The role of ultrasound in first-trimester screening after the introduction of NIPT as a service of public health insurance - a consensus statement of the Fetal Medicine Foundation (FMF) Germany

Combined first-trimester screening (FTS) and noninvasive prenatal testing (NIPT) have been proven to be reliable noninvasive procedures to detect the most common chromosomal abnormalities (trisomies 21, 18, 13) in the first trimester. The aim of this paper is to demonstrate the strengths and limitations of these two procedures and to give a consensus statement of the Fetal Medicine Foundation (FMF) Germany on how to use the two techniques in the first trimester after the introduction of NIPT as a service of the statutory health insurance companies in Germany.

Fetal arthrogryposis-what do we tell the prospective parents?

Arthrogryposis, also termed arthrogryposis multiplex congenita, is a descriptive term for conditions with multiple congenital contractures (MCC). The etiology is extremely heterogeneous. More than 400 specific disorders have been identified so far, which may lead to or are associated with MCC and/or fetal hypo- and akinesia as a clinical sign. With improved sensitivity of prenatal ultrasound and expanding prenatal diagnostic options, clinicians are tasked with providing early detection in order to counsel the prospective parents regarding further prenatal diagnostic as well as management options. We summarize the most important knowledge to raise awareness for early detection in pregnancy. We review essential points for counseling when MCC is detected in order to provide answers to common questions, which, however, cannot replace interdisciplinary expert opinion in the individual case.

How genomics is changing the practice of prenatal testing

New genomic laboratory technology namely microarrays and high throughput sequencing (HTS) as well as a steady progress in sonographic image capture and processing have changed the practice of prenatal diagnosis during the last decade fundamentally. Pregnancies at high risk for common trisomies are reliably identified by non-invasive prenatal testing (NIPT) and expert sonography has greatly improved the assessment of the fetal phenotype. Preconceptional comprehensive carrier screening using HTS is available for all parents, if they should wish to do so. A definite fetal diagnosis, however, will still require invasive testing for most conditions. Chromosomal microarrays (CMA) have greatly enhanced the resolution in the detection of chromosome anomalies and other causal copy number variations (CNV). Gene panel or whole exome sequencing (WES) is becoming the routine follow up of many anomalies detected by ultrasound after CNVs have been excluded. The benefits and limitations of the various screening as well as diagnostic options are perceived as complex by many who find it challenging to cope with the need for immediate choices. The communication of facts to ensure an informed decision making is obviously a growing challenge with the advent of the new genomic testing options. This contribution provides an overview of the current practice and policies in Switzerland.

Expanding the spectrum of SMAD3-related phenotypes to agnathia-otocephaly

Background

Agnathia‐otocephaly is a rare and lethal anomaly affecting craniofacial structures derived from the first pharyngeal arch. It is characterized by agnathia, microstomia, aglossia, and abnormally positioned auricles with or without associated anomalies. Variants affecting function of OTX2 and PRRX1, which together regulate the neural crest cells and the patterning of the first pharyngeal arch as well as skeletal and limb development, were identified to be causal for the anomaly in a few patients.

Methods

Family‐based exome sequencing (ES) on a fetus with severe agnathia‐otocephaly, cheilognathopalatoschisis, laryngeal hypoplasia, fused lung lobes and other organ abnormalities and mRNA expression analysis were performed.

Results

Exome sequencing detected a de novo SMAD3 missense variant in exon 6 (c.860G>A) associated with decreased mRNA expression. Variants in SMAD3 cause Loeys–Dietz syndrome 3 presenting with craniofacial anomalies such as mandibular hypoplasia, micro‐ or retro‐gnathia, bifid uvula and cleft palate as well as skeletal anomalies and arterial tortuosity.

The SMAD3 protein acts as a transcriptional regulator in the transforming growth factor β (TGFB) and bone morphogenetic (BMP) signaling pathways, which play a key role in the development of craniofacial structures originating from the pharyngeal arches.

Conclusion

Agnathia‐otocephaly with or without associated anomalies may represent the severe end of a phenotypic spectrum related to variants in genes in the interacting SMAD/TGFB/BMP/SHH/FGF developmental pathways.

Fetal arthrogryposis: Challenges and perspectives for prenatal detection and management

Antenatal identification of fetuses with multiple congenital contractures or arthrogryposis multiplex congenita (AMC) may be challenging. The first clinical sign is often reduced fetal movement and/or contractures, as seen on prenatal ultrasounds. This can be apparent at any point, from early to late pregnancy, may range from mild to severe involvement, with or without associated other structural anomalies. Possible etiologies and their prognosis need to be interpreted with respect to developmental timing. The etiology of AMC is highly heterogeneous and making the specific diagnosis will guide prognosis, counseling and prenatal and perinatal management. Current ultrasound practice identifies only approximately 25% of individuals with arthrogryposis prenatally before 24 weeks of pregnancy in a general obstetrics care population. There are currently no studies and guidelines that address the question of when and how to assess for fetal contractures and movements during pregnancy. The failure to identify fetuses with arthrogryposis before 24 weeks of pregnancy means that physicians and families are denied reproductive options and interventions that may improve outcome. We review current practice and recommend adjusting the current prenatal imaging and genetic diagnostic strategies to achieve early prenatal detection and etiologic diagnosis. We suggest exploring options for in utero therapy to increase fetal movement for ongoing pregnancies.

DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures

First-trimester screening between 11 + 0 and 13 + 6 weeks with qualified prenatal counseling, detailed ultrasound, biochemical markers and maternal factors has become the basis for decisions about further examinations. It detects numerous structural and genetic anomalies. The inclusion of uterine artery Doppler and PlGF screens for preeclampsia and fetal growth restriction. Low-dose aspirin significantly reduces the prevalence of severe preterm eclampsia. Cut-off values define groups of high, intermediate and low probability. Prenatal counseling uses detection and false-positive rates to work out the individual need profile and the corresponding decision: no further diagnosis/screening - cell-free DNA screening - diagnostic procedure and genetic analysis. In pre-test counseling it must be recognized that the prevalence of trisomy 21, 18 or 13 is low in younger women, as in submicroscopic anomalies in every maternal age. Even with high specificities, the positive predictive values of screening tests for rare anomalies are low. In the general population trisomies and sex chromosome aneuploidies account for approximately 70 % of anomalies recognizable by conventional genetic analysis. Screen positive results of cfDNA tests have to be proven by diagnostic procedure and genetic diagnosis. In cases of inconclusive results a higher rate of genetic anomalies is detected. Procedure-related fetal loss rates after chorionic biopsy and amniocentesis performed by experts are lower than 1 to 2 in 1000. Counseling should include the possible detection of submicroscopic anomalies by comparative genomic hybridization (array-CGH). At present, existing studies about screening for microdeletions and duplications do not provide reliable data to calculate sensitivities, false-positive rates and positive predictive values.

Exome sequencing of fetal anomaly syndromes: novel phenotype-genotype discoveries

The monogenic etiology of most severe fetal anomaly syndromes is poorly understood. Our objective was to use exome sequencing (ES) to increase our knowledge on causal variants and novel candidate genes associated with specific fetal phenotypes. We employed ES in a cohort of 19 families with one or more fetuses presenting with a distinctive anomaly pattern and/or phenotype recurrence at increased risk for lethal outcomes. Candidate variants were identified in 12 families (63%); in 6 of them a definite diagnosis was achieved including known or novel variants in recognized disease genes (MKS1, OTX2, FGFR2, and RYR1) and variants in novel disease genes describing new fetal phenotypes (CENPF, KIF14). We identified variants likely causal after clinical and functional review (SMAD3, KIF4A, and PIGW) and propose novel candidate genes (PTK7, DNHD1, and TTC28) for early human developmental disease supported by functional and cross-species phenotyping evidence. We describe rare and novel fetal anomaly syndromes and highlight the diagnostic utility of ES, but also its contribution to discovery. The diagnostic yield of the future application of prenatal ES will depend on our ability to increase our knowledge on the specific phenotype–genotype correlations during fetal development.

Fetal Neurosonogaphy: Ultrasound and Magnetic Resonance Imaging in Competition

Both in routine diagnostics and detailed, highly specialized workups, major advances have been observed in many areas of ultrasound due to an increase in expertise and improved technology in recent years. This is particularly true in the case of fetal neurosonography 1 2 3 4. Malformations of the CNS together with fetal heart defects are among the most common congenital anomalies. From the embryonic phase to the late third trimester, the CNS undergoes extensive development and maturation processes. The diagnosis of CNS anomalies is therefore primarily dependent on the time at which the examination is performed and the experience of the examiner. The introduction of transvaginal and 3 D ultrasound for evaluating fetal brain structures has made it possible to diagnose pathological findings of the CNS with increasing accuracy 5. The detection rates for CNS anomalies are up to 90 - 95 % depending on the finding 3 5. Today, detailed fetal neurosonography also includes differential diagnostic evaluation of the posterior cranial fossa, the corpus callosum (CC), and the gyri and therefore exceeds the primarily conspicuous, non-specific diagnosis of "ventricular dilation" often occurring as an accompanying symptom 6 7 The article "Prenatal Diagnosis of Corpus Callosum Anomalies" appearing in this issue shows an increase in the frequency of diagnosis and also shows that it is possible to differentiate between complete and partial corpus callosum agenesis and hypoplasia of the corpus callosum with differentiation between isolated and non-isolated cases is possible on ultrasound. In 4 of 44 cases in which both neurosonography and intrauterine MRI were performed, there was a discrepancy between the ultrasound diagnosis and the intrauterine MRI findings. In a comparison of the sonographic diagnoses and the MRI findings, additional pathologies were seen on MRI but not on ultrasound in only 3 of 44 cases. In a further case of CC hypoplasia, the sonographic diagnosis was superior to the MRI findings.Another study appearing in this issue study of CNS anomalies in fetuses with complex clubfoot also showed additionally diagnosed CNS anomalies in 4 cases on MRI. MRI yielded supplementary findings that were not visible on ultrasound in 6 cases. Although the number of cases is small, it was able to be shown, as in other studies, that a certain percentage of CNS anomalies is able to be evaluated on an additional or supplementary basis on MRI.Since intrauterine MRI has been becoming increasingly important in recent years, it is necessary to determine when MRI is indicated. There is general consensus in the literature that MRI is not a screening method for detecting fetal anomalies but should be viewed as a supplementary method to ultrasound 8 9 10. However, MRI application in pregnancy is increasing. Intrauterine MRI is most commonly used in the case of abnormal ultrasound findings regarding the CNS 11 12 13. This includes morphological evaluation of malformations and recently also of acquired hypoxic-ischemic diseases, bleeding and inflammation such as CMV infections. Thoracic and abdominal malformations are also indications for MRI for the evaluation of the lung volume in diaphragmatic defects and in the case of suspicion of esophageal atresia abnormal placentation. Further possible indications for the use of MRI include monochorial multiple pregnancies with a feto-fetal transfusion syndrome (for the evaluation of neurological development) and select cases with known diseases and syndromes 14. The majority of studies for comparing intrauterine MRI to sonographic diagnosis include a small number of cases with limited or no follow-up. Data regarding sensitivities, specificities, and positive predictive values is limited. Many studies simply calculate the difference in percentages on the basis of a small number of cases. The best available data is in regard to CNS anomalies. In one of the few meta-analyses including 34 studies and documented follow-up in 959 fetuses, intrauterine MRI was correct in 91 % of cases which was an increase of 16 % above that achieved by ultrasound 15. This means a significant diagnostic gain for specific issues. However, it must be taken into consideration that the analysis includes a period of 20 years and fetal neurosonography has made major progress in this time. The diagnostic gain would tend to be smaller today. In many studies the level of experience of the ultrasound examiners often remains unclear A possible bias is also that an examiner with less experience determines an indication for intrauterine MRI faster and more frequently and can thus gain more information compared to highly specialized, experienced ultrasound examiners in prenatal centers. Since advanced training in prenatal diagnosis is becoming increasingly difficult due to the transfer of centers to ambulatory practices, there is a certain risk that crash courses or brief internships in ultrasound will result in intrauterine MRI playing an additional role in fetal differential diagnosis and in the confirmation of findings. Because intrauterine MRI is stressful for pregnant women, indiscriminate indication for MRI cannot be recommended even if no fetal damage is to be expected provided that the appropriate safety measures are observed (examination duration of approx. 30 minutes and implementation of MRI after 18 weeks of gestation). After a properly performed ultrasound examination, little additional morphological information can be gained from MRI 16. However, in the case of an unclear sonographic finding or in the event of therapeutic consequences for the care of the fetus or for the birth, MRI is an excellent supplementary method to ultrasound. Concretely, this means ultrasound first. If the finding is not clear, intrauterine MRI can be used as an adjunct method. In this way the cost-benefit ratio can be optimized. The gains achieved by MRI compared to US depend on the quality of the examination and thus on the expertise of the examiner in both methods. The indications for fetal MRI should also follow defined standards based on a protocol adapted to the particular clinical issue 16.

Quality Requirements for the early Fetal Ultrasound Assessment at 11-13+6 Weeks of Gestation (DEGUM Levels II and III)

The early fetal ultrasound assessment at 11 - 13(+6) weeks of gestation remains the cornerstone of care despite the progress in diagnosing fetal chromosomal defects using cell-free fetal DNA (cffDNA) from the maternal circulation. The measurement of nuchal translucency (NT) allows the risk calculation for the fetal trisomies 21, 18 and 13 but also gives information on those fetal chromosomal defects which are at present unable to be detected using cffDNA. Nuchal translucency is the only auditable parameter at 11 - 13(+6) weeks and gives thus information on the quality of the first trimester anomaly scan. In addition it gives indirect information on the risks for fetal defects and for cardiac anomalies. Also the chances for a healthy live baby can be estimated. As experience with first trimester anomaly scanning increases, and the resolution of the ultrasound equipment has increased substantially, more and more details of the fetal anatomy become accessible at the first trimester scan. Therefore fetal anatomical defects and complex anomalies have become amenable to examination in the first trimester. This guideline describes compulsory and optional parameters for investigation at the first trimester scan and outlines a structured method of examining a first trimester fetus at 11 - 13(+6) weeks of gestation.

Strømme Syndrome Is a Ciliary Disorder Caused by Mutations in CENPF

Strømme syndrome was first described by Strømme et al. (1993) in siblings presenting with "apple peel" type intestinal atresia, ocular anomalies and microcephaly. The etiology remains unknown to date. We describe the long-term clinical follow-up data for the original pair of siblings as well as two previously unreported siblings with a severe phenotype overlapping that of the Strømme syndrome including fetal autopsy results. Using family-based whole-exome sequencing, we identified truncating mutations in the centrosome gene CENPF in the two nonconsanguineous Caucasian sibling pairs. Compound heterozygous inheritance was confirmed in both families. Recently, mutations in this gene were shown to cause a fetal lethal phenotype, the phenotype and functional data being compatible with a human ciliopathy [Waters et al., 2015]. We show for the first time that Strømme syndrome is an autosomal-recessive disease caused by mutations in CENPF that can result in a wide phenotypic spectrum.

The special role of ultrasound for screening, staging and surveillance of malignant ovarian tumors: distinction from other methods of diagnostic imaging

Ovarian cancer is the most aggressive gynecologic malignancy, with a 5-year survival rate ranging around 40%. A crucial factor influencing the prognosis is early detection of a suspicious mass and referral to a gynecologic oncology center for further diagnosis, staging and debulking surgery. Here, we present the different imaging methods ultrasound (US), magnetic resonance imaging, computer tomography (CT) and 18F-fluoro-deoxyglucose positron emission tomography (PET)/CT that are used for the characterization, diagnosis, staging and surveillance of ovarian cancer. In this review, we focus on US and discuss in detail the advantages and the limitations, as well as the appropriate indications for each of the individual imaging techniques.

Exome sequencing identifies mutations in KIF14 as a novel cause of an autosomal recessive lethal fetal ciliopathy phenotype

Gene discovery using massively parallel sequencing has focused on phenotypes diagnosed postnatally such as well-characterized syndromes or intellectual disability, but is rarely reported for fetal disorders. We used family-based whole-exome sequencing in order to identify causal variants for a recurrent pattern of an undescribed lethal fetal congenital anomaly syndrome. The clinical signs included intrauterine growth restriction (IUGR), severe microcephaly, renal cystic dysplasia/agenesis and complex brain and genitourinary malformations. The phenotype was compatible with a ciliopathy, but not diagnostic of any known condition. We hypothesized biallelic disruption of a gene leading to a defect related to the primary cilium. We identified novel autosomal recessive truncating mutations in KIF14 that segregated with the phenotype. Mice with autosomal recessive mutations in the same gene have recently been shown to have a strikingly similar phenotype. Genotype-phenotype correlations indicate that the function of KIF14 in cell division and cytokinesis can be linked to a role in primary cilia, supported by previous cellular and model organism studies of proteins that interact with KIF14. We describe the first human phenotype, a novel lethal ciliary disorder, associated with biallelic inactivating mutations in KIF14. KIF14 may also be considered a candidate gene for allelic viable ciliary and/or microcephaly phenotypes.

[Current aspects of obstetric ultrasound in the screening setting]

Screening ultrasound during pregnancy has an established role and a defined scope that has increased over the years. Diagnostic possibilities with newer ultrasound systems can help in particular in referral settings and for a more detailed analysis of various fetal organ systems. In particular for the fetal heart there is a clear benefit with regard to neonatal morbidity and mortality.

Array comparative genomic hybridization in prenatal diagnosis of first trimester pregnancies at high risk for chromosomal anomalies

Objective

To describe the diagnostic performance of array comparative genomic hybridization (aCGH) as a potential first line diagnostic method in first trimester high risk pregnancies.

Method

In a retrospective study we performed aCGH using a targeted array BAC platform (Constitutional Chip® 4.0, PerkinElmer, Turku Finland, median resolution 600 kB) and the Affymetrix Cytogenetics® Whole Genome 2.7 M array (at a resolution of 400kB) on 100 anonymized prenatal samples from first trimester high risk pregnancies with normal conventional karyotype. We studied the technical feasibility and turn-around-time as well as the detection rate of pathogenic submicroscopic chromosome anomalies and CNVs of unknown significance.

Results

We obtained results in 98 of 100 samples in 3 to a maximum of 5 days after DNA extraction. At the given resolution we did not identify any additional pathogenic CNVs but two CNVs of unknown significance in the chromosomal regions 1q21.1q21.2 (deletion) and 5p15.33 (duplication) (2%).

Conclusion

In accordance with a growing number of reports this study supports the concept that aCGH at a resolution of 400-600kB may be used as a first line prenatal diagnostic test with high diagnostic safety and rapid turn-around time in high-risk first trimester pregnancies. Detection rate of CNVs of unknown significance, considered as a major hindrance for replacing conventional karyotyping by aCGH, is 2%, but the diagnosis of additional submicroscopic anomalies in this heterogeneous group of patients seems to be rare.

Prenatal counseling--implications of the cultural background of pregnant women on information processing, emotional response and acceptance

PURPOSE

Providing information about prenatal diagnosis (PND) that leads to an informed decision is ethically and psychologically challenging, especially in an intercultural context. The aim was to investigate cultural differences in information processing, test interpretation, evaluation of an established information leaflet, emotional response during screening and acceptance of PND.

MATERIALS AND METHODS

This prospective study compared 30 pregnant Turkish immigrants with 30 women from Switzerland and countries within the European Union (EU). They completed a questionnaire prior to (T1) and after risk assessment between 11-14 weeks (T2) and after receiving the results (T3). The questionnaire focused on the perception of, experiences with and knowledge about the risk assessment and included the hospital anxiety and depression scale (HADS). χ(2) tests were used for dichotomous variables and Student's t-tests for scores on perception, experience, knowledge, depression and anxiety. Groups were compared over time by 2-factorial ANOVA.

RESULTS

Regarding the 6 questions on knowledge, the rate of correct answers was between 32.2% and 62.5% at T1 and 35.1% and 75.0% at T2. The Turkish women's knowledge level was significantly lower. They rated the information leaflet as less helpful and found the counseling significantly more unsettling. The acceptance of PND was higher in Turkish women.

CONCLUSION

Considering the information and knowledge deficits, informed consent was not given in every case, especially in Turkish women. Nevertheless, the acceptance of PND was good. Further studies will have to focus on counseling strategies that take into account the specific needs and expectations of pregnant women with different cultural backgrounds.

Is a routine ultrasound in the third trimester justified? Additional fetal anomalies diagnosed after two previous unremarkable ultrasound examinations

PURPOSE

The detection of fetal structural abnormalities is a routine part of antenatal care. Ultrasound examination policies vary among European countries. An additional ultrasound for fetal structural anomalies in the 3 rd trimester seems important for many reasons. Some abnormalities develop or first become apparent later in pregnancy. The aim of the study was to analyze the rate of previously undetected structural abnormalities in the 3 rd trimester.

MATERIALS AND METHODS

8074 fetuses were examined in this prospective study between 1998 and 2008. All received an examination at 11 - 14 weeks and 79 % (6378 / 8074) of these fetuses also received an ultrasound at 20 - 24 weeks. If both of the examinations did not detect structural abnormalities, the fetuses were included in the study group and received an ultrasound at 28 - 32 weeks (n = 5044). New structural abnormalities in the 3 rd trimester were analyzed. The outcome was available in 96 % of the cases.

RESULTS

The overall incidence of fetal malformations was 3.6 % (n = 289), of which 40 % (116 / 289) were diagnosed at 11 - 14 weeks. The following 2nd trimester scan revealed 102 (35 %) new fetal malformations. An additional 44 (15 %) structural abnormalities were found in the 3 rd trimester. These were mainly abnormalities of the urogenital system (n = 18). There were also anomalies of the cardiovascular system (n = 9), the gastrointestinal system (n = 6) and the central nervous system (n = 4). One of the cases had a previously undiagnosed abnormal karyotype.

CONCLUSION

The ultrasound examination in the 3 rd trimester is of additional benefit and can detect previously unknown structural abnormalities. These findings are relevant for perinatal management and postnatal follow-up.

Fetal polydactyly: a study of 24 cases ascertained by prenatal sonography

Records of 24 pregnancies with fetal polydactyly were reviewed for the type of polydactyly, family history, associated sonographic findings, genetic testing, and postnatal/postmortem examination findings. The importance of fetal polydactyly can be mainly elucidated by the family history and absent or associated anomalies on a specialized malformation scan. Fetal karyotyping diagnoses frequent chromosomal anomalies in about half of cases with additional malformations, and array comparative genomic hybridization may be a future means of detecting cryptic chromosomal aberrations. Syndromic disorders of monogenic origin demand a careful interdisciplinary clinical assessment for establishing a clinical diagnosis and prognosis for the outcome of the child.

Determination of fetal chromosome aberrations from fetal DNA in maternal blood: has the challenge finally been met?

The analysis of cell-free fetal nucleic acids in maternal blood for prenatal diagnosis has been transformed by several recent profound technology developments. The most noteworthy of these are 'digital PCR' and 'next-generation sequencing' (NGS), which might finally deliver the long-sought goal of noninvasive detection of fetal aneuploidy. Recent data, however, indicate that NGS might even be able to offer a much more detailed appraisal of the fetal genome, including paternal and maternal inheritance of point mutations for mendelian disorders such as β-thalassaemia. Although these developments are very exciting, in their current form they are still too complex and costly, and will need to be simplified considerably for their optimal translation to the clinic. In this regard, targeted NGS does appear to be a step in the right direction, although this should be seen in the context of ongoing progress with the isolation of fetal cells and with proteomic screening markers.

Potential markers of preeclampsia--a review

Preeclampsia is a leading cause of maternal and fetal/neonatal mortality and morbidity worldwide. The early identification of patients with an increased risk for preeclampsia is therefore one of the most important goals in obstetrics. The availability of highly sensitive and specific physiologic and biochemical markers would allow not only the detection of patients at risk but also permit a close surveillance, an exact diagnosis, timely intervention (e.g. lung maturation), as well as simplified recruitment for future studies looking at therapeutic medications and additional prospective markers. Today, several markers may offer the potential to be used, most likely in a combinatory analysis, as predictors or diagnostic tools. We present here the current knowledge on the biology of preeclampsia and review several biochemical markers which may be used to monitor preeclampsia in a future, that, we hope, is not to distant from today.

[Pregnant women's assessment and level of knowledge of prenatal counseling]

PURPOSE

Informed decision making and informed consent prior to any intervention are crucial in the ethically and psychologically complex field of prenatal diagnosis (PND). The aim of this study was to investigate whether and to what extent pregnant women understand the information provided by their physicians.

MATERIALS AND METHODS

Fifty pregnant women in the first trimester answered a structured questionnaire after their first visit between 7 to 10 weeks of gestation that routinely includes basic prenatal counseling. A special focus was put on information transfer, knowledge about and understanding of prenatal tests, as well as previous experiences with PND. The results were analyzed with regard to differences due to background, educational level and previous experiences with PND.

RESULTS

The maternal mean age was 31.1 years (SD 6.7). 38 patients (76 %) had at least one previous pregnancy and two thirds of them had experiences with PND. Their experience was mainly positive. About three quarters of the women stated that they had been informed about the test methods during the consultation and had understood the explanations. Uncertainty was reported in 12.2 % and 23.3 % of the women said they had further questions. The percentage of questions related to appropriate understanding that were answered correctly was only 44 % to 77.5 %. The percentage of correct answers was lower in women without experience with PND, with a lower educational level and born in countries outside the EU and Switzerland.

CONCLUSION

Pregnant women are relatively well informed about prenatal tests. Their actual knowledge of the meaning of the tests, however, seems to be incomplete. Especially in the case of immigrants and women without previous experience with PND, it is therefore doubtful whether the preconditions for an informed consent are met. Further research needs to focus on more helpful information and individually adapted counseling concepts for decision making in PND.

[Ultrasound findings in fetal infection]

Infections acquired in utero or during the birth process are a significant cause of fetal and neonatal mortality and an important contributor to early and later childhood morbidity. Advances in ultrasound, invasive prenatal procedures and molecular diagnostics have allowed in utero evaluation and given rise to more timely and accurate diagnosis in infected fetuses. Transplacental transmission of the infectious agent, even in subclinical maternal infection, may result in a severe congenital syndrome. Prenatal detection of infection is based on fetal sonographic findings and polymerase chain reaction to identify the specific agent. Nevertheless, most affected fetuses appear sonographically normal, but serial scanning may reveal evolving findings. Sonographic fetal abnormalities may be indicative of fetal infections, although they are generally not sensitive or specific. These include growth restriction, hydrops, ventriculomegaly, hydrocephaly, microcephaly, intracranial or hepatic calcifications, ascites, hepatosplenomegaly, echogenic bowel, placentomegaly, and abnormal amniotic fluid volume. When abnormalities are detected on ultrasound, a thorough fetal evaluation is recommended because of potential multiorgan involvement. The sonologist should understand the limitations of ultrasound. Patients should be counseled that ultrasound is not a sensitive test for fetal infection and that a normal fetal anatomy survey cannot reliably predict a favorable outcome.

Sonographische Diagnostik von Trophoblasterkrankungen in der Frühschwangerschaft

Die gestationsbedingten Trophoblasterkrankungen (GTD) werden in metastasierende und nicht metastasierende Läsionen, sowie basierend auf ihrer Morphologie in villöse und nicht-villöse GTD unterteilt. Aufgrund ihrer höheren Inzidenz und des Risikos für eine persistierende gestationsbedingte trophoblastäre Neoplasie (pGTN) ist die frühzeitige Diagnose von Blasen- und Partialmolen im klinischen Alltag bedeutsam. Fortschritte in der Ultraschalltechnologie und die häufigere Anwendung der Transvaginalsonographie in der Frühschwangerschaft haben das klinische und histopathologische Bild molarer Schwangerschaften verändert. Die meisten Fälle werden heutzutage infolge auffälliger Ultraschallbefunde bzw. histologischer Befunde in der Frühschwangerschaft entweder zufällig oder im Rahmen eines Abortgeschehens diagnostiziert. Molare Schwangerschaften fallen durch charakteristische Ultraschallbefunde auf. In der Frühschwangerschaft variiert die Ultraschallsensitivität für Molen zwischen 34 und 56% in Abhängigkeit vom Gestationsalter, sonographischer und histologischer Morphologie, technischer Ausstattung sowie Erfahrung des Untersuchers. Die sonographische Detektionsrate scheint durch histomorphometrische Eigenschaften der hydropischen Villi limitiert zu sein. Das Fehlen typischer Ultraschallbefunde schließt daher eine Mole nicht aus. Wird jedoch die Prädisposition für eine pGTN nicht rechtzeitig erkannt, wirkt sich das ungünstig auf die Prognose aus. Mit zunehmender Nachfrage nach medikamentösem Management von Aborten und Abruptiones, insbesondere wenn keine histologische Aufarbeitung des Schwangerschaftsmaterials erfolgt, ist eine sonographische Evaluation der Chorionstruktur obligatorisch. Bei auffälligen Ultraschallbefunden sind ein operatives Vorgehen und die histologische Untersuchung indiziert.

[Prenatal diagnosis of diastematomyelia and tethered cord - a case report and review of the literature]

Diastematomyelia is a rare form of occult spinal dysraphism. It is characterized by longitudinal clefting and separating of the spinal cord by a bony or fibrous spur. Diastematomyelia is associated with other anomalies, i. e. spina bifida, scoliosis, visceral malformations or anomalies of the overlying skin. Prenatal diagnosis is based on fetal ultrasound supplemented by fetal MRI. We present a case of diastematomyelia and prenatal diagnosis in the 23rd gestational week using routine ultrasound scanning and confirmation by fetal MRI. After vaginal delivery at term, the child's development is normal. Prenatal diagnosis of isolated diastematomyelia is challenging. Management and prognosis are still controversial as only few cases have been reported. Affected fetuses might benefit from early diagnosis enabling surgical intervention before the development of neurological sequelae.

Quality management of nuchal translucency measurement in residents

PURPOSE

The measurement of the nuchal translucency (NT) in the 1st trimester is a sensitive, reliable method to assess the risk of specific fetal chromosomal and other defects. Training, however, is an issue not only among experienced sonographers, but especially for ObGyn residents, since all NT measurements in a true screening setting should fulfil the quality standards. The aim of this study was therefore the evaluation of the learning curve of residents and determination of the number of measurements necessary to achieve acceptable results.

MATERIALS AND METHODS

Between 30th June, 1997 and 8th August, 2003, we included 4450 subsequent pregnant women between 11+0 and 13+6 weeks of gestation referred for an NT scan and prenatal counselling (low and high risk patients) in the study. For analysis of the learning curve in residents, all NT scans performed either by the experienced sonographers only or by residents with less than 70 scans at the end of their training were excluded. As the main quality criterion, the percentage of cases above the median was used. To test for normal distribution of NT scans, the Kolmogorov-Smirnov test was used.

RESULTS

Each of 19 residents fulfilling these criteria performed 131 NT scans (73-242) on average. 13 of 19 residents ultimately met the quality criteria, but the majority of residents achieved good quality only after 100 scans, whereas 6 of 19 never did. Only after at least 50 NT scans, 50% of measurements were above the median, whereas before these 50 scans, NT was usually underestimated.

CONCLUSION

It became obvious that regular supervision and quality control is mandatory to provide exact NT measurements by residents. Based on our results, a minimum of 100 NT scans is recommended before diagnostic application, which is a higher requirement than implemented in widely accepted quality assurance programs.

Two- versus three-dimensional ultrasound in the second and third trimester of pregnancy: impact on recognition and maternal-fetal bonding. A prospective pilot study

OBJECTIVE

To assess the impact of three-dimensional (3D) versus two-dimensional (2D) ultrasound (US) on maternal-fetal bonding.

STUDY DESIGN

Prospective randomized pilot study among low risk women with singleton fetuses in the second and third trimester. Dependent on the randomization pattern, US was commenced either with 2D US or 3D US and the effects were recorded with standardized questionnaires.

RESULTS

Sixty patients were included. Although the quality of 2D US, assessed by the examinator, was superior to 3D US, maternal recognition was higher with 3-D US (P = 0.004). With 2D US, nulliparous patients had significantly more difficulties visualizing the fetus, than multiparous (P = 0.03). However, the maternal preference of 3D US had no significant impact on maternal-fetal bonding.

CONCLUSION

Ultrasound had no significant effect on maternal-fetal bonding. Three-dimensional images may facilitate recognition of the fetus, but 3D US did not have higher impact on maternal-fetal bonding. This finding may be a reason not to consider 3D ultrasound for routine scanning.

[Communication skills for prenatal counselling]

Prenatal counselling is characterized by specific characteristics: A):The communication is about the values of the pregnant woman and her relationship with the child to be. B) The communication deals with patient's images and emotions. C) It is a communication about risks, numbers and statistics. D) Physician and patient deal with important ethical issues. In this specific setting of prenatal diagnosis and care physicians should therefore learn to apply basic principles of patient-centred communication with elements of non directive counselling, patient education and shared decision making. These elements are integrated into a process which comprises the following "steps": 1. Clarification of the patient's objectives and the obstetrician's mandate. 2. The providing of individualized information and education about prenatal tests and investigations. 3. Shared decision making regarding tests and investigations 4. Eventually Breaking (bad, ambivalent) news. 5. Caring for patients with an affected child.