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Prenatal Screening (prenatal + screening)

Distribution by Scientific Domains

Life Sciences	77%
Medical Sciences	22%

Selected Abstracts

Descriptive epidemiology of Down's syndrome in Estonia

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 6 2006
Tiia Reimand
Summary The aim of the study was to investigate the livebirth prevalence of Down's syndrome (DS) in Estonia during the past 14 years, create a DS database and observe the effectiveness of prenatal screening. This is a population-based descriptive study. The study subjects were children with DS diagnosis born between the years 1990 and 2003. We collected data from genetic centres in Estonia, from the databases of DS support groups, from institutions for disabled children and from the registers of family doctors/paediatricians. Prenatal screening for chromosomal anomalies for women aged ,35 years was started in Estonia in 1995. Therefore, we divided the DS children into two groups: 112 born between 1990 and 1994 comprise group I, and 127 born between 1995 and 2003 comprise group II. Group II was further divided into two subgroups: IIa, from 1995 to 1998, when screening of advanced maternal age (,35 years) commenced, and IIb, from 1999 to 2003, when screening of second trimester maternal serum for younger women commenced. Prenatally, 68 cases of DS were diagnosed between 1995 and 2003 in the whole of Estonia, and all of these pregnancies were terminated. This represents 34.9% of all delivered and prenatally detected DS cases from this period. The overall livebirth prevalence was 1.17 per 1000 livebirths. The livebirth prevalence in group I was 1.25 and in group II was 1.09 per 1000 livebirths. The second trimester maternal serum screening with advanced maternal age screening was more effective than advanced maternal age screening alone. The livebirth prevalence in group IIa was 1.22 and in group IIb 0.99 per 1000 livebirths. Overall, regular trisomy was found in 90.4%, translocation in 6.3% and mosaicism in 2.9%. The overall male to female sex ratio of DS was 1.09. [source]

Prenatal screening for serious congenital heart defects using nuchal translucency: a meta-analysis

PRENATAL DIAGNOSIS, Issue 12 2008
Nicholas J. Wald
Abstract Objectives To assess the performance of nuchal translucency (NT) measurements in screening for congenital heart defects (CHD) which would benefit from prenatal detection. Methods A literature search was conducted of studies published prior to August 2007 of CHD and NT measurements in fetuses without chromosome defects. From this, data on 159 pregnancies were obtained. Fetuses with CHD that would benefit from prenatal detection were identified and their NT measurements were compared with NT measurements in 29 776 unaffected fetuses without Down syndrome from the Serum Urine and Ultrasound Screening Study (SURUSS) trial to determine the screening performance of NT measurements. Results In all 67 fetuses with CHD were identified as potentially likely to benefit from prenatal detection. Using NT measurements, the estimated detection rate (DR) for a 5% false-positive rate (FPR) was 52% (95% CI: 42,71). Conclusion Prenatal screening for CHD using NT measurements is likely to be effective, and given that NT measurement is already in place as part of prenatal screening for Down syndrome; this is an ideal time to set up demonstration projects to validate these results. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Prenatal screening and diagnosis of congenital toxoplasmosis: a review of safety issues and psychological consequences for women who undergo screening

PRENATAL DIAGNOSIS, Issue 5 2007
Babak Khoshnood
Abstract As part of the EUROTOXO initiative, this review focuses on the potential risks associated with prenatal testing for congenital toxoplasmosis. We first review the evidence on the risks of adverse events associated with amniocentesis, which is required for definitive diagnosis of toxoplasmosis infection in the fetus, and for which the most important risk is fetal loss. To date, there has been only one randomized trial to document risks associated with amniocentesis. This trial, which was conducted in 1986, reported a procedure-related rate of fetal loss of 1.0% (95% CI, 0.3,1.5). However, evidence from available controlled studies suggests that the pregnancy loss associated with mid-trimester amniocentesis may be lower. Potential psychological consequences of prenatal testing for congenital toxoplasmosis include parental anxiety due to false positive results and uncertainties related to prognosis of children with a prenatal diagnosis of congenital toxoplasmosis. Parental anxiety may be particularly important in screening strategies that include more frequent screenings, which may in turn entail substantial, and at times unnecessary, anxiety or other negative consequences for women and their families. These negative psychological outcomes should be balanced against the benefits of testing, which can allow women to make an informed choice regarding the pregnancy. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Prenatal screening and diagnosis,An introduction,

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 1 2007
Susan Gross M.D.
First page of article [source]

Accepting or declining the offer of prenatal screening for congenital defects: test uptake and women's reasons

PRENATAL DIAGNOSIS, Issue 1 2005
Matthijs van den Berg
Abstract Objectives Prenatal screening for Down syndrome has become standard practice in many western countries. In the Netherlands, however, prenatal screening tests for congenital defects are not offered routinely. The present study aims to assess test uptake in a large, unselected population of pregnant women, and to give more insight into the decision for or against prenatal screening through nuchal translucency measurement or maternal serum screening. Patients and Methods The study is part of a randomized controlled trial with two groups, each being offered a different prenatal screening test, and a control group. Pregnant women received postal questionnaires at three stages of their pregnancy. Results Of the women being offered the nuchal translucency measurement or the second trimester maternal serum test, 53 and 38% respectively accepted the test offer. The main reasons for accepting were ,gaining knowledge about the health of the foetus/curiosity' (50%), ,favourable characteristics of the screening test' (18%), and ,increased risk of having a child with DS' (15%). The main reasons for declining were ,unfavourable characteristics of the screening test' (42%), ,not applicable/not necessary' (35%), ,anxiety/uncertainty' (36%), ,adverse characteristics of the invasive tests' (32%), and ,being against abortion' (15%). Discussion The uptake of prenatal screening was relatively low, and different distributions of reasons were reported, compared to other studies. These differences may be due to the specific Dutch situation in which prenatal screening is not part of standard prenatal care. The question arises as to whether informed decision-making would be reduced if prenatal screening became routinised. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Prenatal screening for Down syndrome: the problem of recurrent false-positives

PRENATAL DIAGNOSIS, Issue 5 2004
Nicholas J. Wald
Abstract Objectives It has been reported that, in prenatal screening programmes for Down syndrome, women who have false-positive results in one pregnancy have an increased risk of a false-positive result in a subsequent pregnancy. We examined the effect of this in the screening programme conducted from the Wolfson Institute of Preventive Medicine with a view to determining the magnitude of the effect, and to describe a method of avoiding the problem. Methods Six thousand four hundred and forty-eight women were identified who had had two singleton pregnancies without Down syndrome in the screening programme based at the Wolfson Institute of Preventive Medicine, in which both pregnancies were screened using a Quadruple test (maternal age with alphafetoprotein (AFP), unconjugated oestriol (uE3), total or free ,-human chorionic gonadotrophin (hCG) and either free ,-hCG or inhibin-A as the fourth serum marker). Results Among women who had a false-positive result in their initial pregnancy, the false-positive rate in the subsequent pregnancy was high: 20% (46/229), about three times higher than both the overall observed false-positive rate (6.6%), and the expected false-positive rate, in subsequent pregnancies that were false,positive in their initial pregnancy (7.5%) (p < 0.001). This arises because serum marker levels in one pregnancy are associated with the levels in a subsequent pregnancy. Using the slope (the regression coefficient b) of each marker level in a subsequent pregnancy regressed on the value in the first pregnancy, it is possible to adjust all marker values in a subsequent pregnancy to allow for the higher-than-expected false-positive rate. This can be done by dividing the observed MoM value for each marker by the ,expected' MoM, which is the MoM value in a previous pregnancy raised to the power b. Conclusions If a woman has had a false-positive result in one pregnancy, she is much more likely to have a false-positive screening result in a subsequent pregnancy than women in general. The problem can be avoided by adjusting the serum markers in all women who have been screened in a previous pregnancy and who have not had a previous pregnancy with Down syndrome. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Uptake of prenatal screening for chromosomal anomalies: impact of test results in a previous pregnancy

PRENATAL DIAGNOSIS, Issue 13 2002
Kevin Spencer
Abstract Aim To assess whether the uptake of prenatal screening for trisomy 21 in a subsequent pregnancy is influenced by being classified in the ,increased risk' or ,not at increased risk' group in the first pregnancy. Setting District General Hospital Maternity Unit. Methods Amongst a group of women attending for maternity care at this hospital, the maternity records were examined to find women having at least two pregnancies. Any prenatal screening record for each pregnancy was retrieved from the prenatal screening database. Prenatal screening for trisomy 21 was by a combination of maternal serum ,-fetoprotein (AFP) and free ,-human chorionic gonadotrophin (,-hCG) in the second trimester and by maternal serum free ,-hCG and pregnancy-associated plasma protein-A (PAPP-A) and fetal nuchal translucency (NT) thickness in the first trimester. Women were stratified according to their trisomy 21 risk into an ,increased risk' group (1: <250 in the second trimester and 1: <300 in the first trimester) or ,not at increased risk' group based on their first pregnancy. In a second pregnancy, the records were examined to see if the mother accepted prenatal screening in the second pregnancy. The rate of acceptance of screening in a subsequent pregnancy, depending on whether ,at increased risk' or ,not at increased risk' in the first pregnancy, was examined using chi square tests. Results In the second trimester study, 4601 women were identified with two pregnancies during the study period. Of these, 4559 women had prenatal screening in a subsequent pregnancy. Initially, 273 women were identified in the high-risk group, and of these 252 (92.3%) elected to have prenatal screening in a subsequent pregnancy. This compared with 4307 of 4328 (99.5%) women in the low-risk group. In the first trimester study, 1077 women were identified with two pregnancies during the study period. Of these, 1072 had prenatal screening in a subsequent pregnancy. Initially, 60 women were identified in the high-risk group, and of these 56 (93.3%) elected to have prenatal screening in a subsequent pregnancy. This compared with 1016 of 1017 (99.9%) in the low-risk group. Statistically, there was no difference between the rate of declining prenatal screening in a second pregnancy amongst those in the high-risk group in a first pregnancy or those in the low-risk group (p = 0.429 for second trimester screening and p = 0.794 for first trimester screening). Similarly, no difference could be demonstrated between rates when screening in the first or second trimester (p = 0.961) for those in the high-risk group. Conclusion Despite the understandable anxiety associated with being identified in the high-risk group (as a false positive finding) in a previous pregnancy, this did not seem to deter women from accepting prenatal screening in a subsequent pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Brief screening questionnaires to identify problem drinking during pregnancy: a systematic review

ADDICTION, Issue 4 2010
Ethel Burns
ABSTRACT Aims Although prenatal screening for problem drinking during pregnancy has been recommended, guidance on screening instruments is lacking. We investigated the sensitivity, specificity and predictive value of brief alcohol screening questionnaires to identify problem drinking in pregnant women. Methods Electronic databases from their inception to June 2008 were searched, as well as reference lists of eligible papers and related review papers. We sought cohort or cross-sectional studies that compared one or more brief alcohol screening questionnaire(s) with reference criteria obtained using structured interviews to detect ,at-risk' drinking, alcohol abuse or dependency in pregnant women receiving prenatal care. Results Five studies (6724 participants) were included. In total, seven instruments were evaluated: TWEAK (Tolerance, Worried, Eye-opener, Amnesia, Kut down), T-ACE [Take (number of drinks), Annoyed, Cut down, Eye-opener], CAGE (Cut down, Annoyed, Guilt, Eye-opener], NET (Normal drinker, Eye-opener, Tolerance), AUDIT (Alcohol Use Disorder Identification Test), AUDIT-C (AUDIT-consumption) and SMAST (Short Michigan Alcohol Screening Test). Study quality was generally good, but lack of blinding was a common weakness. For risk drinking sensitivity was highest for T-ACE (69-88%), TWEAK (71,91%) and AUDIT-C (95%), with high specificity (71,89%, 73,83% and 85%, respectively). CAGE and SMAST performed poorly. Sensitivity of AUDIT-C at score ,3 was high for past year alcohol dependence (100%) or alcohol use disorder (96%) with moderate specificity (71% each). For life-time alcohol dependency the AUDIT at score ,8 performed poorly. Conclusion T-ACE, TWEAK and AUDIT-C show promise for screening for risk drinking, and AUDIT-C may also be useful for identifying alcohol dependency or abuse. However, their performance as stand-alone tools is uncertain, and further evaluation of questionnaires for prenatal alcohol use is warranted. [source]

Case report of HbC/,0 -thalassemia from India

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2007
S. KUMAR
Summary This 22-year-old women presented to the ante-natal clinic of this hospital for prenatal screening for , -thalassemia. Cation exchange high performance liquid chromatography (HPLC) using ,Beta Thalassemia Short Program' on Bio-Rad ,Variant' system revealed HbC value of 81.6%. The CBC showed microcytic hypochromic anemia. The HPLC and CBC suggested the possibility of compound heterozygote state for HbC/, -thalassemia. The alkali and acid electrophoresis findings were consistent with the above diagnosis. The DNA analysis confirmed compound heterozygote state for HbC/,0 -thalassemia (Fr 8/9 mutation). The studies on the parents showed that mother was a compound heterozygote for HbDPunjab and HbC while father had , -thalassemia trait. To the best of our knowledge, this is the first confirmed report of HbC from India. The paper discusses the hematological findings in this subject and her mother (a compound heterozygote for HbDPunjab and HbC). [source]

Exploring the perspective of midwives involved in offering serum screening for Down's syndrome in Northern Ireland

JOURNAL OF CLINICAL NURSING, Issue 20 2009
Jennifer McNeill
Aims., To explore the perspective of midwives offering serum screening for Down's syndrome. Background., Previous literature has indicated that the offer and discussion of prenatal serum screening tests with women is complex, and health professionals may influence women's decisions to accept or decline screening. Midwives are usually the key professional to offer serum screening for Down's syndrome in the UK but their perspective is relatively neglected in the literature. Design., An explorative qualitative interview study with 15 midwives employed in a maternity unit in Northern Ireland involved in offering prenatal screening to pregnant women. Data were collected from 1 July 2005,31 October 2005. Methods., A focused ethnographic approach was used to explore the perspective of midwives. Results., Midwives reported difficulty in explaining the test to women and felt unable to provide the necessary information to adequately inform women within their appointment time. The test offered (the triple test) and potential pathway of subsequent care, were identified as sources of professional and personal conflict by midwives. The expectation that midwives would provide a universal offer of Down's syndrome serum screening but be unable to support women regarding termination of pregnancy also created dissonance. Conclusions., The feasibility of proceeding with a universal serum screening programme for Down's syndrome is questionable in countries which legally or culturally oppose termination of pregnancy. Professionals practising within environments such as this experience conflict in their role, which affects communication with women when discussing screening tests. Relevance to clinical practice., As midwives are often, the primary health professional providing information to women, it is important that midwives are key participants in ongoing planning and discussions about screening policy to ensure programmes are implemented successfully. [source]

Congenital toxoplasmosis: late pregnancy infections detected by neonatal screening and maternal serological testing at delivery

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 6 2007
Eleonor G. Lago
Summary The first aim of this study was to determine the prevalence of congenital toxoplasmosis in newborn infants treated by the public health system in Porto Alegre, a city in southern Brazil, using neonatal screening for Toxoplasma gondii -specific IgM. The second aim was to investigate whether the cases detected by this approach could have been identified by the prenatal screening for antibodies to T. gondii that was performed in the same population. A fluorometric assay was used to analyse T. gondii -specific IgM in filter paper specimens obtained from newborn infants for routine screening for metabolic diseases. When the specific IgM was positive, serum samples from the infant and the mother were requested for confirmatory serological testing, and the infant underwent clinical examination. Among 10 000 infants screened for T. gondii -specific IgM, seven filter paper samples were positive, and congenital toxoplasmosis was confirmed in six patients. The prevalence of IgM specific for T. gondii was 6/10 000 [95% CI 2/10 000, 13/10 000]. One infected infant had already been identified in the maternity ward before birth, three had been identified by maternal serology at delivery, and two infants with congenital toxoplasmosis were identified solely through neonatal screening. Although four mothers of the patients with congenital toxoplasmosis received prenatal care, and three mothers had one or two serological tests for T. gondii -specific antibodies (one at first trimester, one at first and second trimesters, and the other at second and third trimesters), they were not identified during pregnancy as infected. Neonatal screening identified cases of infection not detected by obtaining only one or two serum samples from pregnant women for T. gondii serology, mainly when infection was acquired and transmitted in late pregnancy. Maternal serology at delivery and neonatal screening were especially useful in the identification of infants with congenital toxoplasmosis when the mother did not receive regular prenatal serological testing or prenatal care. [source]

Descriptive epidemiology of Down's syndrome in Estonia

Sixteen years of prenatal consultations for the N370S/N370S Gaucher disease genotype: What have we learned?

PRENATAL DIAGNOSIS, Issue 10 2010
Yael Eitan
Abstract Objective Although prenatal diagnosis and genotyping are available for Gaucher disease, genetic counseling for an affected child's parents reflects the inability to predict disease course with certainty. The purpose of this survey is to ascertain disease status of children identified by prenatal screening. Methods All carrier couples for glucocerebrosidase mutations who were counseled at our large Gaucher Clinic were included; none had genotyped the fetus. Medical status of children was assessed by questionnaires and data were collected from clinic charts and/or telephone contact with the parents. Results Of 34 children born, 1 died in utero, 5 fetuses (N370S/N370S) aborted. Of 21 genotyped N370S/N370S, 7 children had Gaucher-like symptoms/signs but for only one child (two symptoms) were these ascribable to Gaucher disease; four children had non-Gaucher symptoms/signs. Conclusion Of 21 children whose parents pursued prenatal counseling for Gaucher disease and were found to have the N370S/N370S genotype, none has presented with severe disease with follow-up of 15 years. The Israeli experience shows that Gaucher disease N370S screening does not identify children requiring treatment, but rather leads to termination of asymptomatic fetuses; this may lead to reconsideration of guidelines regarding Gaucher screening. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Ethnic differences in participation in prenatal screening for Down syndrome: A register-based study

PRENATAL DIAGNOSIS, Issue 10 2010
Mirjam P. Fransen
Abstract Objective To assess ethnic differences in participation in prenatal screening for Down syndrome in the Netherlands. Methods Participation in prenatal screening was assessed for the period 1 January 2009 to 1 July 2009 in a defined postal code area in the southwest of the Netherlands. Data on ethnic origin, socio-economic background and age of participants in prenatal screening were obtained from the Medical Diagnostic Centre and the Department of Clinical Genetics. Population data were obtained from Statistics Netherlands. Logistic regression models were used to assess ethnic differences in participation, adjusted for socio-economic and age differences. Results The overall participation in prenatal screening was 3865 out of 15 093 (26%). Participation was 28% among Dutch women, 15% among those from Turkish ethnic origin, 8% among those from North-African origin, 15% among those from Aruban/Antillean origin and 26% among women from Surinamese origin. Conclusions Compared to Dutch women, those from Turkish, North-African, Aruban/Antillean and other non-Western ethnic origin were less likely to participate in screening. It was unexpected that women from Surinamese origin equally participated. It should be further investigated to what extent participation and non-participation in these various ethnic groups was based on informed decision-making. Copyright © 2010 John Wiley & Sons, Ltd. [source]

PP13 stability in first trimester maternal serum and whole blood

PRENATAL DIAGNOSIS, Issue 6 2010
N. J. Cowans
Abstract Background Maternal serum placental protein 13 (PP13) has been proposed as a marker for prenatal screening of pre-eclampsia (PE) and other adverse pregnancy outcomes. This study aims to examine the stability of PP13 at different routine temperatures. Methods Maternal serum pools and whole blood samples were stored at ,30 °C', room temperature or refrigerator temperature. Further, serum pools were also subjected to repeated freeze,thaw cycles. PP13 was measured at set time points using an AutoDELFIA® research assay. Results Levels of PP13 are stable, defined as less than 10% change in concentration, in serum for 17.4 h at ,30 °C', 3.4 days at room temperature and for at least 34 days at refrigerator temperature. PP13 concentration is not altered following three ,20 °C to room temperature freeze,thaw cycles. PP13 is stable in whole blood for at least 3 days at all three temperatures studied. Conclusions PP13 is a suitably stable molecule and can be treated under routine laboratory and normal transport temperatures. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Prediction of adverse pregnancy outcomes by combinations of first and second trimester biochemistry markers used in the routine prenatal screening of Down syndrome

PRENATAL DIAGNOSIS, Issue 5 2010
Tianhua Huang
Abstract Objective To investigate the associations between four defined adverse pregnancy outcomes and levels of first and second trimester maternal serum markers focusing in particular on how well combinations of markers predict these adverse outcomes. Methods This was a retrospective review of associations between first and second trimester serum markers and adverse pregnancy outcomes among 141 698 women who underwent prenatal screening for Down syndrome in Ontario, Canada. Detection rates (DR), false positive rates (FPR), and odds ratios were estimated using both single and combinations of markers for the adverse outcomes defined. Results Women with decreased second trimester unconjugated oestriol (uE3), deceased first trimester maternal serum pregnancy-associated plasma protein A (PAPP-A), increased second trimester serum alpha fetoprotein (AFP), or increased second trimester total human chorionic gonadotrophin (hCG) were at greater risk of developing adverse pregnancy outcomes. At a 5% FPR, combinations of these markers predicted at best 33.3% of fetal loss and 31.5% of preterm births (PTB) before 32 weeks of gestation. Conclusion There are significant associations between the levels of first and second trimester serum markers and adverse obstetric outcomes. However, even combinations of these markers can only predict adverse obstetric outcomes with modest accuracy. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Trends in prenatal screening and diagnostic testing among women referred for advanced maternal age

PRENATAL DIAGNOSIS, Issue 3 2010
Naomi Nakata
Abstract Objective We evaluated the trends in uptake of amniocentesis and chorionic villi sampling (CVS) for prenatal diagnosis compared with uptake of first and second trimester prenatal serum screening for Down syndrome among patients referred for genetic counseling for advanced maternal age (AMA). Methods Patients referred for AMA genetic counseling from 2001 through 2008 were informed of both prenatal serum screening and invasive diagnostic testing options. Testing offered and testing decisions were entered in a computer database and uptake rates calculated for each year with trends compared using logistic regression analysis. Results From 2001 through 2007, we observed a decline in amniocentesis and CVS uptake (p = 0.0001). This trend reversed in 2008 for both invasive procedures (p = 0.0001). Uptake of prenatal serum screening increased over the study period with uptake of first trimester screening increasing 1.7 fold in 2008. Conclusion Improved prenatal screening tests and increased availability of screening for AMA patients has led to a steady decline in uptake of invasive testing from 2001 through 2007. This trend reversed from 2007 through 2008. Possible reasons for this reversal are discussed. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Fluorescence in situ hybridization in prenatal screening: lessons from an inherited chromosome 18 marker

PRENATAL DIAGNOSIS, Issue 12 2009
Morgane Valentin
No abstract is available for this article. [source]

Commentary: The federal ,Prenatally and Postnatally Diagnosed Conditions Awareness Act'

PRENATAL DIAGNOSIS, Issue 9 2009
Philip R. Reilly
Abstract The recently enacted federal law, the ,Prenatally and Postnatally Diagnosed Conditions Awareness Act' (United States Public Law 110,374) seeks to improve opportunities for parents and pregnant women to anticipate and understand the likely life course of children born with Down syndrome and other (unspecified) conditions. The law is in part a response to the continued growth of prenatal screening and testing. For example, the American College of Obstetricians and Gynecologists' Practice Bulletin 77 recommends that ,Screening and invasive diagnostic testing for aneuploidies be available to all women who present for prenatal care before 20 weeks of gestation regardless of maternal age.' Emerging technologies anticipate an era in which the scope of prenatal screening and testing will be much larger than it is today. Inevitably, more women will find themselves facing the hard question of whether to continue or end a pregnancy in which a fetus has been found to have a significant abnormality. While the new federal law is not likely to have a major impact on obstetric practice, it may be a harbinger of renewed wide-scale public debate concerning the ethics of prenatal screening. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Prenatal screening for serious congenital heart defects using nuchal translucency: a meta-analysis

Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center

PRENATAL DIAGNOSIS, Issue 11 2008
Nanette Okun
Abstract Objectives To evaluate the performance of integrated prenatal screening (IPS) and first trimester combined screening (FTS) for trisomy 21 in a large Canadian urban center. Method Prospective data collection on women having FTS at one center from 1 November 2003 to 31 December 2005, or IPS at another from 1 January 2003 to 31 December 2005. A positive screen was defined as adjusted risk for trisomy 21 , 1/200 at term or nuchal translucency , 3.5 mm. Results 32 227 and 14 487 women were screened in the IPS and FTS programs, respectively. Detection rates (DRs) and positive rates (PRs) for trisomy 21 were 88.4% (95% CI: 81.6,91.5) and 3.3% (95% CI: 3.1,3.5) for IPS, and 83.9% (95% CI: 74.7,93.0) and 4.0% (95% CI: 3.7,4.3) for FTS. DR adjusted for viability bias was 85.2% for IPS and 78.6% for FTS. Applying both the screens to the 78 134 women who submitted prenatal screens in Ontario in 2005, thereby eliminating the effect of differences in the distribution of maternal age between screens, gave a DR (corrected for viability bias) and PR of 81 and 3.1% for IPS, and 76 and 3.4% for FTS. Conclusions Both IPS and FTS perform well and are feasible in a practical clinical setting. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Application of proteomics for the identification of differentially expressed protein markers for Down syndrome in maternal plasma

PRENATAL DIAGNOSIS, Issue 8 2008
Aggeliki Kolialexi
Abstract Background Despite the large impact of ultrasonographic and biochemical markers on prenatal screening, the ability to accurately diagnose Down syndrome (DS) is still limited and better diagnostic testing is needed. Methods Plasma from 8 women carrying a DS foetus and 12 with non-DS foetuses matched for gestational age, maternal age and ethnicity, in the second trimester of pregnancy, was analysed by two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in order to identify biomarkers for DS. Results Gel comparison revealed nine proteins differentially expressed in maternal plasma in women with DS foetuses. Eight proteins, transthyretin (TTHY), ceruloplasmin (CERU), afamin (AFAM), alpha-1-microglobulin (AMBP), apolipoprotein E (APOE), serum amyloid P-component (SAMP), histidine-rich glycoprotein (HRG) and alpha-1-antitrypsin (A1AT) were up-regulated and one, clusterin (CLUS), down-regulated. All nine proteins are known to be involved in foetal growth and development. APOE, SAMP, AFAM and CLUS are associated with the DS phenotype. Western blot and densitometric analysis of APOE and SAMP confirmed the increase of both proteins by 19 and 48% respectively. Conclusions All differentially expressed proteins are candidate biomarkers for DS, providing opportunities for the development of non-invasive prenatal diagnosis. As these are preliminary findings, follow-up experiments are needed for their evaluation. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Effect of maternal smoking on prenatal screening for Down syndrome and trisomy 18 in the first trimester of pregnancy

PRENATAL DIAGNOSIS, Issue 3 2008
Pierre Miron
Abstract Objectives To assess the impact of maternal smoking on first-trimester prenatal screening results for Down syndrome and trisomy 18. Methods Data on maternal smoking status, maternal age, gestational dating, levels of free beta-human chorionic gonadotrophin (,-hCG) and pregnancy-associated plasma protein A (PAPP-A) in maternal blood and fetal nuchal translucency (NT) thickness were analyzed from a cohort of 53 114 women. Statistical analyses were carried out for crude and adjusted comparisons between smoking and nonsmoking groups. Results In women who smoked during the first trimester of pregnancy, PAPP-A and free ,-hCG levels from dried blood were significantly decreased (p < 0.001) and fetal NT thickness was significantly increased (p < 0.001). For an overall risk assessment combining maternal age and biochemical and ultrasound markers, no significant changes for Down syndrome were found with smoking, but significant increases in average risk as well as in positive rates were found for trisomy 18 (p < 0.001). A potential association between maternal smoking and trisomy 18 remains to be clarified. Conclusion Adjustment for smoking is recommended in first-trimester prenatal screening for trisomy 18 and probably not warranted for Down syndrome because of the cancelling effects of decreased free ,-hCG and increased NT. Further research is required to demonstrate a biological association between maternal smoking and trisomy 18. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Preconceptional and prenatal screening for fragile X syndrome: Experience with 40 000 tests

PRENATAL DIAGNOSIS, Issue 11 2007
Michal Berkenstadt
Abstract Objectives To determine the carrier frequency of fragile X syndrome, and the rate of expansion from premutation (PM) carrier to full mutation (FM) fetus. Methods Results were analyzed on women with no family history of fragile X syndrome, or who were PM/FM carriers, who were tested between January 1994 and June 2004. PM was defined 55,199 repeats, FM above 200. Results Out of 40 079 women screened, 5 FM and 255 PM carriers were detected. There was no significant difference in carrier frequency between those with versus those without family history of mental retardation or developmental abnormalities: 1 in 128 (28/3596) versus 1 in 157 (232/36 483). However, the median of repeats differed significantly: 58 and 66 repeats, respectively, (P < 0.0001). Invasive prenatal diagnosis was carried out in 370 pregnancies (7 FM and 363 PM). Thirty FM fetuses were detected. There was a lower expansion rate in cases without a family history: 10% (17/169 PMs) compared to 50% (11/22 PMs) in those with a history, but this could be accounted for by the difference in allele size. Conclusion There is now sufficient information on screening parameters and prenatal diagnosis of fragile X syndrome to offer testing to women of reproductive age. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Truncation limits for CT marker ratios in prenatal screening for Down syndrome

PRENATAL DIAGNOSIS, Issue 2 2007
Nicholas J. Wald
No abstract is available for this article. [source]

Sequential and contingent prenatal screening for Down syndrome

PRENATAL DIAGNOSIS, Issue 9 2006
Nicholas J Wald
Abstract Objective To compare the Integrated test in three policies for prenatal Down syndrome screening: Integrated screening for all women, sequential screening (first-trimester tests allowing early completion of screening for high-risk pregnancies), and Contingent screening (early completion of screening for high- and low-risk pregnancies). Design and Methods Estimation of detection rates (DRs) and false-positive rates (FPRs) using Monte Carlo simulation and cost effectiveness for each method. Setting and Population Down syndrome affected and unaffected pregnancies studied in the Serum Urine and Ultrasound Screening Study (SURUSS). Results and Main Outcomes Integrated screening has the best screening performance. The performance of the other two policies approached that of Integrated screening as the first-trimester test FPR decreased. If the first-trimester FPR is set to 0.5% (risk , 1 in 30) with an overall DR of 90%, sequential and contingent screening yield overall FPRs of 2.25% and 2.42%, respectively, and 66% of the affected pregnancies are detected by the first-trimester test. The Integrated test on all women yields an FPR of 2.15%. With sequential screening, 99.5% of women would proceed to an Integrated test, or 30% with contingent screening if those with first-trimester test risks of ,1 in 2000 are classified screen-negative and receive no further testing. About 20% of affected pregnancies identified in the first trimester using sequential or contingent screening would have unnecessary terminations (they would miscarry before the early second trimester). Contingent screening is the most cost-effective if there is no alphafetoprotein screening for neural tube defects, otherwise Integrated screening is more cost-effective. Conclusions Integrated screening for all women is the simplest, most effective, and the safest policy. Contingent screening is the most complex with the lowest screening performance. Making an earlier diagnosis with sequential and contingent screening has adverse consequences that are sufficient to discourage their use. Copyright © 2006 John Wiley & Sons, Ltd. [source]

The utility assessment of Chinese pregnant women towards the birth of a baby with Down syndrome compared to a procedure-related miscarriage

PRENATAL DIAGNOSIS, Issue 9 2006
Yiu Man Chan
Abstract Objective This study was performed to investigate the preferences of Chinese pregnant women for Down syndrome-affected birth compared to invasive test-related miscarriage, using the standard gamble approach, and to investigate whether there is a difference in Utility Score between general obstetric patients and those who request prenatal screening. Methods An interviewer-administered survey was conducted on 67 women who presented to the General Obstetric Clinic for booking visits and 69 women who presented to the first-trimester Combined Screening Clinic for fetal Down syndrome in a University Obstetric Unit. Preferences for Down syndrome-affected birth compared to invasive test-related miscarriage were assessed using the standard gamble approach. The differences in Utility Scores for the two outcomes and difference in scores between the two study groups were compared. Results There was no significant difference in any of the Utility Scores studied between the two study groups. Therefore the summary statistics were performed using the whole study population. The median Utility Score for a Down syndrome-birth was 0.20 (IQR: 0.10,0.40), which was significantly lower than that of 0.55 (IQR: 0.40,0.80) for a procedure-related miscarriage (p < 0.001). Also, the Utility Scores were neither found to be associated with any particular patient demographic characteristics nor their perception of the functional disability of individuals with Down syndrome. Conclusion The Chinese pregnant women in Hong Kong consider a Down syndrome-affected birth as a much worse health state and life event than a miscarriage. Whether or not to have a screening test appeared to be a result of accessibility and affordability rather than fundamental differences in attitude towards Down syndrome. The findings of the study provide important information on how prenatal screening and diagnosis of fetal chromosomal abnormalities should be offered. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Uterine lavage in prenatal screening for aneuploidy in continuing pregnancies

PRENATAL DIAGNOSIS, Issue 10 2005
Xiao Xi Zhao
No abstract is available for this article. [source]

Educating general practitioners about prenatal testing: approaches and challenges

PRENATAL DIAGNOSIS, Issue 7 2005
Sylvia Metcalfe
Abstract Objectives To examine the effects of an education intervention on the knowledge and practice behaviours of general practitioners (GPs) regarding prenatal screening and diagnostic testing in Melbourne, Australia. Methods A single group, pre-test, repeated post-test design was used. Information on demographics, knowledge, behaviours and skills was collected via a self-administered questionnaire prior to the educational intervention. Responses to individual questions were coded and scores calculated, as well as a percent total score. Following the education, data were again collected, immediately afterwards (Post-Q) and six-to-eight months later (Foll-Q). Results Data for all three time points were collected from 63 GPs and showed a variable, and relatively poor knowledge regarding aspects of prenatal testing, especially before education. The percent mean total score at baseline was 51.2 ± 1.59% (CI 48.02 to 54.39), which increased significantly (p < 0.001) in both Post-Q (62.88 ± 1.51%; CI 59.86 to 65.89) and Foll-Q (58.92 ± 1.6%; CI 55.71 to 62.12). Conclusion The educational intervention significantly increased knowledge and practice behaviour of GPs, even up to eight months later, but this could be improved further, to a considerable extent. There is a need for ongoing multi-faceted approaches to educating GPs on prenatal testing to ensure that they are engaged in appropriate practice. Copyright © 2005 John Wiley & Sons, Ltd. [source]