Detection of fetal structural anomalies in a basic first-trimester screening program for aneuploidy

Expectations and basic knowledge in ultrasound screening among pregnant women: A questionnaire survey

OBJECTIVE

This study aimed to evaluate the disparity of the expectations and basic knowledge of prenatal ultrasound (US) screening among pregnant women and make a comparison with the current scientific knowledge and national recommendations. We hypothesize that sociodemographic factors, including age, education, and professional occupation, may be associated with different levels of knowledge.

METHODS

This was a cross-sectional study performed in 2021 of 336 women aged 18 to 46 years in a maternity facility in a tertiary hospital in Portugal. The main outcome measures were questionnaire data from questions divided into four categories (sociodemographic, expectations, knowledge, and final considerations/suggestions). The data were grouped according to the sociodemographic factors (age, educational level, and professional occupation) and analyzed and compared as a function of the social groups as well as overall tendencies.

RESULTS

Our data confirmed a significant discrepancy between the expectations and general knowledge of pregnant women regarding prenatal US when compared with the current scientific knowledge. Importantly, we found that both depended greatly on sociodemographic factors, particularly educational level. This reiterated the importance of conducting effective dissemination actions of current scientific knowledge, focusing on the main objectives of US screening as well as the limitations of the existing technology.

CONCLUSION

This study will help in defining strategies for future dissemination actions aiming to improve current practice and lead to a higher synchrony of expectations towards US between couples and practitioners.

First-Trimester Ultrasound Screening in Routine Obstetric Practice

Technologic advances and ultrasonographer-physician experience in fetal imaging have led to significant improvements in our ability to distinguish between normal and abnormal fetal structural development in the latter part of the first trimester. As a critical component of pregnancy care, assessment of fetal anatomy at the end of the first trimester with a standardized imaging protocol should be offered to all pregnant patients regardless of aneuploidy screening results because it has been demonstrated to identify approximately half of fetal structural malformations. Early identification of abnormalities allows focused genetic counseling, timely diagnostic testing, and subspecialist consultation. In addition, a normal ultrasound examination result offers some degree of reassurance to most patients. Use of cell-free DNA alone for aneuploidy screening while foregoing an accompanying early anatomic evaluation of the fetus will result in many anomalies that are typically detected in the first trimester not being identified until later in pregnancy, thus potentially diminishing the quality of obstetric care for pregnant individuals and possibly limiting their reproductive options, including pregnancy termination.

Trends in Non-invasive Prenatal Screening and Invasive Testing in Denmark (2000-2019) and Israel (2011-2019)

Introduction: Following the wide distribution of non-invasive prenatal genetic screening (NIPS), numerous studies have reported a decline in total invasive tests in the recent years, up to 50–70% in some countries. However, in Denmark and Israel we have not experienced these declines. The objective of our study was to evaluate the trends in NIPS and chromosomal microarray analysis (CMA) use in Denmark and Israel.

Methods: This retrospective study was performed by data acquisition from the Danish Cytogenetics Central Registry throughout the years 2000–2019, and Israeli Public Health Services, Ministry of Health computerized database (from 2011).

Results: Of the 1,243,956 live births registered in Denmark over the years 2000–2019, a relatively steady level of invasive testing around 6% was noted since 2004, as opposed to 13.0% in Israel based on 1,594,962 live births between 2011 and 2019. The average uptake of NIPS was 1.1 ± 0.5% in Denmark vs. 4.3% in Israel (2013–2019). Relatively steady rates of invasive testing were noted in both countries, compared to a slight decline in NIPS in the recent years.

Discussion: The recent decrease in the rates of invasive testing in the NIPS era was not observed in Denmark or in Israel. These results imply that Danish and Israeli women and/or health providers might favor the high resolution and yield of CMA testing over the non-invasiveness of NIPS. We explore and discuss this phenomenon, based on five central factors.

First trimester screening with biochemical markers and ultrasound in relation to non-invasive prenatal testing (NIPT)

Non-invasive prenatal testing (NIPT) is often erroneously received as a diagnostic procedure due to its high discriminatory power in the field of fetal trisomy 21 diagnosis (wording: "NIPT replaces amniocentesis"). Already a look at the methodology of NIPT (statistical gene dose comparison of a primarily maternofetal DNA mixture information at selected sites of the genome) easily reveals that NIPT cannot match the gold standard offered by cytogenetic and molecular genetic analysis procedures from the matrix of the entire human genome (origin: vital fetal cells), neither in diagnostic breadth nor in diagnostic depth. In fact, NIPT in fetal medicine in its current stage of development is a selective genetic search procedure, which can be applied in primary (without indication) or secondary (indication-related) screening. Thus, NIPT competes with established search procedures for this field. Here, the combined nuchal translucency (NT) test according to Nicolaides has become the worldwide standard since 2000. The strength of this procedure is its broad predictive power: NT addresses not only the area of genetics, but also the statistically 10 times more frequent structural fetal defects. Thus, NIPT and NT have large overlaps with each other in the field of classical cytogenetics, with slightly different weighting in the fine consideration. However, NIPT without a systematic accompanying ultrasound examination would mean a step back to the prenatal care level of the 1980s. In this respect, additional fine ultrasound should always be required in the professional application of NIPT. NIPT can thus complement NT in wide areas, but not completely replace it.

Prenatal screening diagnosis and management in the era of coronavirus: the Sardinian experience

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new coronavirus, was first identified in December 2019 in Wuhan, China and spread rapidly, affecting many other countries. The disease is now referred to as coronavirus disease 2019 (COVID-19).The Italian government declared a state of emergency on 31st January 2020 and on 11th March World Health Organization (WHO) officially declared the COVID-19 outbreak a global pandemic. Although the COVID-19 incidence remained considerably lower in Sardinia than in the North Italy regions, which were the most affected, the field of prenatal screening and diagnosis was modified because of the emerging pandemic. Data on COVID-19 during pregnancy are so far limited. Since the beginning of the emergency, our Ob/Gyn Department at Microcitemico Hospital, Cagliari offered to pregnant patients all procedures considered essential by the Italian Ministry of Health. To evaluate the influence of the COVID-19 pandemic on the activities of our center, we compared the number of procedures performed from 10th March to 18th May 2020 with those of 2019. Despite the continuous local birth rate decline, during the 10-week pandemic period, we registered a 20% increment of 1st trimester combined screening and a slight rise of the number of invasive prenatal procedures with a further increase in chorionic villi sampling compared to amniocentesis. Noninvasive prenatal testing remained unvariated. The request for multifetal pregnancy reduction as a part of the growing tendency of voluntary termination of pregnancy in Sardinia increased. The COVID-19 pandemic provides many scientific opportunities for clinical research and study of psychological and ethical issues in pregnant women.

Reduction of multiple pregnancy: Counselling and techniques

The incidence of multiple births has risen in the last few decades. This rise is mainly due to the widespread use of assisted reproduction techniques mainly as a result of increasing maternal age at conception. Twin and higher-order multiple pregnancies are associated with increased risk of perinatal, as well as maternal, mortality and morbidity compared to singleton pregnancies. There can also be psychosocial and socioeconomic implications for women and their families. In this chapter, we aim to discuss the risks associated with multiple pregnancies, the pros and cons of fetal reduction, the current techniques used in clinical practice, and how to approach counselling parents, enabling them to make informed decisions.

The decline of amniocentesis and the increase of chorionic villus sampling in modern perinatal medicine

Objective The aims of this study were to determine the rate of change by type of diagnosis by transabdominal chorionic villus sampling (TA-CVS) vs. amniocentesis for aneuploidy and to describe a successful and intensive international training program for TA-CVS in ongoing pregnancies. Methods We conducted a retrospective cohort study of all deliveries from 2010 to 2018 in Sardinia. All invasive diagnostic procedures are conducted at a single regional perinatal referral center. Descriptive statistics were used to compare data across groups, and inter-correlations between variables were investigated by Pearson's correlation coefficient. We subsequently describe the international trainee experiences in TA-CVS over a 35-year period. Results A total of 101,025 deliveries occurred over 9 years. The number of deliveries (13,413-9143, P < 0.0001) and total invasive diagnostic procedures (1506-858 per year, P = 0.019) declined over this period. The percentage of deliveries undergoing invasive diagnostic procedures remained steady (mean: 12.2%). In 2010, TA-CVS made up 32.3% of all invasive diagnostic procedures, while amniocentesis made up 67.7%. By 2018, TA-CVS made up 61.3% of the invasive diagnostic procedures, and amniocentesis, only 38.7%. The rate of TA-CVS increased over 9 years, while the rate of amniocentesis declined. A total of 236 trainees from 39 different countries and 5 different continents rotated through this site. The average length of stay was 2.4 weeks. Conclusion We demonstrate an increasing prevalence of TA-CVS vs. amniocentesis in the current era of prenatal testing and underscore the importance of continuing to train specialists skilled in TA-CVS. Our global operative experience is feasible and sustainable and will have a lasting impact on physicians conducting invasive fetal procedures.

Fetal arthrogryposis multiplex congenita/fetal akinesia deformation sequence (FADS)-Aetiology, diagnosis, and management

Arthrogryposis multiplex congenita (AMC) refers to an aetiologically heterogenous condition, which consists of joint contractures affecting two or more joints starting prenatally. The incidence is approximately one in 3000 live births; however, the prenatal incidence is higher, indicating a high intrauterine mortality. Over 320 genes have been implicated showing the genetic heterogeneity of the condition. AMC can be of extrinsic aetiology resulting from intrauterine crowding secondary to congenital structural uterine abnormalities (eg, bicornuate or septate uterus), uterine tumors (eg, fibroid), or multifetal pregnancy or intrinsic/primary/fetal aetiology, due to functional abnormalities in the brain, spinal cord, peripheral nerves, neuromuscular junction, muscles, bones, restrictive dermopathies, tendons and joints. Unlike many of the intrinsic/primary/fetal causes which are difficult to treat, secondary AMC can be treated by physiotherapy with good response. Primary cases may present prenatally with fetal akinesia associated with joint contractures and occasionally brain abnormalities, decreased muscle bulk, polyhydramnios, and nonvertex presentation while the secondary cases usually present with isolated contractures. Complete prenatal and postnatal investigations are needed to identify an underlying aetiology and provide information regarding its prognosis and inheritance, which is critical for the obstetrical care providers and families to optimize the pregnancy management and address future reproductive plans.

Diagnosis of Fetal Structural Anomalies at 11 to 14 Weeks

OBJECTIVES

To assess the performance of first-trimester ultrasound (US) in identifying major fetal structural abnormalities in an unselected population.

METHODS

We conducted a retrospective analysis of all pregnancies that underwent the 11- to 14-week scan in the Fetal Medicine Department of Filantropia Hospital in Bucharest, which were prospectively examined within our screening program. The purpose of the first-trimester US was to evaluate the risk for chromosomal abnormalities and to conduct fetal anatomic examination using a detailed protocol.

RESULTS

Our population consisted of 7480 pregnant patients (7576 fetuses). The follow-up was completed for 6045 patients (6114 fetuses). The prevalence of major structural anomalies was 1.89%. In the first trimester, we identified 79% of all major structural anomalies. The highest detection rates were achieved for abdominal wall defects (100%), major central nervous system anomalies (88%), cardiac defects (74%), and skeletal anomalies (71%). The nuchal translucency was increased in 35% of the cases with structural anomalies, and 95% of these were diagnosed in the first trimester. Seventy percent of the patients who presented with structural anomalies and a normal nuchal translucency were diagnosed in the first trimester.

CONCLUSIONS

Our results emphasize the importance of performing a detailed US examination at 11 to 14 weeks' gestation in identification of fetal structural defects.

Fetal Anatomic Imaging Between 11 and 14 Weeks Gestation

Fetal imaging between 11 and 14 weeks is a standard component of prenatal risk assessment for aneuploidy. Evaluating the fetus during this gestational age window provides the opportunity to reliably examine anatomic structures. Using a defined imaging protocol, approximately 50% of major abnormalities can be detected. Some abnormalities should almost always be detected, some may be detected on occasion and others are not currently detectable. Imagers must be familiar with embryologic patterns of development and natural history of anomalies. Patients must be informed of the limitations of early anatomic evaluation. Currently, early anatomic evaluation does not replace the standard second trimester evaluation.

Fetal brain anomalies detection during the first trimester: expanding the scope of antenatal sonography

PURPOSE

The purpose of this study was to describe fetal brain anomalies identified during nuchal translucency (NT) examination and their clinical management.

MATERIALS AND METHODS

In this retrospective study, we evaluated charts of pregnant women performed the first trimester scan (FTS) between 1.1.2011 and 31.12.14 in a tertiary referral center. Study population consisted of 952 patients scheduled for routine NT scan for aneuploidy screening between 11.0 and 13.6 gestational weeks, and 32 referred patients due to suspicious CNS finding during previous NT scan. Targeted brain assessment was performed according to clinical judgment during routine scans and in all referred cases. Patients with suspicious CNS findings were referred to pregnancy termination or further evaluation including genetic consultation and second trimester anatomical scan.

RESULTS

Thirty-one fetuses were diagnosed with variable brain anomalies. Acrania/anencephaly was the most common defect (nine cases) while the rarest findings were inter-hemispheric cyst, microcephaly, and Walker-Warburg Syndrome (one case each). Genetic testing revealed variable results. Twenty-six (83.9%) couples decided to terminate their pregnancies.

CONCLUSIONS

The current report highlights the evolving ability to detect CNS malformation during NT scan. FTS novel findings expand our embryological understanding of early fetal development. While severe anomalies can be managed by early termination, other defects necessitate comprehensive evaluation and repetitive imaging.

Adverse fetal outcome: is first trimester ultrasound and Doppler better predictor than biomarkers?

AIMS AND OBJECTIVES

To evaluate the predictive value of first trimester biomarkers and ultrasound in determining adverse fetal outcomes in a low risk Asian population.

MATERIAL AND METHOD

All low risk, singleton pregnancies between 11 and 14 weeks gestation underwent ultrasound with uterine artery Doppler along with PAPP-A and free β-hCG estimation, and were followed till delivery to observe the outcome. The adverse fetal outcomes detected were structural anomaly, aneuploidy, intrauterine growth restriction, preterm birth and stillbirth (SB).

RESULTS

Out of 3500 women screened, 417 cases had adverse fetal outcome in the absence of maternal complication, 2151 had normal outcome. Major structural anomaly was detected in first trimester in 17/28 (60.7%) cases. The most important markers for adverse fetal outcome were increased uterine artery pulsatility index (UPI) (p = 0.028, OR 1.5, 95% CI: 1.05-2.38, AUC 0.56) for IUGR, nuchal translucency (p = 0.001, OR 1.7, 95% CI: 1.11-2.77, AUC 0.60) for major anomaly and low PAPP-A (p = 0.017, OR -0.075, 95% CI: 0.87-0.98, AUC 0.621) for SB.

CONCLUSION

UPI, NT and PAPP-A in the first trimester are significant markers of adverse fetal outcome, although the sensitivity and specificity are not high they have a high negative predictive value.

Ultrasound screening: Status of markers and efficacy of screening for structural abnormalities

Aneuploidy is a major cause of perinatal morbidity and mortality and can have a significant impact on expecting parents and their families. With early screening and diagnosis it is important to be able to educate parents regarding the potential impact of the diagnosis. This knowledge allows parents the opportunity to consider management options early in the pregnancy, permitting more time to mentally and emotionally prepare both for the course of the pregnancy, and after the birth of the child should the pregnancy continue. Prenatal screening provides pregnant women a non-invasive risk assessment for the most common aneuploidies. Those who are considered "high-risk" then have the option for additional diagnostic (invasive) testing. Prior to the 1980s, prenatal screening consisted of risk assessment through maternal age; however, with the advent of maternal serum biochemical analysis and ultrasound, the field of prenatal screening developed significantly. As biochemical and sonographic advances continued into the 1990s, the emphasis shifted to risk assessment in the first trimester, with the combination of maternal serum analytes and sonographic evaluation of the nuchal translucency.(1) Within the last decade, the introduction of non-invasive screening (NIPT/S) has shown great impact on the expansion and evolving practice of prenatal screening. Although in many places the standard for prenatal testing continues to include maternal serum analytes and sonographic evaluation, the role of each marker alone and in combination remains important. In the era of increasingly available screening tests, especially with NIPT/(NIPS), this article attempts to review the current role of ultrasound in prenatal care and elucidate the role of ultrasound markers in prenatal screening.

Soft markers for aneuploidy following reassuring first trimester screening: what should be done?

PURPOSE OF REVIEW

The present article aims to review the current role of the soft markers on the second trimester ultrasound (STUS) in women after reassuring first trimester screening (FTS) in singleton pregnancies.

RECENT FINDINGS

Improvements in the FTS and the recent implementation of noninvasive prenatal testing (NIPT) for common aneuploidies have important impact on the prevalence of these conditions in the STUS. Some studies suggest that soft markers in the second trimester of the fetus without structural anomalies have a minor or no role in Down syndrome detection in a prescreened population with reassuring results. However, NIPT could be offered as a next step in the management of such pregnancies if the calculated new composite risk (NCR) for aneuploidy is increased. In the case of reassuring results, pregnancy follow-up for certain markers is advised.

SUMMARY

NIPT has emerged as a new method of prenatal testing and is feasible in the second trimester in women with increased NCR. However, apart from the Down syndrome screening, STUS screening remains a powerful tool in screening for other fetal aneuploidies, structural anomalies and pathological placental conditions and detection of specific soft markers that require pregnancy follow-up.

Contingent non-invasive prenatal testing: an opportunity to improve non-genetic aspects of fetal aneuploidy screening

BACKGROUND

Several countries today struggle with suboptimal performances in many aspects of the fetal aneuploidy screening process and consider introducing non-invasive prenatal screening (NIPT) as a solution. In this study, costs and benefits of different scenarios for contingent NIPT screening in Belgium are evaluated with respect to partial redistribution of the national screening budget into quality improving measures for those screening activities that will be maintained when full NIPT screening is implemented.

METHODS

Data from the Belgian National Institute for Health and Disability Insurance and the Study Centre for Perinatal Epidemiology were used in modeled calculations of medical and economic impact of NIPT after prior conventional screening (1) at thresholds 1:300 and 1:600, and (2) at current and improved screening sensitivity.

RESULTS

Contingent NIPT screening under current screening conditions would maintain today's 7.9(0)/000 live birth prevalence of Down syndrome (LBPD) at an 11% reduction of overall short-term costs. Lowering the screening threshold to 1:600 or increasing sensitivity by 10% would reduce LBPD to 7(0)/000 at a maximum 3% increase of overall short-term costs.

CONCLUSION

Today, in Belgium and in many other countries, full NIPT screening is considered too expensive for immediate introduction into the national fetal aneuploidy screening program. Contingent NIPT screening is both clinically and economically beneficial. A temporary contingent NIPT protocol allows for reinvesting economic savings into optimization of those screening aspects, which are to be maintained in parallel to full NIPT screening.

#36: Prenatal aneuploidy screening using cell-free DNA

Recent advances in technology have created exciting opportunities to expand and improve genetic testing options that are available to women during pregnancy. However, the novelty and complexity of these technologies, combined with the commercial interest to implement these tests rapidly into routine clinical care, have created challenges for physicians and patients and potentially will lead to misunderstanding, misuse, and unintended consequences. The purpose of this document was to aid clinicians in their day-to-day practice of counseling patients regarding prenatal aneuploidy testing options with cell-free DNA screening, which includes how it compares to current testing methods, potential benefits and harms, and its limitations and caveats.

Recommendations on routine mid-trimester anomaly scan

The purpose of this paper is to discuss the minimal requirements of the routine mid-trimester anomaly scan in Asian countries after taking into account various factors, including local circumstances, medical practice, guidelines, and availability of experienced sonographers and high-resolution ultrasound machines, which affect the prenatal detection rate of fetal anomalies. In general, a routine mid-trimester anomaly scan includes the assessment of the number of fetuses, fetal cardiac activity, size, anatomy, liquor and placental location. The most controversial issue is which fetal structures should at least be examined. We discussed the requirements of a basic routine scan, as well as the optional views, which can be obtained if feasible to improve the detection of fetal, placental or maternal abnormalities. Routine anomaly scan remains a clinical challenge.

What is the importance of second-trimester "soft markers" for trisomy 21 after an 11- to 14-week aneuploidy screening scan?

OBJECTIVES

The purpose of this study was to evaluate the importance of second-trimester "soft markers" for trisomy 21 after an 11- to 14-week aneuploidy screening scan.

METHODS

We conducted a retrospective cohort study of consecutive patients referred for measurement of the nuchal translucency (NT) as part of a screening protocol for aneuploidy. Patients who returned for an anatomic survey between 16 and 20 weeks' gestation were evaluated. The sonographic markers and anomalies associated with the detection of trisomy 21 in the second trimester were analyzed.

RESULTS

There were 42 fetuses (0.4%) with trisomy 21 identified in the study cohort of 9692 patients. Trisomy 21 was suspected at the NT scan in 28 fetuses (67%) and at the second-trimester anatomic survey in 14 (33%). In fetuses first suspected of having trisomy 21 in the second trimester, 9 of 14 had normal anatomic survey results, and 5 of 14 had congenital malformations. All 14 fetuses had soft markers for aneuploidy. A thickened nuchal fold was identified in 5 of 9 fetuses with trisomy 21 and normal anatomic survey results, all of whom had an NT of less than 3.0 mm at the initial screening scan.

CONCLUSIONS

Second-trimester soft markers, especially a thickened nuchal fold, remain important observations in the detection of trisomy 21 by sonography among fetuses who have had first-trimester sonographic screening for aneuploidy.