Women's knowledge of and attitudes to first and second trimester screening for Down's syndrome

First Trimester Tricuspid Regurgitation: Clinical Significance

Tricuspid regurgitation is a cardiac valvular anomaly that consists of the return of blood to the right atrium during systole due to incomplete valve closure. This structure can be visualized on ultrasound between 11 and 14 weeks of gestation in most cases. Despite being a common finding, even in healthy fetuses, the presence of tricuspid regurgitation may be associated with chromosomal and structural abnormalities. The evaluation of tricuspid flow and the presence of regurgitation on first-trimester ultrasound has shown promising results regarding its role in the early detection of aneuploidies, congenital heart defects, and other adverse perinatal outcomes. This review article aims to demonstrate the importance of tricuspid regurgitation as a secondary marker, and consequently, significant benefits of its early detection when added to the combined first-trimester screening. Its value will be discussed, namely its sensitivity and specificity, alone and together with other current markers in the fetal assessment performed in the first-trimester ultrasound.

Psychological outcomes, knowledge and preferences of pregnant women on first-trimester screening for fetal structural abnormalities: A prospective cohort study

INTRODUCTION

The primary aim of this study is to investigate the impact of a 13-week anomaly scan on the experienced levels of maternal anxiety and well-being. Secondly, to explore women's knowledge on the possibilities and limitations of the scan and the preferred timing of screening for structural abnormalities.

MATERIAL AND METHODS

In a prospective-cohort study conducted between 2013-2015, pregnant women in the North-Netherlands underwent a 13-week anomaly scan. Four online-questionnaires (Q1, Q2, Q3 and Q4) were completed before and after the 13- and the 20-week anomaly scans. In total, 1512 women consented to participate in the study and 1118 (74%) completed the questionnaires at Q1, 941 (64%) at Q2, 807 (55%) at Q3 and 535 (37%) at Q4. Psychological outcomes were measured by the state-trait inventory-scale (STAI), the patient's positive-negative affect (PANAS) and ad-hoc designed questionnaires.

RESULTS

Nine-nine percent of women wished to be informed as early as possible in pregnancy about the absence/presence of structural abnormalities. In 87% of women levels of knowledge on the goals and limitations of the 13-week anomaly scan were moderate-to-high. In women with a normal 13-week scan result, anxiety levels decreased (P < .001) and well-being increased over time (P < .001). In women with false-positive results (n = 26), anxiety levels initially increased (STAI-Q1: 39.8 vs. STAI-Q2: 48.6, P = 0.025), but later decreased around the 20-week anomaly scan (STAI-Q3: 36.4 vs. STAI-Q4: 34.2, P = 0.36).

CONCLUSIONS

The 13-week scan did not negatively impact the psychological well-being of pregnant women. The small number of women with screen-positive results temporarily experienced higher anxiety after the scan but, in false-positive cases, anxiety levels normalized again when the abnormality was not confirmed at follow-up scans. Finally, most pregnant women have moderate-to-high levels of knowledge and strongly prefer early screening for fetal structural abnormalities.

Crash sign: new first-trimester sonographic marker of spina bifida

OBJECTIVES

To describe a new first-trimester sonographic sign, the 'crash sign', associated with fetal open spina bifida, and to evaluate its clinical usefulness in the first-trimester diagnosis of spina bifida.

METHODS

This was a retrospective review of patients referred to three fetal medicine centers in the first trimester (11 + 0 to 13 + 6 weeks) with suspected spina bifida. Spina bifida was confirmed by direct visualization of the spinal defect on ultrasound by two experts and, when possible, by fetal postmortem examination. Ultrasound images were reviewed for the presence of the crash sign, which is the posterior displacement of the mesencephalon and deformation against the occipital bone in the axial view. The first-trimester ultrasound images of a mixed group of 10 cases and 40 control fetuses without spina bifida were assessed for the presence of the crash sign by two assessors blinded to the diagnosis.

RESULTS

The crash sign was present in 48 out of 53 confirmed cases of spina bifida. Of these, 27 had isolated spina bifida and 21 had an associated anomaly. Of the five cases without the crash sign, one had isolated spina bifida and four had an associated anomaly. The crash sign was not reported in any of the control fetuses.

CONCLUSIONS

We have described a new first-trimester sonographic marker for the diagnosis of spina bifida. Our results suggest that the crash sign may be a useful tool in the first-trimester detection of spina bifida. Prospective evaluation of the crash sign would be beneficial, ideally in a routine clinical screening ultrasound setting. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Relationship between first trimester nuchal septations and chromosomal anomalies

OBJECTIVES

This study aimed to evaluate the association of nuchal septations with chromosomal anomalies during the first trimester of pregnancy.

METHODS

A total of 281 patients who were diagnosed to have elevated nuchal translucency (NT > 3 mm) or nuchal septations during the first trimester from Jan. 2014 to Dec. 2016 were included. These patients were divided into three groups: 1) patients with NT thickness between 3 and 5 mm and without nuchal septations (NT 3-5 mm group, n = 124), 2) patients with NT thickness > 5 mm and without nuchal septations (NT > 5 mm group, n = 96), and 3) patients with nuchal septations (NS group, n = 61).

RESULTS

The rate of chromosomal abnormalities was significantly higher for patients in NS group compared to those in the NT 3-5 mm group (P < .01) and NT > 5 mm group (P < .01). After controlling for maternal age, maternal BMI, ethnicity and crown-rump length, nuchal septations were reported to be significantly associated with a higher risk of chromosomal anomalies compared with NT 3-5 mm (OR = 4.97; 95% CI: 2.76-10.77; P < .01) and NT > 5 mm (OR = 3.82; 95% CI: 1.87-7.21; P < .01) (P < .01).

CONCLUSIONS

Measurement of nuchal septations during the first trimester of pregnancy proves to be a useful ultrasound prognostic indicator of chromosomal anomalies.

Association between timing of diagnosis of trisomy 21, 18, and 13 and maternal socio-economic status in Victoria, Australia: A population-based cohort study from 2015 to 2016

OBJECTIVES

To explore the association between timing of diagnosis of common autosomal trisomies, maternal age, and socio-economic status (SES).

DESIGN

Retrospective study of cytogenetic diagnoses of trisomy 21 (T21), trisomy 18 (T18), and trisomy 13 (T13) in Victoria, Australia, in 2015 to 2016, stratified by timing (prenatal less than 17 weeks gestation, prenatal including or greater than or 17 weeks gestation, and postnatal before 12 months of age), maternal age, and SES region. Utilisation of prenatal testing following a live-born T21 infant was ascertained via record linkage.

RESULTS

Among 160 230 total births were 571 diagnoses of T21 and 246 of T18/T13. The overall and live birth prevalences of T21 were 3.56 and 0.47 per 1000 births, respectively. Compared with women from disadvantaged SES regions, women from high SES regions were more likely to have a prenatal diagnosis of a trisomy before 17 weeks than after (P < .01) and less likely to have a live-born T21 infant than a prenatal diagnosis (P < .01). There was a significant trend to higher live birth rates of T21 with lower SES (P = .004). The majority (68.5%) of women who gave birth to a live infant with T21 did not utilise prenatal testing.

CONCLUSION

There is a significant relationship between lower SES, later prenatal diagnosis of trisomy, and higher live birth rate of T21 in Victoria.

Employ ductus venous blood flow in the early detection of trisomy 21, trisomy 18, and trisomy 13: A meta-analysis

BACKGROUND AND OBJECTIVE

Ductus venosus (DV) Doppler has been suggested as a biomarker for the early screening of trisomy diseases. However, results from different studies have been largely inconsistent. This study aimed to investigate the relationship between DV and top 3 fetal aneuploidies by a systematical meta-analysis: trisomy 21 (T21), trisomy 18 (T18), and trisomy 13 (T13).

METHODS

We performed a literature search covering articles from Medline, PubMed, RePORTER, and Elsevier publications. DV-T21/T18/T13 relation data were extracted from 9, 7, and 6 previous studies, respectively, including 31,053, 28,092 and 26,721 pregnant women worldwide. Both random-effects and fixed-effect model were used to study the log odds ratio (LOR) of T21, T18, and T13 in case of DV. Four potential influential factors were studied using a multiple linear regression (MLR) model, including maternal age, data age, sample size, and population region.

RESULTS

DV was significantly related to T21, T18, and T13 (LOR = 3.44, 3.89 and 3.46; P value <2.1E-13). Significant between-study variance was observed for T21 (P value <1.71E-14), but not for T18 (P value >.05) and T13 (P value >.87). MLR results suggested that significant influential factors could include population region (P value <.0021), but not sample size, data age, and maternal age (P value >.078).

CONCLUSIONS

Integrating DV could help in the detection of trisomy. However, accuracy and validity may vary depending on the population regions, which need further study.

[Birth of a child with Down syndrome: parental choice or failure of screening policy?]

OBJECTIVES

Birth of a child with Down syndrome (DS) can follow parental choice or failure of screening. The objective of this work is to describe the circumstances of births of children with DS in a French perinatal health network.

METHODS

Retrospective multicentric study, with prospective trial registration of all children born alive with DS, between 2010 and 2013.

RESULTS

Sixty-three children were born with DS. Complete screening was performed by 61 % of patients, incomplete screening by 29 % of patients and no screening test by 10 %. Among these births, 50 % occurred following parental choice, 40 % following failure of screening and for 10 %, parental choice concerning screening was unknown. False negative had often calculating risk close to 1/1000.

CONCLUSION

In this study, the birth of a child with DS occurred following parental choice in half of cases. It's necessary, to optimize the follow-up, to document in medical records the medical information and parental choice concerning DS screening and data of screening when this was done.

Nichtinvasive Pränataldiagnostik

Das Ersttrimesterscreening zur Risikobestimmung für die Trisomien 21, 18 und 13 hat sich in den letzten 15 Jahren in Deutschland etabliert. Die optimale Durchführung setzt die Einhaltung bestimmter Messkriterien beim Ultraschall und bei der biochemischen Analyse voraus sowie die Benutzung evaluierter Risikoberechnungsprogramme wie dem Berechnungsprogramm PRC der Fetal Medicine Foundation Deutschland (FMF-D). Durch die neue Version des Berechnungsprogramms PRC konnten die Trisomie-21-, -18- und -13-Detektionsraten erhöht werden bei gleichzeitiger Senkung der Falsch-positiv-Raten, was einen großen Fortschritt verglichen mit der mütterlichen Altersindikation darstellt.

Durch die Analyse der zellfreien fetalen DNA aus dem mütterlichen Plasma können seit 2 Jahren aber wesentlich bessere Screeningvorhersagen getroffen werden. Über 99 % aller Trisomie-21-Schwangerschaften können mit dieser Methodik als Risikogruppe beschrieben werden. Die Falsch-positiv-Rate liegt unter 1 %. Durch diese Methode ist ein Paradigmenwechsel in der Pränataldiagnostik zu erwarten.

First Trimester Ultrasound in Prenatal Diagnosis-Part of the Turning Pyramid of Prenatal Care

First-trimester sonographic assessment of the risk of chromosomal abnormalities is routinely performed throughout the world, primarily by measuring fetal nuchal translucency thickness between 11–13 weeks’ gestation, combined with assessment of serum markers. The development of high-frequency transvaginal transducers has led to improved ultrasound resolution and better visualization of fetal anatomy during the first-trimester. Continuous improvement in ultrasound technology allows a thorough detailed assessment of fetal anatomy at the time of the nuchal translucency study. Using transabdominal or transvaginal sonography, or a combination of both approaches, it is now possible to diagnose a wide range of fetal anomalies during the first trimester. Multiple studies reported early diagnosis of major fetal anomalies after demonstrating the association of increased nuchal translucency thickness with structural defect in chromosomally normal and abnormal fetuses. Normal sonographic findings provide reassurance for women at high risk while detection of fetal malformation during the first trimester enables discussion and decisions about possible treatments and interventions, including termination of pregnancy, during an early stage of pregnancy.

Extended First-Trimester Screening Using Multiple Sonographic Markers and Maternal Serum Biochemistry: A Five-Year Prospective Study

<b><i>Objective:</i></b> To examine the performance of first-trimester screening test combining several fetal sonographic and maternal biochemical markers for major aneuploidy in a Chinese population. <b><i>Methods:</i></b> This was a prospective study performed over 5 years between January 2005 and December 2010 in Taiwan, with 20,586 cases that had a combination of a variety of sonographic markers and maternal serological β-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels assessed at first trimester screening between 11⁺⁰ and 13⁺⁶ weeks of gestation. The risk of aneuploidy was calculated using algorithm software developed by Fetal Medicine Foundation, London. Fetal karyotyping was performed when the prenatal screening showed a risk of 1/300 or higher. All cases were followed for fetal outcome. <b><i>Results:</i></b> The study population was divided into four groups according to the screening strategy performed. The combination of maternal serological biochemistry and nuchal translucency measurement had a 66.7% detection rate of trisomy 21. Addition of nasal bone status increased the detection rate of trisomy 21 to 88.2%. Inclusion of tricuspid regurgitation flow showed an 87.5% detection rate of trisomy 21. Further inclusion of ductus venosus flow increased the detection rate of trisomy 21 to 100%. Incorporating more markers greatly increased the detection rate and decreased the false-positive rate (FPR). <b><i>Conclusion:</i></b> Extension of first-trimester screening to include more sonographic markers greatly increased the sensitivity and decreased FPR for detection of chromosomal abnormalities. Such screening strategy is effective in clinical practice for the Chinese ethnic population.

Implementation of maternal blood cell-free DNA testing in early screening for aneuploidies

OBJECTIVE

To explore the feasibility of routine maternal blood cell-free (cf) DNA testing in screening for trisomies 21, 18 and 13 at 10 weeks' gestation.

METHOD

In this prospective study, women attending The Fetal Medicine Centre in London, UK, between October 2012 and April 2013, with singleton pregnancy and live fetus with CRL 32-45 mm, were screened for trisomies 21, 18 and 13 by cfDNA testing at 10 weeks and the combined test at 12 weeks.

RESULTS

cfDNA testing was performed in 1005 singleton pregnancies with a median maternal age of 37 (range, 20-49) years. Risks for trisomies were provided for 957 (95.2%) cases and in 98.0% these were available within 14 days from sampling. In 48 (4.8%) cases no result was provided due to problems with delivery to the laboratory, low fetal fraction or assay failure. Repeat sampling was performed in 40 cases and a result obtained in 27 (67.5%) of these. In 11 cases the risk score for trisomy 21 and in five cases that for trisomy 18 was > 99%, in one the risk for trisomy 13 was 34% and in 968 the risk for each of the three trisomies was < 0.01%. The suspected trisomies were confirmed by karyotyping after chorionic villus sampling (CVS), except in one case of trisomy 18 in which the karyotype was normal. On the basis of the maternal age distribution of the study population, the expected and observed numbers for each of the three trisomies were similar. Both cfDNA and combined testing detected all trisomies, but the estimated false-positive rates (FPR) were 0.1% and 3.4%, respectively.

CONCLUSION

Routine screening for trisomies 21, 18 and 13 by cfDNA testing at 10 weeks is feasible and has a lower FPR than does combined testing, but abnormal results require confirmation by CVS.

First-trimester screening for chromosomal abnormalities by integrated application of nuchal translucency, nasal bone, tricuspid regurgitation and ductus venosus flow combined with maternal serum free β-hCG and PAPP-A: a 5-year prospective study

OBJECTIVE

To investigate the performance of first-trimester screening for chromosomal abnormalities by integrated application of nuchal translucency thickness (NT), nasal bone (NB), tricuspid regurgitation (TR) and ductus venosus (DV) flow combined with maternal serum free β-human chorionic gonadotropin (fβ-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at a one-stop clinic for assessment of risk (OSCAR).

METHODS

In total, 13,706 fetuses in 13,437 pregnancies were screened for chromosomal abnormalities during a period of 5 years. Maternal serum biochemical markers and maternal age were evaluated in combination with NT, NT + NB, NT + NB + TR, and NT + NB + TR + DV flow data in 8581, 242, 236 and 4647 fetuses, respectively.

RESULTS

In total, 51 chromosomal abnormalities were identified in the study population, including 33 cases of trisomy 21, eight of trisomy 18, six of sex chromosome abnormality, one of triploidy and three of other unbalanced abnormalities. The detection rate and false-positive rate (FPR) for trisomy 21 were 93.8% and 4.84%, respectively, using biochemical markers and NT, and 100% and 3.4%, respectively, using biochemical markers, NT, NB, TR and DV flow.

CONCLUSION

While risk assessment using combined biochemical markers and NT measurement has an acceptable screening performance, it can be improved by the integrated evaluation of secondary ultrasound markers of NB, TR and DV flow. This enhanced approach would decrease the FPR from 4.8 % to 3.4 %, leading to a lower number of unnecessary invasive diagnostic tests and subsequent complications, while maintaining the maximum level of detection rate. Pre- and post-test genetic counseling is of paramount importance in either approach.

Parental duties and prenatal screening: does an offer of prenatal screening lead women to believe that they are morally compelled to test?

BACKGROUND

in debates around prenatal screening, it is frequently argued that responsible parenthood implies the acquisition of all available medical information about the health of a fetus, and use of this information to benefit the future child.

OBJECTIVE

to analyse whether an offer of a prenatal test leads women to believe that they are morally obliged to control the health of their fetus.

DESIGN

a substudy within a randomised controlled trial (RCT) aimed to assess the decision-making process of women when confronted with an offer of a prenatal screening test.

PARTICIPANTS

111 women participating in an RCT were retrospectively asked their views on the meaning of testing within their parental duties.

FINDINGS

testing was described as a personal option that goes beyond the normal parental responsibilities. Participants did not believe that they ought to control the health of the fetus or to avoid disability. A duty to test was only reported when the birth of a disabled child would have a negative impact on family life.

CONCLUSION

women's accounts suggest that two main factors are involved in making testing morally obligatory: (1) the woman's views on her moral duties to her family; and (2) the expected burden of a disabled child on the well-being of the family. A family-centred approach would be more suitable to assess the moral imperative character of testing than women's ethical views about their moral duties towards their unborn child.

IMPLICATIONS

a test offer should not be limited to communication of the characteristics of screening and the meaning of the test results. In helping women to assess the meaning of testing within their parental duties, counselling should include the family situation in which women have to decide, the women's expectations about living with a child with Down's syndrome or any other disability, and the women's views on their commitments towards their family.

Patient and provider attitudes toward screening for Down syndrome in a Latin American country where abortion is illegal

OBJECTIVE

To examine patient and provider attitudes toward first trimester nuchal translucency (NT) screening for Down syndrome and to assess how patients consent to screening in a country where abortion is illegal.

METHODS

Patients presenting for first trimester ultrasound including NT screening in two obstetric units in Chile completed a questionnaire about their attitudes toward NT screening and perspectives on the consent process. A follow-up questionnaire assessed satisfaction with the test. Prenatal care providers also completed a questionnaire ascertaining their perspectives on NT screening.

RESULTS

A total of 107 patients completed the initial questionnaire and 78 completed the follow-up questionnaire. Although 98 (94%) patients desired NT screening only 38 (38%) indicated that they would undergo diagnostic testing if they received screen positive results. Only 3 patients screened positive; however, 15 (20%) participants experienced increased anxiety after the test. Almost all of the 36 providers surveyed indicated that they counsel their patients thoroughly, but 38 (39%) patients reported that they received adequate information.

CONCLUSION

NT screening is often performed without patients' full understanding of the implications of potential results and may cause anxiety. Providers should elicit patients' preferences regarding prenatal testing and engage them in shared decision making about whether to undergo screening, particularly when abortion is not an option.

Options for Down Syndrome Screening: What Will Women Choose?

Down syndrome screening has been offered to pregnant women since the early 1980s. Protocols have changed as research confirmed improvements that result in higher detection rates and lower false-positive rates. Results from 2 clinical trials evaluating screening protocols that include ultrasound measurement of nuchal translucency and biochemical testing in the first and second trimester are now available. First-trimester screening is an option if there are adequate ultrasound, diagnostic, and counseling services available. Regional variation in the availability of these services may limit the implementation of first-trimester screening. Combining screening tests for Down syndrome from both trimesters as an integrated test offers the highest detection rate with the lowest false-positive rate. The possibility of avoiding a positive screen will make this an attractive option for some. Timing, detection rate, false-positive rates, and personal factors influence the decision women make regarding screening versus diagnostic testing. This article reviews the efficacy of current protocols for Down syndrome screening. Accurate information about available screening tests will facilitate informed decisions about screening and testing.

'I want a choice, but I don't want to decide'--a qualitative study of pregnant women's experiences regarding early ultrasound risk assessment for chromosomal anomalies

OBJECTIVE

To increase our understanding of how pregnant women experience early ultrasound examination that includes a risk assessment for chromosomal anomalies and how such women perceive the test results.

DESIGN/SETTING

Qualitative study at St. Olavs Hospital in Norway. Both pre- and post-examination interviews were conducted with ten pregnant women who underwent risk assessment for chromosomal anomalies. Grounded theory was used to analyse the results.

FINDINGS

The study generated a core category (I want a choice, but I don't want to decide), which related to the conflict between choice and decision making. There were also five main categories (existential choices, search for knowledge, anxiety, feeling of guilt and counselling and care). The main categories describe the complex feelings experienced by the women regarding the risk assessment. Factors contributing to the difficulty of choice included loss of control and coping, emotional connection to the fetus and social pressure. As the women sought independent choices without any external influence, they also felt greater responsibility. The women's understanding of the actual risk varied, and they used different types of logic and methods to evaluate the risk and reach a decision.

CONCLUSIONS

The pregnant women in this study wanted prenatal diagnostic information and easy access to specialty services. Stress-related feelings and non-transparent information about the actual and perceived risks as well as personal moral judgments made the decision-making process complicated. Improved distribution of information and frequent contact with health professionals may help such women to make informed choices in accordance with their values and beliefs.

Ethical considerations in first-trimester Down syndrome risk assessment

PURPOSE OF REVIEW

First-trimester risk assessment has now become sophisticated and of increasing relevance and applicability to decision-making by pregnant woman about invasive diagnosis. Ethics is an essential dimension of understanding this relevance and applicability. This paper addresses the ethical dimensions of first-trimester risk assessment for trisomy 21.

RECENT FINDINGS

It is now well established in the ethics and law of the informed consent process that physicians are obligated to offer to patients all medically reasonable alternatives for managing the patient's condition. This disclosure should be guided by the reasonable person standard: the physician should provide clinically important information about the patient's condition or diagnosis, the medically reasonable alternatives for managing it, and the clinical benefits and risks of each such alternative.

SUMMARY

On the basis of the ethics of informed consent, we argue that routinely offering first-trimester risk assessment in centers qualified to provide it is ethically obligatory. We describe how pregnant women can be expected to respond to this offer. We then argue that routinely withholding the results of first-trimester risk assessment is ethically unjustified. The ethics of informed consent is an essential dimension of first-trimester risk assessment for trisomy 21.

Screening for trisomy 18 by maternal age, fetal nuchal translucency, free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A

OBJECTIVES

To derive a model and examine the performance of first-trimester screening for trisomy 18 by maternal age, fetal nuchal translucency (NT) thickness, and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A).

METHODS

Prospective combined screening for trisomy 21 was performed at 11 + 0 to 13 + 6 weeks in 56 893 singleton pregnancies, including 56 376 cases of euploid fetuses, 395 with trisomy 21 and 122 with trisomy 18. The measured free beta-hCG and PAPP-A were converted into a multiple of the median (MoM) and then into likelihood ratios (LR). Similarly, the measured NT was transformed into LRs using the mixture model of NT distributions. In each case the LRs for NT and the biochemical markers were multiplied by the age and gestation-related risk to derive the risk for trisomy 21 and trisomy 18. Detection rates (DRs) and false-positive rates (FPRs) were calculated by taking the proportions with risks above a given risk threshold.

RESULTS

In screening with the algorithm for trisomy 21, at a FPR of 3%, the estimated DRs of trisomies 21 and 18 were 89% and 82%, respectively. The use of an algorithm for trisomy 18 identified 93% of affected fetuses at a FPR of 0.2%. When the algorithm for trisomy 21 was used and screen positivity was fixed at a FPR of 3%, and in addition the algorithm for trisomy 18 was used and screen positivity was fixed at a FPR of 0.2%, the overall FPR was 3.1% and the DRs of trisomies 21 and 18 were 90% and 97%, respectively.

CONCLUSIONS

A beneficial side effect of first-trimester combined screening for trisomy 21 is the detection of a high proportion of fetuses with trisomy 18. If an algorithm for trisomy 18 in addition to the one for trisomy 21 is used, more than 95% of trisomy 18 fetuses can be detected with a minor increase of 0.1% in the overall FPR.

Exploring general practitioners' experience of informing women about prenatal screening tests for foetal abnormalities: a qualitative focus group study

Background

Recent developments have made screening tests for foetal abnormalities available earlier in pregnancy and women have a range of testing options accessible to them. It is now recommended that all women, regardless of their age, are provided with information on prenatal screening tests. General Practitioners (GPs) are often the first health professionals a woman consults in pregnancy. As such, GPs are well positioned to inform women of the increasing range of prenatal screening tests available. The aim of this study was to explore GPs experience of informing women of prenatal genetic screening tests for foetal abnormality.

Methods

A qualitative study consisting of four focus groups was conducted in metropolitan and rural Victoria, Australia. A discussion guide was used and the audio-taped transcripts were independently coded by two researchers using thematic analysis. Multiple coders and analysts and informant feedback were employed to reduce the potential for researcher bias and increase the validity of the findings.

Results

Six themes were identified and classified as 'intrinsic' if they occurred within the context of the consultation or 'extrinsic' if they consisted of elements that impacted on the GP beyond the scope of the consultation. The three intrinsic themes were the way GPs explained the limitations of screening, the extent to which GPs provided information selectively and the time pressures at play. The three extrinsic factors were GPs' attitudes and values towards screening, the conflict they experienced in offering screening information and the sense of powerlessness within the screening test process and the health care system generally. Extrinsic themes reveal GPs' attitudes and values to screening and to disability, as well as raising questions about the fundamental premise of testing.

Conclusion

The increasing availability and utilisation of screening tests, in particular first trimester tests, has expanded GPs' role in facilitating women's informed decision-making. Recognition of the importance of providing this complex information warrants longer consultations to respond to the time pressures that GPs experience. Understanding the intrinsic and extrinsic factors that impact on GPs may serve to shape educational resources to be more appropriate, relevant and supportive.

Ethics is an essential dimension of first-trimester risk assessment for trisomy 21

We identify the clinical implications of the ethics of informed consent for risk assessment for trisomy 21. Based on the ethics of informed consent, we argue that routinely offering first-trimester risk assessment in centers qualified to provide it is ethically obligatory. We describe how pregnant women can be expected to respond to this offer. We then argue that routinely withholding the results of first-trimester risk assessment is ethically unjustified. The ethics of informed consent is an essential dimension of first-trimester risk assessment for trisomy 21.

First trimester ultrasonography in screening and detection of fetal anomalies

An obstetrical ultrasound examination provides invaluable information regarding the fetus. Until the mid-1980s, ultrasound in the first trimester was limited to localization of the pregnancy, establishing viability, and accurate dating. With the advent of high-resolution ultrasound and transvaginal scanning, a significant amount of information about the fetus can be gained and provided to the patient at a very early stage in gestation. This article provides an overview of the role of first trimester (11-13 + 6 weeks' gestation) ultrasound in screening and diagnosis of fetal anomalies. The first trimester is an ideal time for screening for aneuploidy, primarily due to the advantages that nuchal translucency (NT) measurement provides. NT measurement is also useful in establishing the risk of congenital cardiac disorders and a number of genetic and non-genetic syndromes. Significant NT thickening is associated with an increase in perinatal morbidity and mortality. Potential mechanisms resulting in increased NT are discussed. A number of new ultrasound markers for fetal aneuploidy have been investigated over the past several years, some of which appear to improve the screening efficacy of early ultrasonography. The role of these is reviewed. A number of fetal anomalies can now be consistently diagnosed in the first trimester. Their appearance at this early gestational age is discussed as well. It is clear that, data obtained by first trimester ultrasound are useful in counseling expectant parents and in planning the appropriate follow-up.

Ethical considerations of early (first vs. second trimester) risk assessment disclosure for trisomy 21 and patient choice in screening versus diagnostic testing

We discuss the clinical implications regarding disclosure of risk assessment for trisomy 21 screening results in the first versus second trimester. Based on the ethical principles of respect for autonomy, beneficence, and justice, we argue that routinely offering first trimester risk assessment in centers qualified to provide it is ethically obligatory and routinely withholding the results of first trimester risk assessment is ethically unjustified. As risk for trisomy 21 occurs along a continuum, no pregnant woman is without risk; thus, offering diagnostic testing to all women is ethically justified. Informed consent and personal choice regarding diagnostic testing and termination of pregnancy shape patients' decisions to undergo first trimester risk assessment for trisomy 21. Appropriate counseling is required to allow for individual choice regarding timing of disclosure.

Aneuploidy screening in the first trimester

This article reviews the performance of first trimester screening for chromosomal anomalies using various combinations of ultrasound and maternal serum biochemical modalities. Detection rates in excess of 90% can be routinely achieved for Trisomy 21, Trisomy 13, Trisomy 18 using a combination of fetal nuchal translucency (NT) thickness and maternal serum free ss-hCG and PAPP-A at 11 + 0 to 13 + 6 weeks of gestation.

Trends in state/population-based Down syndrome screening and invasive prenatal testing with the introduction of first-trimester combined Down syndrome screening, South Australia, 1995-2005

OBJECTIVE

The purpose of this study was to review trends in the us of maternal serum Down syndrome screening and invasive prenatal testing before and after the introduction of a state-based first-trimester combined Down syndrome screening program.

STUDY DESIGN

A retrospective population-based study was performed on first- and second-trimester Down syndrome screening, invasive prenatal testing, and prenatal detection of Down syndrome from 1995 to 2005 in South Australia with data from state-based registers. Chi-square tests were used to evaluate trends.

RESULTS

There was a significant decrease in the use of second-trimester Down syndrome maternal serum screening (from 75% in 1995 to 25% in 2005; P < .001) and a corresponding significant increase in first-trimester combined screening (from 0.8% in 2000 to 49% in 2005; P < .001). The proportion of all confinements that involved invasive prenatal testing fell (from 9.3% in 1995 to 7.6% in 2005; P < .001). There was a significant decrease in the number of invasive prenatal tests that were needed to detect 1 Down syndrome fetus (from 86 tests in 1995 to 40 tests in 2005; P < .001), with no significant change in the proportion of Down syndrome cases that were detected prenatally.

CONCLUSION

The introduction and increased use of first-trimester combined Down syndrome screening has been associated with more efficient use of invasive prenatal testing in South Australia and has maintained a high level of overall prenatal detection.

Antenatal care implications of population‐based trends in Down syndrome birth rates by rurality and antenatal care provider, Queensland, 1990–2004

OBJECTIVE

To assess whether the rates of Down syndrome births in Queensland vary according to rurality (ie, whether the mother lives in a rural or urban area) and type of antenatal care provider, and to consider any implications for antenatal care.

DESIGN AND SETTING

Population-based study of Down syndrome births in Queensland between 1990 and 2004, stratified by rurality and type of antenatal care provider (private obstetrician, public hospital or shared care).

RESULTS

Since 2000, there has been a large fall in maternal-age-adjusted rates of Down syndrome births among mothers living in urban areas (-14.3% per year; 95% CI, -22.7%, -5.0%) and among mothers receiving their antenatal care from private obstetricians (-27.5% per year; 95% CI, -37.6%, -15.8%). Similar decreases have not occurred among mothers living in rural areas (0.0%; 95% CI, -11.7%, 13.1%) or among mothers receiving antenatal care from public hospitals (+2.9%, 95% CI, -10.3%, 17.9%).

CONCLUSION

Possible reasons for the observed trends include unequal access to antenatal screening; confusion about screening guidelines and protocols; late presentation for antenatal care; and differences in attitudes to screening and termination of pregnancy among expectant parents, such that they may choose not to have screening or not to act on a positive screening test result.

Detection of malformations in chromosomally normal fetuses by routine ultrasound at 12 or 18 weeks of gestation-a randomised controlled trial in 39,572 pregnancies

OBJECTIVE

To compare the antenatal detection rate of malformations in chromosomally normal fetuses between a strategy of offering one routine ultrasound examination at 12 gestational weeks (gws) and a strategy of offering one routine examination at 18 gws.

DESIGN

Randomised controlled trial.

SETTING

Multicentre trial including eight hospitals.

POPULATION

A total of 39,572 unselected pregnant women.

METHODS

Women were randomised either to one routine ultrasound scan at 12 (12-14) gws including nuchal translucency (NT) measurement or to one routine scan at 18 (15-22) gws. Anomaly screening was performed in both groups following a check-list. A repeat scan was offered in the 12-week scan group if the fetal anatomy could not be adequately seen at 12-14 gws or if NT was >or=3.5 mm in a fetus with normal or unknown chromosomes.

MAIN OUTCOME MEASURES

Antenatal detection rate of malformed fetuses.

RESULTS

The antenatal detection rate of fetuses with a major malformation was 38% (66/176) in the 12-week scan group and 47% (72/152) in the 18-week scan group (P= 0.06). The corresponding figures for detection at <22 gws were 30% (53/176) and 40% (61/152) (P= 0.07). In the 12-week scan group, 69% of fetuses with a lethal anomaly were detected at a scan at 12-14 gws.

CONCLUSIONS

None of the two strategies for prenatal diagnosis is clearly superior to the other. The 12-week strategy has the advantage that most lethal malformations will be detected at <15 gws, enabling earlier pregnancy termination. The 18-week strategy seems to be associated with a slightly higher detection rate of major malformations, although the difference was not statistically significant.

Informed choice in women attending private clinics to undergo first-trimester screening for Down syndrome

OBJECTIVES

Informed choice for prenatal screening has long been considered an essential aspect of service provision, and has been researched extensively in the second trimester. This study aims at examining whether women having first-trimester screening in a private clinic had made an informed choice.

METHODS

A cross-sectional survey recruited women having first-trimester screening at specialist ultrasound practices. Two questionnaires containing a validated Multidimensional Measure of Informed Choice (MMIC) were self-administered pre- and post-screening.

RESULTS

MMIC was completed by 81% (163/202) of women. Ninety-nine percent of women had a positive attitude towards screening, therefore informed choice was essentially measured on knowledge alone. Pre-screening, 68% made an informed choice, compared with 74% post-screening (chi2 = 1.6, p = 0.21 (McNemar)). Knowledge was associated with education level, information sources and perception of screening as routine or optional.

CONCLUSIONS

The Australasian Guidelines on prenatal screening state that all women having testing should be provided with written information, and it should be ensured that they have appropriate understanding of the test(s). These guidelines are not being met, even in private clinical care. Health professionals should ensure that all women are provided with suitable information about prenatal screening that is tailored to their level of education and individual needs, and should emphasise that screening is optional.

Screening in women's health, with emphasis on fetal Down's syndrome, breast cancer and osteoporosis

Screening tests have become increasingly popular in women's health care over the last two decades. The initiative for screening is typically generated by either an agency or the health care professional being consulted for some reason. In many instances, however, the demand for screening tests is patient driven with the health care provider being poorly prepared to determine the usefulness of screening. This review illustrates the complexity of screening using three disorders where early detection and treatment have the potential to improve the quality and longevity of life. Prenatal diagnosis of Down's syndrome does not offer the parents the opportunity for cure but does offer the opportunity for education and rational choice as the impact of the diagnosis on the family is weighed. The evidence for breast cancer screening is more persuasive for older than younger women, but even in older women, there is a balance of risks and benefits. Treatment options for osteoporosis have improved in terms of reductions in fracture risk as well as beneficial effects on bone density, but evidence of the effectiveness of a screening programme for this condition in an unselected population is lacking. Ultimately, it is crucial that women be provided with clear and comprehensive information about the screening programme, in terms of possible gains but also costs of various kinds: physical, economic and psychological.

Women's and health professionals' preferences for prenatal testing for Down syndrome in Australia

AIM

To describe and compare women's and health professionals' preferences for prenatal screening tests for Down syndrome.

DESIGN

Cross-sectional questionnaire survey.

PARTICIPANTS AND SETTING

Women (n = 322) attending for a glucose challenge test at 26 weeks gestation and health professionals (266 midwives and 34 obstetricians) at the Royal Women's Hospital, Melbourne, between 13 December 2002 and 30 April 2003.

OUTCOME MEASURES

The relative value participants attach to attributes of Down syndrome screening tests as determined by conjoint analysis and ranking scales.

RESULTS

Women and health professionals shared similar relative values regarding the importance of detection rate of screening tests, according to coefficients from conjoint analysis models. However, health professionals placed higher relative values on timing of prenatal tests and risk associated with the subsequent diagnostic test than did women. Comparison of coefficients suggests that, compared with health professionals, women would wait longer and accept a greater decrease in detection rate for a test if it was safer. Using the more traditional ranking scale, the safest test was ranked first by 56% of women while 47% of health professionals ranked a test with the highest detection rate first. Equal proportions ( approximately 10%) in both groups ranked the earliest test first.

CONCLUSION

There is a general agreement between pregnant women and health professionals regarding the relative importance they attach to different attributes of a test. However, health professionals appeared to favour earlier timing of tests while women placed greater emphasis on safety. Utilising two different measures of preference demonstrated the complexity of decision-making.

Comparing Three Screening Strategies for Combining First- and Second-Trimester Down Syndrome Markers

OBJECTIVE

To describe the choices and tradeoffs inherent in 3 published strategies that combine first- and second-trimester markers for Down syndrome screening.

METHODS

Published marker distributions for Down syndrome and unaffected pregnancies in the first and second trimesters were combined with a maternal age distribution and age-associated Down syndrome risk in a statistical model to compare sequential, contingent, and integrated screening.

RESULTS

Sequential and contingent screening strategies are always less efficient (higher false-positive rate for a given detection rate) than integrated screening, but the reduction in efficiency is dependent on the combination of risk cutoffs chosen. At a fixed false-positive rate, sequential and contingent strategies perform better when a higher proportion of the false positives occur in the second trimester. For all 3 strategies, increasing the overall false-positive rate from 2% to 5% increases detection (from approximately 85% to 91%). Although associated with reduced screening efficiency compared with integrated screening, both sequential and contingent screening identify the majority of detected Down syndrome cases early. With contingent screening, the process is also completed in the first trimester for most women.

CONCLUSION

Integrated screening is the most efficient of the 3 strategies, but it is possible to select risk cutoffs for both sequential and contingent strategies that minimize losses in efficiency while maintaining early detection and early completion. For all of these strategies, well-designed intervention trials are needed to determine acceptability to women and providers in primary care settings and to assess real-world performance.

LEVEL OF EVIDENCE

III.

Testing for Down syndrome in the older woman: a risky business?

For over 30 years, antenatal diagnosis of Down syndrome has been offered on the basis of advanced maternal age. While this was appropriate in the 1970s, developments in antenatal screening have rendered this a most inefficient strategy that is associated with excessive costs and procedure-related pregnancy losses. In this article we argue for a review of how we test for Down syndrome in the older woman.

Community-based screening for Down's Syndrome in the first trimester using ultrasound and maternal serum biochemistry

Two years of community-based first trimester screening (FTS) were audited. All women with singleton pregnancy in a defined health region who completed FTS (ultrasound and biochemistry) were included (n= 10,436) and outcomes obtained for 98.4%. All scans were performed or supervised by experienced sonologists with Fetal Medicine Foundation (FMF) accreditation. FMF software generated all risk assessments based on nuchal translucency (NT), maternal serum-free beta human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein A (PAPP-A). The detection rate for Trisomy 21 was 90.6% with a screen-positive rate of 3.9%. These findings indicate that where FTS is accessible within routine antenatal care, a detection rate of 90% and low screen-positive rate can be achieved using the FMF programme.

Patient preference regarding first-trimester aneuploidy risk assessment

OBJECTIVE

We assessed patient views regarding disclosure of first-trimester Down syndrome risk assessment results compared with withholding results until a single, more accurate second-trimester screening result is available.

STUDY DESIGN

A prospective, institutional review board-approved, voluntary, anonymous survey was presented to patients with singleton pregnancies who were undergoing first-trimester nuchal translucency and biochemical screening at our institution. Options included immediate (sequential testing) or later disclosure (integrated testing). Descriptions and a comparison of the options were included in the survey.

RESULTS

One hundred one women completed the questionnaires; 69.3% of the patients preferred sequential testing, compared with 30.7% of the patients who were either unsure or preferred integrated testing. Older patients and those patients with better background knowledge of screening tests preferred earlier disclosure of screening results (P = .035 and P = .026, respectively). Patients who preferred earlier disclosure also preferred termination of a Down syndrome pregnancy (P = .013).

CONCLUSION

Older patients and those patients with a better understanding of screening tests preferred immediate disclosure of first-trimester risk assessment results; these women were more likely to prefer to terminate an affected pregnancy.

Clinical implications of the ethics of informed consent for first-trimester risk assessment for trisomy 21

OBJECTIVE

We identify the clinical implications of the ethics of informed consent for risk assessment for trisomy 21.

FINDING

Based on the ethics of informed consent, we find that routinely offering first-trimester risk assessment in centers qualified to provide it is ethically obligatory, and routinely withholding the results of first-trimester risk assessment is ethically unjustified.

CONCLUSION

The ethics of informed consent is an essential dimension of first-trimester risk assessment for trisomy 21.

Implementation of first-trimester risk assessment for trisomy 21: ethical considerations

The performance and evaluation of first-trimester risk assessment should meet standards of scientific and ethical excellence. Scientific standards are well understood. Ethical standards are less well understood. On the basis of the ethical concept of the physician as fiduciary, and the ethical principles of respect for autonomy, beneficence, and justice, we show that the obstetrician has an ethical obligation to routinely offer pregnant women first-trimester risk assessment in high quality centers. On the basis of the professional virtues of integrity and self-sacrifice, we then show that both obstetricians and specialists in risk assessment have a strict ethical obligation to identify, responsibly manage, and disclose both economic and noneconomic conflicts of interests, especially when they are hidden. We conclude that ethics is an essential dimension of implementation of first-trimester risk assessment for trisomy 21.

Screening for Down syndrome based on maternal age or fetal nuchal translucency: a randomized controlled trial in 39,572 pregnancies

OBJECTIVES

Nuchal translucency (NT) screening increases antenatal detection of Down syndrome (DS) compared to maternal age-based screening. We wanted to determine if a change in policy for prenatal diagnosis would result in fewer babies born with DS.

METHODS

A total of 39,572 pregnant women were randomized to a scan at 12-14 gestational weeks including NT screening for DS (12-week group) or to a scan at 15-20 weeks with screening for DS based on maternal age (18-week group). Fetal karyotyping was offered if risk according to NT was > or = 1:250 in the 12-week group and if maternal age was > or = 35 years in the 18-week group. Both policies included the offer of karyotyping in cases of fetal anomaly detected at any scan during pregnancy or when there was a history of fetal chromosomal anomaly. The number of babies born with DS and the number of invasive tests for fetal karyotyping were compared.

RESULTS

Ten babies with DS were born alive with the 12-week policy vs. 16 with the 18-week policy (P = 0.25). More fetuses with DS were spontaneously lost or terminated in the 12-week group (45/19,796) than in the 18-week group (27/19 776; P = 0.04). All women except one with an antenatal diagnosis of DS at < 22 weeks terminated the pregnancy. For each case of DS detected at < 22 weeks in a living fetus there were 16 invasive tests in the 12-week group vs. 89 in the 18-week group. NT screening detected 71% of cases of DS for a 3.5% test-positive rate whereas maternal age had the potential of detecting 58% for a test-positive rate of 18%.

CONCLUSIONS

The number of newborns with DS differed less than expected between pregnancies that had been screened at 12-14 weeks' gestation by NT compared with those screened at 15-20 weeks by maternal age. One explanation could be that NT screening--because it is performed early in pregnancy--results in the detection and termination of many pregnancies with a fetus with DS that would have resulted in miscarriage without intervention, and also by many cases of DS being detected because of a fetal anomaly seen on an 18-week scan. The major advantage of the 12-week scan policy is that many fewer invasive tests for fetal karyotyping are needed per antenatally detected case of DS.

Maternal serum pregnancy-associated plasma protein-A and free β-human chorionic gonadotrophin in pregnancies conceived with fresh and frozen-thawed embryos fromin vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

Maternal serum pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotrophin (beta-hCG) are useful markers in the screening of Down syndrome in the first trimester. We investigated the effect of intracytoplasmic sperm injection (ICSI), freezing and thawing of embryos on the levels of these two analytes in assisted reproduction pregnancies.

METHODS

We recruited 149 women who conceived after assisted reproduction with fresh embryos (92 from conventional IVF and 57 from ICSI), 85 women who conceived with frozen-thawed embryos (54 from conventional IVF and 31 from ICSI) and 401 women with spontaneous conceptions as controls. The concentrations of PAPP-A and free beta-hCG were measured between 10 and 14 weeks and were converted to multiples of medians (MoM) for comparisons.

RESULTS

Median PAPP-A MoMs were significantly reduced in ICSI pregnancies in the fresh and frozen-thawed embryo subgroups (0.70 and 0.66 MoM respectively) and in the IVF fresh embryo subgroups (0.83 MoM), as compared to controls (1.00 MoM). Free beta-hCG MoM was significantly reduced in the IVF fresh embryos subgroup (0.87 MoM), but not in the other three subgroups.

CONCLUSION

Further studies for exploring the underlying pathophysiology and adjustment in the marker levels for screening of Down syndrome are warranted in pregnancies conceived after assisted reproduction.