ester Garne Abstract Objective To investigate outcomes of ultrasound investigations (US) and invasive diagnostic procedures in cases of congenital malformations (CM), and to compare the use of invasive prenatal test techniques (amniocentesis (AC) versus chorionic villus sampling (CVS)) among European populations. Design Analysis of data from population-based registries of CM. Subjects 25 400 cases of CM recorded by 14 EUROCAT registries covering a total population of 1 013 352 births 1995,99. Results US were performed in 91% of cases, and positively detected CM in 35% of cases. AC was performed in 24% of the cases and CVS in 3% of cases. Thirty-eight percent of invasive tests gave positive results. Fifty-two percent of cases with maternal age , 35 years had an invasive test performed compared to 20% of cases with younger mothers. Considerable variation was found between registries in the uptake rate of invasive tests in cases with older maternal age and on the use of invasive tests with only four regions employing CVS techniques in at least a third of the cases having invasive tests. For chromosomal anomalies US gave positive results in 46% of cases with maternal age < 35 years with US performed and in 36% of cases with maternal age , 35 years with US performed. Conclusion Prenatal US was performed in 91% of all pregnancies with CM but the test was only positive in a third of the cases. There was large regional variation in the uptake rate of invasive tests with maternal age of 35 years or more. For every CVS carried out there were nine AC tests. US is an important tool in the prenatal diagnosis of chromosomal anomalies in Europe. Copyright © 2004 John Wiley & Sons, Ltd. [source] Prenatal diagnosis of tetrasomy 9p with Dandy,Walker malformationPRENATAL DIAGNOSIS, Issue 8 2004Markus Hengstschläger Abstract Objectives To add to the knowledge of chromosomal abnormalities associated with Dandy,Walker malformation. Methods Molecular cytogenetic analyses of a chorionic villus sampling and of an amniocentesis of a fetus with Dandy,Walker malformation and abnormal somatic development. Results All cells examined showed a 47, XY, +idic(9p)(pter,q12::q12,pter) de novo karyotype. This report describes the fourth case of a tetrasomy 9p associated with Dandy,Walker malformation Conclusions This case, together with the three previously reported cases of an association with a tetrasomy 9p, indicate that this chromosomal aberration should be looked for when Dandy,Walker malformation is detected via prenatal ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd. [source] Chorionic villus sampling (CVS) and fluorescence in situ hybridization (FISH) for a rapid first-trimester prenatal diagnosisPRENATAL DIAGNOSIS, Issue 4 2004Carole Goumy Abstract Objectives Early diagnosis of unbalanced chromosomal abnormalities can be crucial in minimizing the trauma caused by an elective abortion. Chorionic villus sampling (CVS) can be performed from 9 weeks of gestation. However, two major problems are encountered in fetal karyotyping using cultured cells from chorionic villi: the relatively slow growth of these cells in culture, which delays the diagnosis, and the occurrence of maternal cell contamination (MCC). With FISH, a result can be obtained within 24 h, and, as no cell culturing is involved, the problem of MCC is minimized. Methods Thirty-two women undergoing CVS between 9 and 12 weeks of gestation were offered FISH analysis in addition to the standard chromosome analysis. Results FISH was informative in all of the cases tested. Eleven aneuploidies were detected in cases of hygroma or abnormal nuchal translucency and two out of four fetuses from parental translocation were unbalanced. The decision to perform early termination of these chromosomally abnormal pregnancies was based on FISH results and ultrasound abnormalities, without waiting for karyotype results. Conclusion The present study confirms that the association of FISH and CVS allows a rapid and early prenatal diagnosis, and emphasizes that this association is of great benefit in cases of known parental balanced translocation or when hygroma is detected by ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd. [source] Novel mutation and prenatal sonographic findings of glutaric aciduria (type I) in two Taiwanese familiesPRENATAL DIAGNOSIS, Issue 8 2002S. K. Lin Abstract Glutaric aciduria type I (GA I) is an autosomal recessively inherited inborn error with a defect of the enzyme glutaryl-CoA dehydrogenase (GCDH), which has never been diagnosed prenatally in Taiwanese patients. We present the prenatal sonographic findings and mutational analysis data of three children in two Taiwanese families. One patient from each family was diagnosed postnatally due to macrocephaly and neurological deterioration at 4,months and 10,months, respectively. The third child, sister of the first patient, was diagnosed prenatally at 11,weeks' gestation through chorionic villus sampling (CVS). Molecular analysis revealed that the fetus and child in Family 1 were homozygous for a common mutation, IVS10 -2A>C, which has not been reported in the Caucasian population. The patient in Family 2 was a compound heterozygote for IVS10 -2A>C and a novel mutation 749T>C (L238P). After genetic counseling, the couple decided to continue the second pregnancy. However, dilatation of quadrigeminal cistern (QC) and suspicious macrocephaly were noted at 30,weeks. Progressive dilatation of the QC associated with macrocephaly, fronto-temporal atrophy and wide space of perisylvian fissure were found in the follow-up scans. The affected girl was delivered at 37,weeks' gestation by cesarean section. Postnatal magnetic resonance imaging (MRI) studies confirmed the prenatal sonographic findings. With prenatal sonographic findings and mutational analysis presented in the present cases, the feasibility of prenatal diagnosis of GA I in high-risk pregnancy can not be overlooked. Copyright © 2002 John Wiley & Sons, Ltd. [source] Transcervical chorionic villus sampling in multiple pregnancies using a biopsy forcepsPRENATAL DIAGNOSIS, Issue 3 2002Gemma Casals Abstract Objective The aim of this study was to assess the effectiveness and safety of chorionic villus sampling (CVS) performed in multiple pregnancies by means of a transcervical biopsy forceps. Methods The study included CVS performed from January 1990 to March 2000 in our Unit. The results were analysed in two consecutive periods, period A (1990,1994) and period B (1995,2000), in an attempt to assess the effect of increasing experience. Results Seventy-five samplings were performed in 39 multiple pregnancies, 38 twin sets and one triplet. A cytogenetic report was obtained in 73% of cases in period A and in 98% in period B. An abnormal karyotype was observed in 11 samples. The need for subsequent amniocentesis decreased from 38% in period A to 10% in period B. The spontaneous fetal loss rate in chromosomally and structurally normal fetuses before the 20th week decreased from 8.7% in period A to 3.3% in period B. The fetal loss rate after the 20th week was 3.3% in period B and none in period A. It must be noted that in three out of the four cases of fetal loss an amniocentesis was needed after CVS. Conclusion Our results suggest that effectiveness and safety improved with increasing experience. Transcervical chorionic villus sampling allows an earlier prenatal genetic diagnosis in multiple pregnancies and this may be particularly relevant for a safer selective termination when chosen by parents if one of the fetuses has an abnormal karyotype. Copyright © 2002 John Wiley & Sons, Ltd. [source] Prenatal diagnosis of trisomy 20 by chorionic villus sampling (CVS): a case report with long-term outcomePRENATAL DIAGNOSIS, Issue 13 2001Nancy Steinberg Warren Abstract A case of prenatally diagnosed non-mosaic trisomy 20 in cells cultured from a chorionic villus sample (CVS)is presented. The term placental karyotype was also non-mosaic trisomy 20. The karyotype of thenewborn was 46,XY/47,XY,+20 in foreskin cultures and in a second skin culture; blood lymphocyte culture was 46,XY. Aside from diffuse, hypopigmentary swirls along the lines of Blaschko observed on hisextremities and trunk, referred to as hypomelanosis of Ito, the patient is clinically normal at 8¾ years ofage. In addition, he is one of the oldest reported cases of mosaic trisomy 20 confirmed after birth forwhich the clinical outcome has been monitored. This case demonstrates that these trisomy 20 findings are compatible with normal psychomotor development and phenotype. Copyright © 2001 John Wiley & Sons, Ltd. [source] The selective use of rapid aneuploidy screening in prenatal diagnosisAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2009Jan E. DICKINSON Aims: To evaluate the diagnostic utility and costing of the selective use of rapid aneuploidy screening (RAS) for chorion villus sampling (CVS) and amniocentesis specimens. Methods: CVS and amniocenteses performed between 2000 and 2006 were identified. Cases were subdivided into two groups: (i) RAS in addition to long-term culture and (ii) long-term chromosome culture alone. The frequency of RAS, the proportion of abnormal results and the cytogenetic costings were reviewed. Results: A total of 3315 procedures were performed: 730 CVS and 2585 amniocenteses. An abnormal karyotype culture was present in 366 of 3315 (11%). For CVS an abnormal culture was present in 164 (22.5%). RAS (short-term culture/direct preparation) was selectively used in 399 cases (54.6%) with an abnormal result in 128 (32% of RAS). For amniocentesis, 206 chromosome abnormalities were present (8.0% of specimens). RAS (interphase FISH) was selectively used in 580 amniocenteses (22.4%). FISH was requested in 95 (66.4%) of the 143 abnormal cases potentially detectable with standard probes. There was a progressive increase in utilisation of RAS for amniocentesis (8.9% in 2000 to 43.3% of cases in 2006, P < 0.001). CVS RAS was stable. This liberalisation resulted in a fourfold increase in expenditure for FISH and cost/abnormality detected ($A970 per abnormal result in 2000 to $A4015 per abnormal result in 2006). Conclusion: The selective use of prenatal RAS results in a reasonably high detection rate for chromosomal anomalies. Liberalisation of RAS, however, is an expensive cytogenetic model. An approach based on some predictive level of risk combined with resource funding levels may be a more pragmatic approach. [source] Synthesis of Evidence from Epidemiological Studies with Interval-Censored Exposure Due to GroupingBIOMETRICS, Issue 3 2001Richard J. Cook Summary. We describe a method for assessing dose,response effects from a series of case,control and cohort studies in which the exposure information is interval censored. The interval censoring of the exposure variable is dealt with through the use of retrospective models in which the exposure is treated as a multinomial response and disease status as a binary covariate. Polychotomous logistic regression models are adopted in which the dose-response relationship between exposure and disease may be modeled in a discrete or continuous fashion. Partial conditioning is possible to eliminate some of the nuisance parameters. The methods are applied to the motivating study of the relationship between chorionic villus sampling and the occurrence of terminal transverse limb reduction. [source] Fetal RHD genotyping in maternal serum during the first trimester of pregnancyBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002Jean-Marc Costa Summary., Fetal RHD genotype determination is useful in the management of sensitized RhD-negative pregnant women. It can be ascertained early during pregnancy by chorionic villus sampling (CVS) or amniocentesis. However, these procedures are invasive, resulting both in an increased risk of fetal loss and in an increased severity of immunization due to fetomaternal haemorrhage. A reliable determination of RHD genotype by fetal DNA analysis in maternal serum during the first trimester of pregnancy is reported in this study. One hundred and six sera from RhD-negative pregnant women were obtained during the first trimester of pregnancy. These sera were tested for the presence of RHD gene using a new real-time polymerase chain reaction assay and the results compared with those obtained later in pregnancy on amniotic fluid cells and by RHD serology of the new-born. All sera from women carrying a RhD-positive fetus (n = 62) gave positive results for RHD gene detection and sera from women carrying a RhD-negative fetus (n = 40) were negative. The high level of accuracy of fetal RHD genotyping obtained in this study could enable this technique to be offered on a routine basis for the management of RhD-negative patients during the first trimester of pregnancy. [source] | |||||||||||||