Non-invasive prenatal testing in mitigating concerns from invasive prenatal diagnostic testing: retrospective assessment of utility in an academic healthcare system in the US.

OBJECTIVE: Non-invasive prenatal testing (NIPT) is a front-line screening for fatal chromosomal aneuploidy. In pregnant women with a risk of having fetal congenital disorders, NIPT is anticipated to reduce the needs of invasive prenatal diagnostic test (IPD). The objective of this study was to understand the acceptance of NIPT and the utility of NIPT to mitigate concerns about IPD in the US high-risk pregnancy management. DESIGN AND SETTING: This was a retrospective observational research using healthcare records obtained from an academic healthcare system in the US. The study consisted of site-level longitudinal analysis and patient-level cross-sectional analysis. PARTICIPANT: A total of 5660 new high-risk pregnancies with age ≥35 years were identified for the longitudinal trend analysis. Cross-sectional utility assessment included 2057 pregnant women. EXPOSURE AND OUTCOME MEASURES: Longitudinal trends of NIPT order, IPD procedure and the number of patients diagnosed with high-risk pregnancy were descriptively summarised. In the cross-sectional assessment, we tested the association between the use of NIPT and IPD using multivariable regression. RESULTS: The rate of increase in the NIPT use exceeded the changes in the number of high-risk pregnancies with age ≥35 years, while the number of annual IPD procedures has fluctuated without specific trends. There was no significant association between the numbers of NIPT and IPD with the adjusted ORs between 0.90 and 1.14 (p>0.1). The order of NIPT was not selected as an independent variable predicting the use of IPD. Clinical characteristics indicating low socioeconomic status and limited healthcare coverage are associated with less use of NIPT and lower clinical utility. CONCLUSION: Although prenatal care accepted NIPT over the last decade, the utility of NIPT in mitigating concerns on IPD is unclear and needs further investigation. Limited clinical utility should be addressed in the context of disparity in prenatal care.

Eliciting women's preference for prenatal testing in China: a discrete choice experiment.

BACKGROUND: Pregnancy tests can be used for the early diagnosis of fetal problems and can prevent abnormal birth in pregnancies. Yet, testing preferences among Chinese women are poorly investigated. METHODS: We developed a Discrete Choice Experiment with 5 attributes: test procedure, detection rate, miscarriage rate, time to wait for result, and test cost. By studying the choices that the women make in the hypothetical scenarios and comparing the attributes and levels, we can analyze the women's preference of prenatal testing in China. RESULTS: Ninety-two women completed the study. Respondents considered the test procedure as the most important attribute, followed by detection rate, miscarriage rate, wait time for result, and test cost, respectively. The estimated preference weight for the non-invasive procedure was 0.928 (P < 0.0001). All other attributes being equal, the odds of choosing a non-invasive testing procedure over an invasive one was 2.53 (95% confidence interval, 2.42-2.64; P < 0.001). Participants were willing to pay up to RMB$28,810 (approximately US$4610) for a non-invasive test, RMB$6061(US$970) to reduce the miscarriage rate by 1% and up to RMB$3356 (US$537) to increase the detection rate by 1%. Compared to other DCE (Discrete Choice Experiment) studies regarding Down's syndrome screening, women in our study place relatively less emphasis on test safety. CONCLUSIONS: The present study has shown that Chinese women place more emphasis on detection rate than test safety. Chinese women place great preference on noninvasive prenatal testing, which indicate a popular need of incorporating noninvasive prenatal testing into the health insurance coverage in China. This study provided valuable evidence for the decision makers in the Chinese government.

Age-based differences in the predictive accuracy of a one-size-fits-all risk-cutoff value in prenatal integrated screening for Down syndrome.

OBJECTIVE: The objective of this study is to assess variation in detection and false positive rates and adverse pregnancy outcomes across different age groups when a one-size-fits-all risk-cutoff value, such as 1/270, is used in integrated screening for Down syndrome. METHOD: A Monte Carlo simulation was utilized to estimate the detection and false positive rates as well as adverse pregnancy outcomes. RESULTS: Using a one-size-fits-all risk-cutoff value, such as 1/270, can result in considerably high variations in detection and false positive rates across maternal ages and lead to a higher than the minimum possible total number of adverse outcomes. CONCLUSION: Our findings indicate that the one-size-fits-all risk-cutoff value of 1/270, commonly used in DS screening, should be revisited and alternative (possibly age-based) cutoff values and strategies should be considered. © 2017 John Wiley & Sons, Ltd.

Management of suspected primary Toxoplasma gondii infection in pregnant women in Norway: twenty years of experience of amniocentesis in a low-prevalence population.

BACKGROUND: Primary infection with Toxoplasma gondii during pregnancy may pose a threat to the fetus. Women infected prior to conception are unlikely to transmit the parasite to the fetus. If maternal serology indicates a possible primary infection, amniocentesis for toxoplasma PCR analysis is performed and antiparasitic treatment given. However, discriminating between primary and latent infection is challenging and unnecessary amniocenteses may occur. Procedure-related fetal loss after amniocentesis is of concern. The aim of the present study was to determine whether amniocentesis is performed on the correct patients and whether the procedure is safe for this indication. METHODS: Retrospective study analysing data from all singleton pregnancies (n = 346) at Oslo University Hospital undergoing amniocentesis due to suspected maternal primary toxoplasma infection during 1993-2013. Maternal, neonatal and infant data were obtained from clinical hospital records, laboratory records and pregnancy charts. All serum samples were analysed at the Norwegian Institute of Public Health or at the Toxoplasma Reference Laboratory at Oslo University Hospital. The amniocenteses were performed at Oslo University Hospital by experienced personnel. Time of maternal infection was evaluated retrospectively based on serology results. RESULTS: 50% (173) of the women were infected before pregnancy, 23% (80) possibly in pregnancy and 27% (93) were certainly infected during pregnancy. Forty-nine (14%) women seroconverted, 42 (12%) had IgG antibody increase and 255 (74%) women had IgM positivity and low IgG avidity/high dye test titre. Fifteen offspring were infected with toxoplasma, one of them with negative PCR in the amniotic fluid. Median gestational age at amniocentesis was 16.7 gestational weeks (GWs) (Q1 = 15, Q3 = 22), with median sample volume 4 ml (Q1 = 3, Q3 = 7). Two miscarriages occurred 4 weeks after the procedure, both performed in GW 13. One of these had severe fetal toxoplasma infection. CONCLUSIONS: Half of our study population were infected before pregnancy. In order to reduce the unnecessary amniocenteses we advise confirmatory serology 3 weeks after a suspect result and suggest that the serology is interpreted by dedicated multidisciplinary staff. Amniocentesis is safe and useful as a diagnostic procedure in diagnosing congenital toxoplasma infection when performed after 15 GW.

Prenatal Diagnosis Procedures and Techniques to Obtain a Diagnostic Fetal Specimen or Tissue: Maternal and Fetal Risks and Benefits.

OBJECTIVE: To provide maternity care providers and their patients with current evidence-based guidelines for maternal risk/benefit counselling for a prenatally identified at-risk pregnancy that requires ultrasound-guided prenatal diagnostic procedures and/or techniques for a genetic diagnosis and for subsequent pregnancy management decisions on questions such as level of obstetrical care provider, antenatal surveillance, location of care and delivery, and continuation or termination of pregnancy. This guideline is limited to maternal risk/benefit counselling and pregnancy management decisions for women who require, or are considering, an invasive ultrasound-guided procedure or technique for prenatal diagnosis. PATIENT POPULATION: Pregnant women identified as having an increased risk of a fetal genetic abnormality secondary to the process of established prenatal screening protocols (maternal serum±imaging, high-risk cell-free DNA results, abnormal diagnostic fetal imaging, or a positive family history of an inherited condition). These women may require or request counselling about pregnancy risks and benefits of an invasive ultrasound-guided procedure to determine the etiology, diagnosis, and/or pathology for the possible fetal anomaly or anomalies. EVIDENCE: Published literature was retrieved through searches of Medline, PubMed, and the Cochrane Library in and prior to June 2014 using an appropriate controlled vocabulary (prenatal diagnosis, amniocentesis, chorionic villi sampling, cordocentesis) and key words (prenatal screening, prenatal genetic counselling, post-procedural pregnancy loss rate). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English and published from January 1985 to June 2014. Searches were updated on a regular basis and incorporated in the guideline to June 2014. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical speciality societies. VALUES: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Health benefits, side effects, and risks: Patient informed consent, knowledge translation, genetic prenatal risk assessment, anxiety relief, anxiety creation, advocacy, understanding or limitation for fetal testing, pregnancy management choice, pregnancy complication or loss, timely and improved care for birth of a neonate with recognized morbidity. Recommendations 1. The health care provider should counsel the at-risk pregnant woman on the different levels of genetic fetal testing in order for her to have a clear understanding and expectation of the level of testing and type of results that are offered. (III-B) 2. As part of the informed consent process, the health care provider should review with the at-risk pregnant woman the risks and benefits of in utero genetic diagnostic techniques associated with fetal genetic testing options. (III-A) 3. During risk/benefit counselling, the health care provider should advise that the best estimate of the pregnancy loss rate related to: a.amniocentesis is 0.5% to 1.0% (range 0.17 to 1.53%) (I) b.chorionic villus sampling is 0.5% to 1.0% (I) and c.cordocentesis or percutaneous umbilical blood sampling is 1.3% for fetuses with no anomalies and 1.3% to 25% for fetuses with single or multiple anomalies or intrauterine growth restriction. (II-2A).

Objectif : Offrir aux fournisseurs de soins de maternité et à leurs patientes des lignes directrices factuelles contemporaines en ce qui concerne les services de counseling traitant des risques et des avantages maternels propres à la tenue des interventions diagnostiques prénatales orientées par échographie (et/ou des techniques permettant l'établissement d'un diagnostic génétique) nécessaires dans les cas où il a été établi pendant la période prénatale que la grossesse serait exposée à des risques, ainsi qu'en ce qui concerne la prise de décisions subséquentes quant à la prise en charge de la grossesse (questions abordant des aspects tels que le niveau du fournisseur de soins obstétricaux, la surveillance prénatale, le lieu où devraient se dérouler les soins et l'accouchement, et la décision de poursuivre ou d'interrompre la grossesse). La présente directive clinique se limite aux services de counseling traitant des risques et des avantages maternels, et aux décisions en matière de prise en charge de la grossesse pour les femmes qui nécessitent (ou qui envisagent) la mise en œuvre d'une intervention ou d'une technique effractive orientée par échographie aux fins de l'établissement d'un diagnostic prénatal. Population de patientes : Femmes enceintes identifiées, à la suite de la mise en œuvre de protocoles établis de dépistage prénatal (taux sériques maternels ± imagerie, résultats d'analyse de l'ADN acellulaire indiquant des risques élevés, résultats anormaux au moment de l'imagerie fœtale diagnostique ou antécédents familiaux de troubles héréditaires), comme étant exposées à un risque accru d'anomalie génétique fœtale. Ces femmes pourraient nécessiter ou demander des services de counseling au sujet des risques et des avantages pour la grossesse de la tenue d'une intervention effractive orientée par échographie visant à déterminer l'étiologie, le diagnostic, et/ou la pathologie de possibles anomalies fœtales. Résultats : La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans Medline, PubMed et The Cochrane Library jusqu'en juin 2014 au moyen d'un vocabulaire contrôlé (« prenatal diagnosis ¼, « amniocentesis ¼, « chorionic villi sampling ¼, « cordocentesis ¼) et de mots clés (« prenatal screening ¼, « prenatal genetic counselling ¼, « post-procedural pregnancy loss rate ¼) appropriés. Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre janvier 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Valeurs : La qualité des résultats a été évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau). Avantages, désavantages et coûts : Consentement éclairé de la patiente, transfert des connaissances, évaluation du risque génétique prénatal, soulagement de l'anxiété, création d'anxiété, défense des droits, compréhension du dépistage fœtal, limites du dépistage fœtal, choix en matière de prise en charge de la grossesse, complication de la grossesse ou fausse couche, soins opportuns et améliorés pour l'accouchement d'un enfant présentant une morbidité reconnue. Recommandations 1. Les fournisseurs de soins de santé devraient offrir, aux femmes enceintes exposées à des risques, des services de counseling au sujet des différents niveaux du dépistage génétique fœtal, de façon à ce qu'elles puissent bien comprendre le niveau du dépistage qui leur est offert et les types de résultats auxquels elles sont en droit de s'attendre. (III-B) 2. Les fournisseurs de soins de santé devraient offrir, aux femmes enceintes exposées à des risques, des services de counseling au sujet de la ou des techniques de diagnostic génétique in utero qui sont associées aux options de dépistage génétique fœtal et en passer en revue les risques et les avantages dans le cadre du processus de consentement éclairé. (III-A) 3. Dans le cadre des services de counseling sur les risques et les avantages, les fournisseurs de soins de santé devraient aviser leurs patientes des meilleures estimations suivantes en ce qui concerne le taux de fausse couche : a. amniocentèse = 0,5%-1,0 % (plage : 0,17-1,53 %) (I) b. prélèvement de villosités choriales = 0,5 %-1,0 % (I) et c. cordocentèse (ou prélèvement percutané de sang ombilical) = 1,3 %, dans le cas des fœtus sans anomalies, et 1,3 %-25 %, dans le cas des fœtus présentant une ou des anomalies ou un retard de croissance intra-utérin. (II-2A).

Prenatal diagnosis: From policy to practice. Two distinct ways of managing prognostic uncertainty and anticipating disability in Brazil and in France.

Prenatal diagnosis (PND) has gradually established itself as part of the pregnancy monitoring process, with a view to reducing the number of births of children exposed to disability by combining the use of biomedical tools with laws that authorise abortion in cases of foetal pathology. This article looks at how laws which vary from one country to another modulate the way in which PND practices are organised on a daily basis, determine the discourse of practitioners and lead them to adopt specific stances during prenatal consultations with couples coping with a foetal anomaly. We present a comparative ethnographic study, which took place between 2009 and 2011 in France and Brazil, in reference units, based on observation of consultations, professional meetings, and interviews with health practitioners. The fact that access to abortion due to foetal pathology is possible in France, and criminalised in Brazil, conditions how doctors analyse the framework of their medical practice and approach the issue of disability with couples during consultations. In France, practitioners would appear to be satisfied with a professional framework that they themselves created. Faced with prognostic uncertainty, the legal obligation to inform encourages them to discuss all of the potential complications of the diagnosed anomalies and leads them to provide probabilistic information about the life of the child to be, supported by evidence-based medicine. In Brazil, in the public service, the lack of access to abortion has created a malaise among practitioners who criticise this impediment to the objective nature of their practice and to the quality of the information that they provide. Some use prognostic uncertainty to direct the thoughts of women and couples towards the dynamics proper to each individual human trajectory within a given family and a specific social environment.

Comparing outcomes and costs between contingent and combined first-trimester screening strategies for Down's syndrome.

OBJECTIVE: To compare a contingent strategy with a combined strategy for prenatal detection of Down's syndrome (DS) in terms of cost, outcomes and safety. STUDY DESIGN: The contingent strategy was based on a simulation, removing measurement of the free beta subunit of human chorionic gonadotropin (free ßhCG) and calculating the DS risk retrospectively in 32,371 pregnant women who had been screened with the combined strategy in the first trimester. In the contingent strategy, a risk between 1:31 and 1:1000 in the first trimester indicated further testing in the second trimester (alpha-fetoprotein, inhibin A, unconjugated oestriol and free ßhCG). The cut-off risk values for the contingent and combined strategies in the first trimester were 1:30 and 1:250, respectively, and the cut-off risk value for integrated screening in the second trimester was 1:250. Costs were compared in terms of avoided DS births, and the ratio of loss of healthy fetuses following invasive procedures per avoided DS birth was calculated. RESULTS: The combined strategy had sensitivity of 40/44 (90.9%) and a false-positive rate of 2.8%. Corresponding values for the contingent strategy were 39/44 (88.6%) and 1.3%, respectively. Only 11% of pregnant women required tests in the second trimester, and the approximate cost reduction for each avoided DS birth was 5000€. The ratio of lost healthy fetuses following invasive procedures per avoided DS birth improved by up to 0.65. CONCLUSION: The contingent strategy has similar effectiveness to the combined strategy, but has lower costs and fewer invasive procedures.

Cell-free DNA screening for fetal aneuploidy as a clinical service.

Non-invasive prenatal testing (NIPT) through the analysis of cell free (cf)DNA is revolutionizing prenatal screening for fetal aneuploidy. Current methods used in clinical practice include shotgun massively parallel sequencing (s-MPS); targeted (t-MPS); and an approach that takes advantage of single nucleotide polymorphism (SNP) differences between mother and fetus. Efficacy of cfDNA testing for the common autosomal trisomies far exceeds that of conventional screening. Depending on the methodology used, reasons for discordancy between cfDNA results and fetal karyotype can include true fetal mosaicism, confined placental mosaicism, presence of a maternal karyotype abnormality, insufficient counting due to low fetal fraction, and a vanishing twin. Among the possible cfDNA strategies a Primary test has the highest performance but is expensive, while a Contingent cfDNA test can achieve high performance at a relatively low cost. Practicalities to be considered in the provision of testing include pretest counseling about the scope and accuracy of the testing, the interpretation of results when there is a low fetal fraction and follow-up studies for positive test results. The role of first trimester nuchal translucency measurement and conventional biochemical testing needs to be reassessed in the context of the use of cfDNA.

Women's and healthcare professionals' preferences for prenatal testing: a discrete choice experiment.

OBJECTIVE: This study evaluates pregnant women's and healthcare professionals' preferences regarding specific prenatal screening and diagnostic test characteristics. METHOD: A discrete choice experiment was developed to assess preferences for prenatal tests that differed in seven attributes: minimal gestational age, time to test results, level of information, detection rate, false positive rate, miscarriage risk and costs. RESULTS: The questionnaire was completed by 596 (70.2%) pregnant women and 297 (51.7%) healthcare professionals, of whom 507 (85.1%) and 283 (95.3%), respectively, were included in further analyses as their choice behavior indicated prenatal testing was an option to them. Comparison of results showed differences in relative importance attached to attributes, further reflected by differences in willingness to trade between attributes. Pregnant women are willing to accept a less accurate test to obtain more information on fetal chromosomal status or to exclude the risk of procedure-related miscarriage. Healthcare professionals consider level of information and miscarriage risk to be most important as well but put more emphasis on timing and accuracy. CONCLUSION: Pregnant women and healthcare professionals differ significantly in their preferences regarding prenatal test characteristics. Healthcare professionals should take these differences into consideration when counseling pregnant women on prenatal testing.

The consequences of implementing non-invasive prenatal testing in Dutch national health care: a cost-effectiveness analysis.

OBJECTIVE: Non-invasive prenatal testing (NIPT) using cell-free fetal DNA in maternal plasma has been developed for the detection of fetal aneuploidy. Clinical trials have shown high sensitivity and specificity for trisomy 21 (T21) in both high-risk and average-risk populations. Although its great potential for prenatal medicine is evident, more information regarding the consequences of implementing NIPT in a national programme for prenatal screening is required. STUDY DESIGN: A decision-analytic model was developed to compare costs and outcomes of current clinical practice in The Netherlands using conventional screening only, with two alternatives: implementing NIPT as an optional secondary screening test for those pregnancies complicated by a high risk for T21, and implementing NIPT as primary screening test, replacing conventional screening. Probability estimates were derived from a systematic review of international literature. Costs were determined from a health-care perspective. Data were analysed to obtain outcomes, total costs, relative costs and incremental cost-effectiveness ratios (ICERs) for the different strategies. Sensitivity analysis was used to assess the impact of assumptions on model results. RESULTS: Implementing NIPT as an optional secondary, or as primary screening test will increase T21 detection rate by 36% (from 46.8% to 63.5%) and 54% (from 46.8% to 72.0%), simultaneously decreasing the average risk of procedure-related miscarriage by 44% (from 0.0168% to 0.0094% per pregnant woman) and 62% (from 0.0168% to 0.0064% per pregnant woman), respectively. None of the strategies clearly dominated: current clinical practice is the least costly, whereas implementing NIPT will cause total costs of the programme to increase by 21% (from €257.09 to €311.74 per pregnant woman), leading to an ICER of k€94 per detected case of T21, when utilised as an optional secondary screening test and by 157% (from €257.09 to €660.94 per pregnant woman), leading to an ICER of k€460 per detected case of T21, when utilised as primary screening test. However, implementing NIPT as triage test did result in the lowest expected relative costs per case of T21 diagnosed (k€141). CONCLUSION: NIPT should be implemented in national health care as an optional secondary screening test for those pregnancies complicated by a high risk for T21.

Model-based analysis of costs and outcomes of non-invasive prenatal testing for Down's syndrome using cell free fetal DNA in the UK National Health Service.

BACKGROUND: Non-invasive prenatal testing (NIPT) for Down's syndrome (DS) using cell free fetal DNA in maternal blood has the potential to dramatically alter the way prenatal screening and diagnosis is delivered. Before NIPT can be implemented into routine practice, information is required on its costs and benefits. We investigated the costs and outcomes of NIPT for DS as contingent testing and as first-line testing compared with the current DS screening programme in the UK National Health Service. METHODS: We used a pre-existing model to evaluate the costs and outcomes associated with NIPT compared with the current DS screening programme. The analysis was based on a hypothetical screening population of 10,000 pregnant women. Model inputs were taken from published sources. The main outcome measures were number of DS cases detected, number of procedure-related miscarriages and total cost. RESULTS: At a screening risk cut-off of 1∶150 NIPT as contingent testing detects slightly fewer DS cases, has fewer procedure-related miscarriages, and costs the same as current DS screening (around UK£280,000) at a cost of £500 per NIPT. As first-line testing NIPT detects more DS cases, has fewer procedure-related miscarriages, and is more expensive than current screening at a cost of £50 per NIPT. When NIPT uptake increases, NIPT detects more DS cases with a small increase in procedure-related miscarriages and costs. CONCLUSIONS: NIPT is currently available in the private sector in the UK at a price of £400-£900. If the NHS cost was at the lower end of this range then at a screening risk cut-off of 1∶150 NIPT as contingent testing would be cost neutral or cost saving compared with current DS screening. As first-line testing NIPT is likely to produce more favourable outcomes but at greater cost. Further research is needed to evaluate NIPT under real world conditions.

Prenatal screening for Down syndrome in Australia: costs and benefits of current and novel screening strategies.

OBJECTIVE: To analyse the cost-effectiveness and performance of noninvasive prenatal testing (NIPT) for high-risk pregnancies following first-trimester screening compared with current practice. METHODS: A decision tree analysis was used to compare the costs and benefits of current practice of first-trimester screening with a testing pathway incorporating NIPT. We applied the model to 32 478 singleton pregnancies screened between January 2005 and December 2006, adding Medicare rebate data as a measure of public health system costs. The analyses reflect the actual uptake of screening and diagnostic testing and pregnancy outcomes in this cohort. RESULTS: The introduction of NIPT would reduce the number of invasive diagnostic procedures and procedure-related fetal losses in high-risk women by 88%. If NIPT was adopted by all women identified as high risk by first-trimester combined screening, up to 7 additional Down syndrome fetuses could be confirmed. The cost per trisomy 21 case confirmed, including NIPT was 9.7% higher ($56,360) than the current prenatal testing strategy ($51,372) at a total cost of $3.91 million compared with $3.57 million over 2 years. CONCLUSION: Based on the uptake of screening and diagnostic testing in a retrospective cohort of first-trimester screening in Western Australia, the implementation of NIPT would reduce the number of invasive diagnostic tests and the number of procedure-related fetal losses and increase the cost by 9.7% over two years. Policy planning and guidelines are urgently required to manage the funding and demand for NIPT services in Australia.

Assessment of fetomaternal hemorrhage by Kleihauer-Betke test, flow cytometry and α-fetoprotein after invasive obstetric procedures.

PURPOSE: The aim of this study was to evaluate the passage of fetal red blood cells to the maternal circulation, after invasive obstetric procedures, through the Kleihauer-Betke test, flow cytometry and by measurement of maternal serum alpha-fetoprotein level. METHODS: This prospective descriptive study with patients submitted to amniocentesis, cordocentesis, chorionic villus sampling (CVS), amnioreduction and ventriculoamniotic shunt was performed for karyotype analysis, treatment of hydrocephalus and polyhydramnios and to assess fetal lung maturity. Maternal blood samples were collected before and 60 minutes after the invasive obstetric procedure to search for fetal erythrocytes using the Kleihauer-Betke test, flow cytometry and serum alpha-fetoprotein measurement. RESULTS: Ten invasive obstetric procedures were performed. The mean age of the patients was 29.2 years and the mean gestational age was 29.6 weeks. The procedures were: five amniocenteses, two cordocenteses, one CVS, one ventriculo-amniotic shunt and one amnioreduction with cephalocentesis. The indications for the procedures were: karyotype analysis in five patients, fetal lung maturity assessment in two patients, amnioreduction in one patient, fetal hydrocephalus shunt in one patient and polyhydramnios related to hydranencephaly in one patient. Regarding the path of puncture, three procedures were accomplished through the placenta and seven apart from it. All punctures were successful at the first attempt. There was no significant increase of fetal erythrocyte quantity in maternal blood samples using the Kleihauer-Betke test. After cordocentesis, a significant increase of fetal erythrocytes was detected by flow cytometry and serum alpha-fetoprotein measurement. CONCLUSION: Invasive obstetric procedures during prenatal care are safe when performed by experienced professionals using adequate techniques, with minimal chance of passage of fetal erythrocytes from the fetal compartment.

Survey of prenatal counselling practices regarding aneuploidy risk modification, invasive diagnostic procedure risks, and procedure eligibility criteria in Canadian centres.

OBJECTIVE: To explore prenatal practices related to aneuploidy screening, risk modification, and invasive diagnostic procedures across Canadian centres. METHODS: We conducted a survey of members of the Canadian Association of Genetic Counsellors, the Canadian College of Medical Genetics, and the Canadian Society of Maternal Fetal Medicine, who provide direct counselling or management of prenatal patients in Canada. RESULTS: Eighty-two of 157 respondents indicated that their centre's definition of advanced maternal age was ≥ 35 years, with 33/157 respondents reporting an advanced maternal age definition of ≥ 40 years. The majority of respondents reported that prenatal serum screening for aneuploidy is provincially funded in their province or territory (121/147). The majority of respondents who reported that prenatal screening is not provincially funded (17/147) were from Quebec (14/17). Thirty-nine of 123 respondents reported that their centre defines increased nuchal translucency as ≥ 3.0 mm, whereas 49/123 reported a definition of ≥ 3.5 mm. Sixty-four of 150 respondents reported that the aneuploidy risk provided by serum screening is modified by a soft marker likelihood ratio, whereas 46/150 respondents reported that both age-related and serum screening risks are modified. Fifty-nine of 124 respondents reported that their centre will modify aneuploidy risk after a normal ultrasound; the most commonly cited negative likelihood ratio was 0.5. The most commonly reported procedure-related risk for chorionic villus sampling was 1/100 (123/147) and for amniocentesis was 1/200 (73/142). CONCLUSION: This study demonstrates inconsistencies in prenatal practices and access to screening programs across Canada. The information gained from this study will inform policy advisors developing prenatal practice guidelines at both the provincial and national levels.

Prenatal screening for fetal aneuploidy in singleton pregnancies.

OBJECTIVE: To develop a Canadian consensus document on maternal screening for fetal aneuploidy (e.g., Down syndrome and trisomy 18) in singleton pregnancies. OPTIONS: Pregnancy screening for fetal aneuploidy started in the mid 1960s, using maternal age as the screening test. New developments in maternal serum and ultrasound screening have made it possible to offer all pregnant patients a non-invasive screening test to assess their risk of having a fetus with aneuploidy to determine whether invasive prenatal diagnostic testing is necessary. This document reviews the options available for non-invasive screening and makes recommendations for Canadian patients and health care workers. OUTCOMES: To offer non-invasive screening for fetal aneuploidy (trisomy 13, 18, 21) to all pregnant women. Invasive prenatal diagnosis would be offered to women who screen above a set risk cut-off level on non-invasive screening or to pregnant women whose personal, obstetrical, or family history places them at increased risk. Currently available non-invasive screening options include maternal age combined with one of the following: (1) first trimester screening (nuchal translucency, maternal age, and maternal serum biochemical markers), (2) second trimester serum screening (maternal age and maternal serum biochemical markers), or (3) 2-step integrated screening, which includes first and second trimester serum screening with or without nuchal translucency (integrated prenatal screen, serum integrated prenatal screening, contingent, and sequential). These options are reviewed, and recommendations are made. EVIDENCE: Studies published between 1982 and 2009 were retrieved through searches of PubMed or Medline and CINAHL and the Cochrane Library, using appropriate controlled vocabulary and key words (aneuploidy, Down syndrome, trisomy, prenatal screening, genetic health risk, genetic health surveillance, prenatal diagnosis). Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. There were no language restrictions. Searches were updated on a regular basis and incorporated in the guideline to August 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The previous Society of Obstetricians and Gynaecologists of Canada guidelines regarding prenatal screening were also reviewed in developing this clinical practice guideline. VALUES: The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS: This guideline is intended to reduce the number of prenatal invasive procedures done when maternal age is the only indication. This will have the benefit of reducing the numbers of normal pregnancies lost because of complications of invasive procedures. Any screening test has an inherent false-positive rate, which may result in undue anxiety. It is not possible at this time to undertake a detailed cost-benefit analysis of the implementation of this guideline, since this would require health surveillance and research and health resources not presently available; however, these factors need to be evaluated in a prospective approach by provincial and territorial initiatives. RECOMMENDATIONS 1. All pregnant women in Canada, regardless of age, should be offered, through an informed counselling process, the option of a prenatal screening test for the most common clinically significant fetal aneuploidies in addition to a second trimester ultrasound for dating, assessment of fetal anatomy, and detection of multiples. (I-A) 2. Counselling must be non-directive and must respect a woman's right to accept or decline any or all of the testing or options offered at any point in the process. (III-A) 3. Maternal age alone is a poor minimum standard for prenatal screening for aneuploidy, and it should not be used a basis for recommending invasive testing when non-invasive prenatal screening for aneuploidy is available. (II-2A) 4. Invasive prenatal diagnosis for cytogenetic analysis should not be performed without multiple marker screening results except for women who are at increased risk of fetal aneuploidy (a) because of ultrasound findings, (b) because the pregnancy was conceived by in vitro fertilization with intracytoplasmic sperm injection, or (c) because the woman or her partner has a history of a previous child or fetus with a chromosomal abnormality or is a carrier of a chromosome rearrangement that increases the risk of having a fetus with a chromosomal abnormality. (II-2E) 5. At minimum, any prenatal screen offered to Canadian women who present for care in the first trimester should have a detection rate of 75% with no more than a 3% false-positive rate. The performance of the screen should be substantiated by annual audit. (III-B) 6. The minimum standard for women presenting in the second trimester should be a screen that has a detection rate of 75% with no more than a 5% false-positive rate. The performance of the screen should be substantiated by annual audit. (III-B) 7. First trimester nuchal translucency should be interpreted for risk assessment only when measured by sonographers or sonologists trained and accredited for this service and when there is ongoing quality assurance (II-2A), and it should not be offered as a screen without biochemical markers in singleton pregnancies. (I-E) 8. Evaluation of the fetal nasal bone in the first trimester should not be incorporated as a screen unless it is performed by sonographers or sonologists trained and accredited for this service and there is ongoing quality assurance. (II-2E) 9. For women who undertake first trimester screening, second trimester serum alpha fetoprotein screening and/or ultrasound examination is recommended to screen for open neural tube defects. (II-1A) 10. Timely referral and access is critical for women and should be facilitated to ensure women are able to undergo the type of screening test they have chosen as first trimester screening. The first steps of integrated screening (with or without nuchal translucency), contingent, or sequential screening are performed in an early and relatively narrow time window. (II-1A) 11. Ultrasound dating should be performed if menstrual or conception dating is unreliable. For any abnormal serum screen calculated on the basis of menstrual dating, an ultrasound should be done to confirm gestational age. (II-1A) 12. The presence or absence of soft markers or anomalies in the 18- to 20-week ultrasound can be used to modify the a priori risk of aneuploidy established by age or prior screening. (II-2B) 13. Information such as gestational dating, maternal weight, ethnicity, insulin-dependent diabetes mellitus, and use of assisted reproduction technologies should be provided to the laboratory to improve accuracy of testing. (II-2A) 14. Health care providers should be aware of the screening modalities available in their province or territory. (III-B) 15. A reliable system needs to be in place ensuring timely reporting of results. (III-C) 16. Screening programs should be implemented with resources that support audited screening and diagnostic laboratory services, ultrasound, genetic counselling services, patient and health care provider education, and high quality diagnostic testing, as well as resources for administration, annual clinical audit, and data management. In addition, there must be the flexibility and funding to adjust the program to new technology and protocols. (II-3B).

Prenatal screening for and diagnosis of aneuploidy in twin pregnancies.

OBJECTIVE: To provide a Canadian consensus document with recommendations on prenatal screening for and diagnosis of fetal aneuploidy (e.g., Down syndrome and trisomy 18) in twin pregnancies. OPTIONS: The process of prenatal screening and diagnosis in twin pregnancies is complex. This document reviews the options available to pregnant women and the challenges specific to screening and diagnosis in a twin pregnancy. OUTCOMES: Clinicians will be better informed about the accuracy of different screening options in twin pregnancies and about techniques of invasive prenatal diagnosis in twins. EVIDENCE: PubMed and Cochrane Database were searched for relevant English and French language articles published between 1985 and 2010, using appropriate controlled vocabulary and key words (aneuploidy, Down syndrome, trisomy, prenatal screening, genetic health risk, genetic health surveillance, prenatal diagnosis, twin gestation). Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to August 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The previous Society of Obstetricians and Gynaecologists of Canada guidelines regarding prenatal screening were also reviewed in developing this clinical practice guideline. VALUES: The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). BENEFITS, HARMS, AND COSTS: There is a need for specific guidelines for prenatal screening and diagnosis in twins. These guidelines should assist health care providers in the approach to this aspect of prenatal care of women with twin pregnancies. SUMMARY STATEMENTS 1. Fetal nuchal translucency combined with maternal age is an acceptable first trimester screening test for aneuploidies in twin pregnancies. (II-2) 2. First trimester serum screening combined with nuchal translucency may be considered in twin pregnancies. It provides some improvement over the performance of screening by nuchal translucency and maternal age by decreasing the false-positive rate. (II-3) 3. Integrated screening with nuchal translucency plus first and second trimester serum screening is an option in twin pregnancies. Further prospective studies are required in this area, since it has not been validated in prospective studies in twins. (III) 4. Non-directive counselling is essential when invasive testing is offered. (III) 5. When chorionic villus sampling is performed in non-monochorionic multiple pregnancies, a combination of transabdominal and transcervical approaches or a transabdominal only approach appears to provide the best results to minimize the likelihood of sampling errors. (II-2) Recommendations 1. All pregnant women in Canada, regardless of age, should be offered, through an informed counselling process, the option of a prenatal screening test for the most common clinically significant fetal aneuploidies. In addition, they should be offered a second trimester ultrasound for dating, assessment of fetal anatomy, and detection of multiples. (I-A) 2. Counselling must be non-directive and must respect a woman's right to accept or decline any or all of the testing or options offered at any point in the process. (III-A) 3. When non-invasive prenatal screening for aneuploidy is available, maternal age alone should not be an indication for invasive prenatal diagnosis in a twin pregnancy. (II-2A) If non-invasive prenatal screening is not available, invasive prenatal diagnosis in twins should be offered to women aged 35 and over. (II-2B) 4. Chorionicity has a major impact on the prenatal screening process and should be determined by ultrasound in the first trimester of all twin pregnancies. (II-2A) 5. When screening is done by nuchal translucency and maternal age, a pregnancy-specific risk should be calculated in monochorionic twins. In dichorionic twins, a fetus-specific risk should be calculated. (II-3C) 6. During amniocentesis, both amniotic sacs should be sampled in monochorionic twin pregnancies, unless monochorionicity is confirmed before 14 weeks and the fetuses appear concordant for growth and anatomy. (II-2B) 7. Prior to invasive testing or in the context of twins discordant for an abnormality, selective reduction should be discussed and made available to those requesting the procedure after appropriate counselling. (III-B) 8. Monitoring for disseminated intravascular coagulopathy is not indicated in dichorionic twin pregnancies undergoing selective reduction. (II-2B).

Incremental cost of non-invasive prenatal diagnosis versus invasive prenatal diagnosis of fetal sex in England.

OBJECTIVES: Fetal sex determination is performed for women who carry X-linked conditions, for example Duchenne muscular dystrophy (DMD), or those associated with ambiguous genitalia, for example congenital adrenal hyperplasia (CAH). Non-invasive prenatal diagnosis (NIPD) using cell-free fetal DNA (cffDNA) in maternal plasma is an alternative to invasive prenatal diagnosis (IPD), which carries a 1% risk of miscarriage. This study aimed to evaluate the incremental cost of NIPD compared with IPD of fetal sex. METHODS: Diagnostic accuracy, invasive testing rate, and pregnancy outcome following NIPD were ascertained from an audit of all cases referred to two laboratories in 2006 to 2009. Care pathways for DMD and CAH were established and key cost drivers for IPD and NIPD identified using costs derived from published estimates and local laboratory values. RESULTS: The differences in mean costs per pregnancy for NIPD versus IPD were small for DMD [mean difference - £87, 95% confidence interval (CI) - £303 to £131] and CAH (-£193, 95% CI - £301 to - £84). Testing costs associated with NIPD were offset by fewer women requiring invasive testing. CONCLUSIONS: The costs of NIPD and IPD of fetal sex are similar. NIPD can provide benefits for many women by avoiding the risks of invasive testing, without incurring additional costs.

[Assessment of anxiety, pain and its management in prenatal diagnosis procedures]. / Évaluation de l'anxiété, de la douleur, et de leur prise en charge dans les gestes de diagnostic anténatal.

UNLABELLED: Invasive prenatal diagnosis procedures are numerous and more or less painful and stressful. The purpose of this study was to investigate maternal perception of both anxiety and pain before and after amniocentesis (AC) or transabdominal chorionic villus sampling (CVS), to determine factors associated with pain and anxiety, and to evaluate the pain support. This is a prospective study evaluating the professional practices at CHRU of Lille between March and May 2009 with 132 AC and 22 CVS by aspiration. An original questionnaire has been elaborated in three parts: the first one fulfilled by patients before the procedure, the second one, after the procedure, and the last one by the medical team. Statistical comparisons have used the Chi(2) test, the Fisher exact test, the Student's t test and the U test of Mann Whitney. RESULTS: The anxiety level is high but does not differ between the two groups AC and CVS. CVS are more painful than AC (EVA 5.77 versus 3.07, P<0.0001). No predisposing factor for anxiety has been found. On the other side, procedures are more painful when they are long lasting, considered difficult by the medical team, when needles used are large, the number of needle insertions increases, puncture is performed along a side of the uterus, patients are anxious, and then procedure indication is an hygroma. Patients are satisfied in 98.7% of cases of the support of the medical team. Few drug treatments was prescribed (only 4.5%), however, patients are generally applicant. CONCLUSION: An analgesic, anxiolytic, or a relaxation technique can be proposed to anxious and applicant patients undergoing CVS. Technical conditions of the procedure are more difficult to improve, however, we should use if possible thinner needles, and avoid, wherever technically possible, the punctures on the lateral side of the uterus. Finally, further studies seem necessary for the evaluation of a treatment protocol.

Consumerism in prenatal diagnosis? A local Italian study.

AIM: To assess the causes of excessive use of prenatal diagnosis. MATERIAL AND METHODS: 304 questionnaires were completed anonymously by puerperae in a Siena (Italy) hospital in May-August 2006. The questionnaires contained 24 questions about the women, examinations performed during pregnancy and the reasons for them. RESULTS: The mean number of ultrasound examinations per woman was 6.5 +/- 2.5. Forty-two percent of the women in our sample (29.3% of women under 35 and 68.9% of women over 35 years of age) reported that amniocentesis/CVS had been performed; the mean age of these women was 34.1 +/- 4.5 years. Eighty-five percent of the women under 36 years of age who had amniocentesis declared that it was performed as a personal choice and 15% for the presence of risk factors. Among 131 women who performed amniocentesis, 32 performed it with a normal blood screening for Down syndrome (DS), and 76 declared to have performed no blood screening for DS. Only 45% of women stated that they thought age above 35 years was a risk factor for pregnancy, but most of them (75%) were aware that amniocentesis was performed to detect chromosomal anomalies. In 89% of the cases a source of information about prenatal testing was the woman's gynecologist. CONCLUSION: This study shows that the high use of prenatal examinations is often not justified by the presence of clinical risk factors and that both national health system and caregivers should find new strategies to inform women about the aims of prenatal tests, and promote a more serene approach to pregnancy. A broader study is needed to confirm these data.